refactor: remove old useless exceptions

Major codebase cleanup

.gitattributes

@@ -0,0 +1 @@
+* -text

.github/workflows/tagged-release.yml

@@ -11,6 +11,11 @@ jobs:
     runs-on: "ubuntu-latest"
 
     steps:
+      - name: Setup Java
+        uses: actions/setup-java@v3
+        with:
+          distribution: 'adopt'
+          java-version: '11'
       - name: Clone repository
         uses: GuillaumeFalourd/clone-github-repo-action@main
         with:

.gitignore

@@ -1,11 +1,18 @@
-.vscode
-.gradle
-.ignore
-/out
-/build
-/bin
-/dst
-/*.js
-!/build.js
-/dead-code
-/Metadata.java
+*
+
+!/src
+!/src/**/*
+
+/src/assets/js/ts.js
+
+!/tests
+!/tests/**/*
+
+!/.github
+!/.github/**/*
+
+!/.gitignore
+!/.gitattributes
+!/build.js
+!/LICENSE
+!/README.md

README.md

@@ -2,33 +2,28 @@
 
 **NOTE: This had nothing to do with Microsoft's dialect of EcmaScript**
 
-**WARNING: Currently, this code is mostly undocumented. Proceed with caution and a psychiatrist.**
+**WARNING: Currently, this code is undocumented. Proceed with caution and a psychiatrist.**
 
-JScript is an engine, capable of running EcmaScript 5, written entirely in Java. This engine has been developed with the goal of being easy to integrate with your preexisting codebase, **THE GOAL OF THIS ENGINE IS NOT PERFORMANCE**. My crude experiments show that this engine is 50x-100x slower than V8, which, although bad, is acceptable for most simple scripting purposes.
+JScript is an engine, capable of running EcmaScript 5, written entirely in Java. This engine has been developed with the goal of being easy to integrate with your preexisting codebase, **THE GOAL OF THIS ENGINE IS NOT PERFORMANCE**. My crude experiments show that this engine is 50x-100x slower than V8, which, although bad, is acceptable for most simple scripting purposes. Note that although the codebase has a Main class, this isn't meant to be a standalone program, but instead a library for running JavaScript code.
 
 ## Example
 
-The following will create a REPL using the engine as a backend. Not that this won't properly log errors. I recommend checking out the implementation in `Main.main`:
+The following is going to execute a simple javascript statement:
 
 ```java
-var engine = new PolyfillEngine(new File("."));
-var in = new BufferedReader(new InputStreamReader(System.in));
-engine.start();
+var engine = new Engine(false);
+// Initialize a standard environment, with implementations of most basic standard libraries (Object, Array, Symbol, etc.)
+var env = Internals.apply(new Environment());
 
-while (true) {
-    try {
-        var raw = in.readLine();
+// Queue code to load internal libraries and start engine
+var awaitable = engine.pushMsg(false, env, new Filename("tmp", "eval"), "10 + Math.sqrt(5 / 3)", null);
+// Run the engine on the same thread, until the event loop runs empty
+engine.run(true);
 
-        var res = engine.pushMsg(false, engine.global(), Map.of(), "<stdio>", raw, null).await();
-        Values.printValue(engine.context(), res);
-        System.out.println();
-    }
-    catch (EngineException e) {
-        try {
-            System.out.println("Uncaught " + e.toString(engine.context()));
-        }
-        catch (InterruptedException _e) {  return; }
-    }
-    catch (IOException | InterruptedException e) { return; }
-}
+// Get our result
+System.out.println(awaitable.await());
 ```
+
+## NOTE:
+
+To setup the typescript bundle in your sources, run `node build.js init-ts`. This will download the latest version of typescript, minify it, and add it to your src/assets folder. If you are going to work with the `node build.js debug|release` command, this is not a necessary step.

build.js

@@ -1,19 +1,9 @@
 const { spawn } = require('child_process');
 const fs = require('fs/promises');
 const pt = require('path');
-const { argv } = require('process');
+const { argv, exit } = require('process');
+const { Readable } = require('stream');
 
-const conf = {
-    name: "java-jscript",
-    author: "TopchetoEU",
-    javahome: "",
-    version: argv[3]
-};
-
-console.log(conf)
-
-if (conf.version.startsWith('refs/tags/')) conf.version = conf.version.substring(10);
-if (conf.version.startsWith('v')) conf.version = conf.version.substring(1);
 
 async function* find(src, dst, wildcard) {
     const stat = await fs.stat(src);
@@ -38,9 +28,9 @@ async function copy(src, dst, wildcard) {
     await Promise.all(promises);
 }
 
-function run(cmd, ...args) {
+function run(suppressOutput, cmd, ...args) {
     return new Promise((res, rej) => {
-        const proc = spawn(cmd, args, { stdio: 'inherit' });
+        const proc = spawn(cmd, args, { stdio: suppressOutput ? 'ignore' : 'inherit' });
         proc.once('exit', code => {
             if (code === 0) res(code);
             else rej(new Error(`Process ${cmd} exited with code ${code}.`));
@@ -48,7 +38,85 @@ function run(cmd, ...args) {
     })
 }
 
-async function compileJava() {
+async function downloadTypescript(outFile) {
+    try {
+        // Import the required libraries, without the need of a package.json
+        console.log('Importing modules...');
+        await run(true, 'npm', 'i', 'tar', 'zlib', 'uglify-js');
+        await fs.mkdir(pt.dirname(outFile), { recursive: true });
+        await fs.mkdir('tmp', { recursive: true });
+
+        const tar = require('tar');
+        const zlib = require('zlib');
+        const { minify } = await import('uglify-js');
+
+        // Download the package.json file of typescript
+        const packageDesc = await (await fetch('https://registry.npmjs.org/typescript/latest')).json();
+        const url = packageDesc.dist.tarball;
+
+        console.log('Extracting typescript...');
+        await new Promise(async (res, rej) => Readable.fromWeb((await fetch(url)).body)
+            .pipe(zlib.createGunzip())
+            .pipe(tar.x({ cwd: 'tmp', filter: v => v === 'package/lib/typescript.js' }))
+            .on('end', res)
+            .on('error', rej)
+        );
+
+        console.log('Compiling typescript to ES5...');
+
+        const ts = require('./tmp/package/lib/typescript');
+        const program = ts.createProgram([ 'tmp/package/lib/typescript.js' ], {
+            outFile: "tmp/typescript-es5.js",
+            target: ts.ScriptTarget.ES5,
+            module: ts.ModuleKind.None,
+            downlevelIteration: true,
+            allowJs: true,
+        });
+        program.emit();
+
+        console.log('Minifying typescript...');
+
+        const minified = minify((await fs.readFile('tmp/typescript-es5.js')).toString());
+        // const minified = { code: (await fs.readFile('tmp/typescript-es5.js')).toString() };
+        if (minified.error) throw minified.error;
+
+        // Patch unsupported regex syntax
+        minified.code = minified.code.replaceAll('[-/\\\\^$*+?.()|[\\]{}]', '[-/\\\\^$*+?.()|\\[\\]{}]');
+
+        const stream = await fs.open(outFile, 'w');
+
+        // Write typescript's license
+        await stream.write(new TextEncoder().encode(`
+/*! *****************************************************************************
+Copyright (c) Microsoft Corporation. All rights reserved.
+Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+this file except in compliance with the License. You may obtain a copy of the
+License at http://www.apache.org/licenses/LICENSE-2.0
+
+THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
+WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
+MERCHANTABLITY OR NON-INFRINGEMENT.
+
+See the Apache Version 2.0 License for specific language governing permissions
+and limitations under the License.
+
+The following is a minified version of the unmodified Typescript 5.2
+***************************************************************************** */
+`));
+
+        await stream.write(minified.code);
+        console.log('Typescript bundling done!');
+    }
+    finally {
+        // Clean up all stuff left from typescript bundling
+        await fs.rm('tmp', { recursive: true, force: true });
+        await fs.rm('package.json');
+        await fs.rm('package-lock.json');
+        await fs.rm('node_modules', { recursive: true });
+    }
+}
+async function compileJava(conf) {
     try {
         await fs.writeFile('Metadata.java', (await fs.readFile('src/me/topchetoeu/jscript/Metadata.java')).toString()
             .replace('${VERSION}', conf.version)
@@ -59,8 +127,10 @@ async function compileJava() {
         if (argv[2] === 'debug') args.push('-g');
         args.push('-d', 'dst/classes', 'Metadata.java');
     
+        console.log('Compiling java project...');
         for await (const path of find('src', undefined, v => v.endsWith('.java') && !v.endsWith('Metadata.java'))) args.push(path);
-        await run(conf.javahome + 'javac', ...args);
+        await run(false, conf.javahome + 'javac', ...args);
+        console.log('Compiled java project!');
     }
     finally {
         await fs.rm('Metadata.java');
@@ -69,13 +139,35 @@ async function compileJava() {
 
 (async () => {
     try {
-        try { await fs.rm('dst', { recursive: true }); } catch {}
-        await copy('src', 'dst/classes', v => !v.endsWith('.java'));
-        await compileJava();
-        await run('jar', '-c', '-f', 'dst/jscript.jar', '-e', 'me.topchetoeu.jscript.Main', '-C', 'dst/classes', '.');
+        if (argv[2] === 'init-ts') {
+            await downloadTypescript('src/assets/js/ts.js');
+        }
+        else {
+            const conf = {
+                name: "java-jscript",
+                author: "TopchetoEU",
+                javahome: "",
+                version: argv[3]
+            };
+
+            if (conf.version.startsWith('refs/tags/')) conf.version = conf.version.substring(10);
+            if (conf.version.startsWith('v')) conf.version = conf.version.substring(1);
+
+            try { await fs.rm('dst', { recursive: true }); } catch {}
+
+            await Promise.all([
+                downloadTypescript('dst/classes/assets/js/ts.js'),
+                copy('src', 'dst/classes', v => !v.endsWith('.java')),
+                compileJava(conf),
+            ]);
+
+            await run(true, 'jar', '-c', '-f', 'dst/jscript.jar', '-e', 'me.topchetoeu.jscript.Main', '-C', 'dst/classes', '.');
+            console.log('Done!');
+        }
     }
     catch (e) {
         if (argv[2] === 'debug') throw e;
-        else console.log(e.toString());
+        console.log(e.toString());
+        exit(-1);
     }
 })();

src/assets/js/bootstrap.js

@@ -0,0 +1,113 @@
+(function (ts, env, libs) {
+    var src = '', version = 0;
+    var lib = libs.concat([
+        'declare function exit(): never;',
+        'declare function go(): any;',
+        'declare function getTsDeclarations(): string[];'
+    ]).join('');
+    var libSnapshot = ts.ScriptSnapshot.fromString(lib);
+    var environments = {};
+    var declSnapshots = [];
+
+    var settings = {
+        outDir: "/out",
+        declarationDir: "/out",
+        target: ts.ScriptTarget.ES5,
+        lib: [ ],
+        module: ts.ModuleKind.None,
+        declaration: true,
+        stripInternal: true,
+        downlevelIteration: true,
+        forceConsistentCasingInFileNames: true,
+        experimentalDecorators: true,
+        strict: true,
+        sourceMap: true,
+    };
+
+    var reg = ts.createDocumentRegistry();
+    var service = ts.createLanguageService({
+        getCurrentDirectory: function() { return "/"; },
+        getDefaultLibFileName: function() { return "/lib.d.ts"; },
+        getScriptFileNames: function() {
+            var res = [ "/src.ts", "/lib.d.ts" ];
+            for (var i = 0; i < declSnapshots.length; i++) res.push("/glob." + (i + 1) + ".d.ts");
+            return res;
+        },
+        getCompilationSettings: function () { return settings; },
+        fileExists: function(filename) { return filename === "/lib.d.ts" || filename === "/src.ts" || filename === "/glob.d.ts"; },
+
+        getScriptSnapshot: function(filename) {
+            if (filename === "/lib.d.ts") return libSnapshot;
+            if (filename === "/src.ts") return ts.ScriptSnapshot.fromString(src);
+
+            var index = /\/glob\.(\d+)\.d\.ts/g.exec(filename);
+            if (index && index[1] && (index = Number(index[1])) && index > 0 && index <= declSnapshots.length) {
+                return declSnapshots[index - 1];
+            }
+
+            throw new Error("File '" + filename + "' doesn't exist.");
+        },
+        getScriptVersion: function (filename) {
+            if (filename === "/lib.d.ts" || filename.startsWith("/glob.")) return 0;
+            else return version;
+        },
+    }, reg);
+
+    service.getEmitOutput("/lib.d.ts");
+    log("Loaded libraries!");
+
+    var oldCompile = env.compile;
+
+    function compile(code, filename, env) {
+        src = code;
+        version++;
+
+        if (!environments[env.id]) environments[env.id] = []
+        var decls = declSnapshots = environments[env.id];
+        var emit = service.getEmitOutput("/src.ts");
+
+        var diagnostics = []
+            .concat(service.getCompilerOptionsDiagnostics())
+            .concat(service.getSyntacticDiagnostics("/src.ts"))
+            .concat(service.getSemanticDiagnostics("/src.ts"))
+            .map(function (diagnostic) {
+                var message = ts.flattenDiagnosticMessageText(diagnostic.messageText, "\n");
+                if (diagnostic.file) {
+                    var pos = diagnostic.file.getLineAndCharacterOfPosition(diagnostic.start);
+                    var file = diagnostic.file.fileName.substring(1);
+                    if (file === "src.ts") file = filename;
+                    return file + ":" + (pos.line + 1) + ":" + (pos.character + 1) + ": " + message;
+                }
+                else return message;
+            });
+
+        if (diagnostics.length > 0) {
+            throw new SyntaxError(diagnostics.join("\n"));
+        }
+
+        var map = JSON.parse(emit.outputFiles[0].text);
+        var result = emit.outputFiles[1].text;
+        var declaration = emit.outputFiles[2].text;
+
+        var compiled = oldCompile(result, filename, env);
+
+        return {
+            function: function () {
+                var val = compiled.function.apply(this, arguments);
+                if (declaration !== '') decls.push(ts.ScriptSnapshot.fromString(declaration));
+                return val;
+            },
+            breakpoints: compiled.breakpoints,
+            mapChain: compiled.mapChain.concat(map.mappings),
+        };
+    }
+
+    function apply(env) {
+        env.compile = compile;
+        env.global.getTsDeclarations = function() {
+            return environments[env.id];
+        }
+    }
+
+    apply(env);
+})(arguments[0], arguments[1], arguments[2]);

src/assets/js/lib.d.ts

@@ -19,12 +19,7 @@ type Extract<T, U> = T extends U ? T : never;
 type Record<KeyT extends string | number | symbol, ValT> = { [x in KeyT]: ValT }
 type ReplaceFunc = (match: string, ...args: any[]) => string;
 
-type PromiseFulfillFunc<T> = (val: T) => void;
-type PromiseThenFunc<T, NextT> = (val: T) => NextT;
-type PromiseRejectFunc = (err: unknown) => void;
-type PromiseFunc<T> = (resolve: PromiseFulfillFunc<T>, reject: PromiseRejectFunc) => void;
-
-type PromiseResult<T> ={ type: 'fulfilled'; value: T; } | { type: 'rejected'; reason: any; }
+type PromiseResult<T> = { type: 'fulfilled'; value: T; } | { type: 'rejected'; reason: any; }
 
 // wippidy-wine, this code is now mine :D
 type Awaited<T> =
@@ -46,8 +41,7 @@ type IteratorReturnResult<TReturn> =
 type IteratorResult<T, TReturn = any> = IteratorYieldResult<T> | IteratorReturnResult<TReturn>;
 
 interface Thenable<T> {
-    then<NextT>(onFulfilled: PromiseThenFunc<T, NextT>, onRejected?: PromiseRejectFunc): Promise<Awaited<NextT>>;
-    then(onFulfilled: undefined, onRejected?: PromiseRejectFunc): Promise<T>;
+    then<NextT = void>(onFulfilled?: (val: T) => NextT, onRejected?: (err: any) => NextT): Promise<Awaited<NextT>>;
 }
 
 interface RegExpResultIndices extends Array<[number, number]> {
@@ -111,7 +105,7 @@ interface AsyncIterableIterator<T> extends AsyncIterator<T> {
     [Symbol.asyncIterator](): AsyncIterableIterator<T>;
 }
 
-interface Generator<T = unknown, TReturn = unknown, TNext = unknown> extends Iterator<T, TReturn, TNext> {
+interface Generator<T = unknown, TReturn = void, TNext = unknown> extends Iterator<T, TReturn, TNext> {
     [Symbol.iterator](): Generator<T, TReturn, TNext>;
     return(value: TReturn): IteratorResult<T, TReturn>;
     throw(e: any): IteratorResult<T, TReturn>;
@@ -124,7 +118,7 @@ interface GeneratorFunction {
     readonly prototype: Generator;
 }
 
-interface AsyncGenerator<T = unknown, TReturn = unknown, TNext = unknown> extends AsyncIterator<T, TReturn, TNext> {
+interface AsyncGenerator<T = unknown, TReturn = void, TNext = unknown> extends AsyncIterator<T, TReturn, TNext> {
     return(value: TReturn | Thenable<TReturn>): Promise<IteratorResult<T, TReturn>>;
     throw(e: any): Promise<IteratorResult<T, TReturn>>;
     [Symbol.asyncIterator](): AsyncGenerator<T, TReturn, TNext>;
@@ -464,14 +458,19 @@ interface SymbolConstructor {
     readonly asyncIterator: unique symbol;
 }
 
+
 interface Promise<T> extends Thenable<T> {
-    catch(func: PromiseRejectFunc): Promise<T>;
+    catch<ResT = void>(func: (err: unknown) => ResT): Promise<ResT>;
     finally(func: () => void): Promise<T>;
+    constructor: PromiseConstructor;
 }
-interface PromiseConstructor {
+interface PromiseConstructorLike {
+    new <T>(func: (res: (val: T) => void, rej: (err: unknown) => void) => void): Thenable<Awaited<T>>;
+}
+interface PromiseConstructor extends PromiseConstructorLike {
     prototype: Promise<any>;
 
-    new <T>(func: PromiseFunc<T>): Promise<Awaited<T>>;
+    new <T>(func: (res: (val: T) => void, rej: (err: unknown) => void) => void): Promise<Awaited<T>>;
     resolve<T>(val: T): Promise<Awaited<T>>;
     reject(val: any): Promise<never>;
 
@@ -482,6 +481,39 @@ interface PromiseConstructor {
     allSettled<T extends any[]>(...promises: T): Promise<[...{ [P in keyof T]: PromiseResult<Awaited<T[P]>>}]>;
 }
 
+interface FileStat {
+    type: 'file' | 'folder';
+    mode: 'r' | 'rw';
+}
+interface File {
+    readonly pointer: Promise<number>;
+    readonly length: Promise<number>;
+
+    read(n: number): Promise<number[]>;
+    write(buff: number[]): Promise<void>;
+    close(): Promise<void>;
+    seek(offset: number, whence: number): Promise<void>;
+}
+interface Filesystem {
+    readonly SEEK_SET: 0;
+    readonly SEEK_CUR: 1;
+    readonly SEEK_END: 2;
+
+    open(path: string, mode: 'r' | 'rw'): Promise<File>;
+    ls(path: string): AsyncIterableIterator<string>;
+    mkdir(path: string): Promise<void>;
+    mkfile(path: string): Promise<void>;
+    rm(path: string, recursive?: boolean): Promise<void>;
+    stat(path: string): Promise<FileStat>;
+    exists(path: string): Promise<boolean>;
+    normalize(...paths: string[]): string;
+}
+
+interface Encoding {
+    encode(val: string): number[];
+    decode(val: number[]): string;
+}
+
 declare var String: StringConstructor;
 //@ts-ignore
 declare const arguments: IArguments;
@@ -498,6 +530,7 @@ declare var parseInt: typeof Number.parseInt;
 declare var parseFloat: typeof Number.parseFloat;
 
 declare function log(...vals: any[]): void;
+declare function require(name: string): any;
 
 declare var Array: ArrayConstructor;
 declare var Boolean: BooleanConstructor;
@@ -508,11 +541,14 @@ declare var Object: ObjectConstructor;
 declare var Symbol: SymbolConstructor;
 declare var Promise: PromiseConstructor;
 declare var Math: MathObject;
+declare var Encoding: Encoding;
+declare var Filesystem: Filesystem;
 
 declare var Error: ErrorConstructor;
 declare var RangeError: RangeErrorConstructor;
 declare var TypeError: TypeErrorConstructor;
 declare var SyntaxError: SyntaxErrorConstructor;
+declare var self: typeof globalThis;
 
 declare class Map<KeyT, ValueT> {
     public [Symbol.iterator](): IterableIterator<[KeyT, ValueT]>;
@@ -530,7 +566,7 @@ declare class Map<KeyT, ValueT> {
 
     public get size(): number;
 
-    public forEach(func: (key: KeyT, val: ValueT, map: Map<KeyT, ValueT>) => void, thisArg?: any): void;
+    public forEach(func: (val: ValueT, key: KeyT, map: Map<KeyT, ValueT>) => void, thisArg?: any): void;
 
     public constructor();
 }
@@ -549,7 +585,7 @@ declare class Set<T> {
 
     public get size(): number;
 
-    public forEach(func: (key: T, set: Set<T>) => void, thisArg?: any): void;
+    public forEach(func: (key: T, value: T, set: Set<T>) => void, thisArg?: any): void;
 
     public constructor();
 }

src/me/topchetoeu/jscript/Buffer.java

@@ -0,0 +1,53 @@
+package me.topchetoeu.jscript;
+
+public class Buffer {
+    private byte[] data;
+    private int length;
+
+    public void write(int i, byte[] val) {
+        if (i + val.length > data.length) {
+            var newCap = i + val.length + 1;
+            if (newCap < data.length * 2) newCap = data.length * 2;
+
+            var tmp = new byte[newCap];
+            System.arraycopy(this.data, 0, tmp, 0, length);
+            this.data = tmp;
+        }
+
+        System.arraycopy(val, 0, data, i, val.length);
+        if (i + val.length > length) length = i + val.length;
+    }
+    public int read(int i, byte[] buff) {
+        int n = buff.length;
+        if (i + n > length) n = length - i;
+        System.arraycopy(data, i, buff, 0, n);
+        return n;
+    }
+
+    public void append(byte b) {
+        write(length, new byte[] { b });
+    }
+
+    public byte[] data() {
+        var res = new byte[length];
+        System.arraycopy(this.data, 0, res, 0, length);
+        return res;
+    }
+    public int length() {
+        return length;
+    }
+
+    public Buffer(byte[] data) {
+        this.data = new byte[data.length];
+        this.length = data.length;
+        System.arraycopy(data, 0, this.data, 0, data.length);
+    }
+    public Buffer(int capacity) {
+        this.data = new byte[capacity];
+        this.length = 0;
+    }
+    public Buffer() {
+        this.data = new byte[128];
+        this.length = 0;
+    }
+}

src/me/topchetoeu/jscript/Filename.java

@@ -1,6 +1,7 @@
 package me.topchetoeu.jscript;
 
 import java.io.File;
+import java.nio.file.Path;
 
 public class Filename {
     public final String protocol;
@@ -40,13 +41,25 @@ public class Filename {
         return true;
     }
 
-    public static Filename fromFile(File file) {
-        return new Filename("file", file.getAbsolutePath());
-    }
+
 
 
     public Filename(String protocol, String path) {
+        path = path.trim();
+        protocol = protocol.trim();
         this.protocol = protocol;
         this.path = path;
     }
+
+    public static Filename parse(String val) {
+        var i = val.indexOf("://");
+        if (i >= 0) return new Filename(val.substring(0, i).trim(), val.substring(i + 3).trim());
+        else return new Filename("file", val.trim());
+    }
+    public static Path normalize(String path) {
+        return Path.of(Path.of("/" + path.trim().replace("\\", "/")).normalize().toString().substring(1));
+    }
+    public static Filename fromFile(File file) {
+        return new Filename("file", file.getAbsolutePath());
+    }
 }

src/me/topchetoeu/jscript/Location.java

@@ -1,7 +1,7 @@
 package me.topchetoeu.jscript;
 
 public class Location implements Comparable<Location> {
-    public static final Location INTERNAL = new Location(0, 0, new Filename("jscript", "internal"));
+    public static final Location INTERNAL = new Location(0, 0, new Filename("jscript", "native"));
     private int line;
     private int start;
     private Filename filename;
@@ -71,4 +71,23 @@ public class Location implements Comparable<Location> {
         this.start = start;
         this.filename = filename;
     }
+
+    public static Location parse(String raw) {
+        int i0 = -1, i1 = -1;
+        for (var i = raw.length() - 1; i >= 0; i--) {
+            if (raw.charAt(i) == ':') {
+                if (i1 == -1) i1 = i;
+                else if (i0 == -1) {
+                    i0 = i;
+                    break;
+                }
+            }
+        }
+
+        return new Location(
+            Integer.parseInt(raw.substring(i0 + 1, i1)),
+            Integer.parseInt(raw.substring(i1 + 1)),
+            Filename.parse(raw.substring(0, i0))
+        );
+    }
 }

src/me/topchetoeu/jscript/Main.java

@@ -1,107 +1,172 @@
-package me.topchetoeu.jscript;
-
-import java.io.IOException;
-import java.net.InetSocketAddress;
-import java.nio.file.Files;
-import java.nio.file.Path;
-
-import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Engine;
-import me.topchetoeu.jscript.engine.Environment;
-import me.topchetoeu.jscript.engine.debug.DebugServer;
-import me.topchetoeu.jscript.engine.debug.SimpleDebugger;
-import me.topchetoeu.jscript.engine.values.NativeFunction;
-import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.events.Observer;
-import me.topchetoeu.jscript.exceptions.EngineException;
-import me.topchetoeu.jscript.exceptions.InterruptException;
-import me.topchetoeu.jscript.exceptions.SyntaxException;
-import me.topchetoeu.jscript.exceptions.UncheckedException;
-import me.topchetoeu.jscript.lib.Internals;
-
-public class Main {
-    static Thread engineTask, debugTask;
-    static Engine engine;
-    static Environment env;
-    static int j = 0;
-
-    private static Observer<Object> valuePrinter = new Observer<Object>() {
-        public void next(Object data) {
-            Values.printValue(null, data);
-            System.out.println();
-        }
-
-        public void error(RuntimeException err) {
-            Values.printError(err, null);
-        }
-
-        @Override
-        public void finish() {
-            engineTask.interrupt();
-        }
-    };
-
-    public static void main(String args[]) {
-        System.out.println(String.format("Running %s v%s by %s", Metadata.NAME, Metadata.VERSION, Metadata.AUTHOR));
-        engine = new Engine();
-
-        env = new Environment(null, null, null);
-        var exited = new boolean[1];
-        var server = new DebugServer();
-        server.targets.put("target", (ws, req) -> SimpleDebugger.get(ws, engine));
-
-        engine.pushMsg(false, null, new NativeFunction((ctx, thisArg, _a) -> {
-            new Internals().apply(env);
-
-            env.global.define("exit", _ctx -> {
-                exited[0] = true;
-                throw new InterruptException();
-            });
-            env.global.define("go", _ctx -> {
-                try {
-                    var f = Path.of("do.js");
-                    var func = _ctx.compile(new Filename("do", "do/" + j++ + ".js"), new String(Files.readAllBytes(f)));
-                    return func.call(_ctx);
-                }
-                catch (IOException e) {
-                    throw new EngineException("Couldn't open do.js");
-                }
-            });
-
-            return null;
-        }), null);
-
-        engineTask = engine.start();
-        debugTask = server.start(new InetSocketAddress("127.0.0.1", 9229), true);
-
-        var reader = new Thread(() -> {
-            try {
-                for (var i = 0; ; i++) {
-                    try {
-                        var raw = Reading.read();
-
-                        if (raw == null) break;
-                        valuePrinter.next(engine.pushMsg(false, new Context(engine).pushEnv(env), new Filename("jscript", "repl/" + i + ".js"), raw, null).await());
-                    }
-                    catch (EngineException e) { Values.printError(e, ""); }
-                }
-            }
-            catch (IOException e) { return; }
-            catch (SyntaxException ex) {
-                if (exited[0]) return;
-                System.out.println("Syntax error:" + ex.msg);
-            }
-            catch (RuntimeException ex) {
-                if (!exited[0]) {
-                    System.out.println("Internal error ocurred:");
-                    ex.printStackTrace();
-                }
-            }
-            catch (Throwable e) { throw new UncheckedException(e); }
-            if (exited[0]) debugTask.interrupt();
-        });
-        reader.setDaemon(true);
-        reader.setName("STD Reader");
-        reader.start();
-    }
-}
+package me.topchetoeu.jscript;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.Engine;
+import me.topchetoeu.jscript.engine.Environment;
+import me.topchetoeu.jscript.engine.debug.DebugContext;
+import me.topchetoeu.jscript.engine.debug.DebugServer;
+import me.topchetoeu.jscript.engine.debug.SimpleDebugger;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
+import me.topchetoeu.jscript.engine.values.NativeFunction;
+import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.exceptions.EngineException;
+import me.topchetoeu.jscript.exceptions.InterruptException;
+import me.topchetoeu.jscript.exceptions.SyntaxException;
+import me.topchetoeu.jscript.filesystem.Filesystem;
+import me.topchetoeu.jscript.filesystem.MemoryFilesystem;
+import me.topchetoeu.jscript.filesystem.Mode;
+import me.topchetoeu.jscript.filesystem.PhysicalFilesystem;
+import me.topchetoeu.jscript.filesystem.RootFilesystem;
+import me.topchetoeu.jscript.lib.EnvironmentLib;
+import me.topchetoeu.jscript.lib.Internals;
+import me.topchetoeu.jscript.modules.ModuleRepo;
+import me.topchetoeu.jscript.permissions.PermissionsManager;
+import me.topchetoeu.jscript.permissions.PermissionsProvider;
+
+public class Main {
+    static Thread engineTask, debugTask;
+    static Engine engine = new Engine();
+    static DebugServer debugServer = new DebugServer();
+    static Environment environment = new Environment();
+
+    static int j = 0;
+    static boolean exited = false;
+    static String[] args;
+
+    private static void reader() {
+        try {
+            for (var arg : args) {
+                try {
+                    if (arg.equals("--ts")) initTypescript();
+                    else {
+                        var file = Path.of(arg);
+                        var raw = Files.readString(file);
+                        var res = engine.pushMsg(
+                            false, environment,
+                            Filename.fromFile(file.toFile()),
+                            raw, null
+                        ).await();
+                        Values.printValue(null, res);
+                        System.out.println();
+                    }
+                }
+                catch (EngineException e) { Values.printError(e, null); }
+            }
+            for (var i = 0; ; i++) {
+                try {
+                    var raw = Reading.readline();
+
+                    if (raw == null) break;
+                    var res = engine.pushMsg(
+                        false, environment,
+                        new Filename("jscript", "repl/" + i + ".js"),
+                        raw, null
+                    ).await();
+                    Values.printValue(null, res);
+                    System.out.println();
+                }
+                catch (EngineException e) { Values.printError(e, null); }
+                catch (SyntaxException e) { Values.printError(e, null); }
+            }
+        }
+        catch (IOException e) {
+            System.out.println(e.toString());
+            exited = true;
+        }
+        catch (RuntimeException ex) {
+            if (!exited) {
+                System.out.println("Internal error ocurred:");
+                ex.printStackTrace();
+            }
+        }
+        if (exited) {
+            debugTask.interrupt();
+            engineTask.interrupt();
+        }
+    }
+
+    private static void initEnv() {
+        environment = Internals.apply(environment);
+
+        environment.global.define(false, new NativeFunction("exit", args -> {
+            exited = true;
+            throw new InterruptException();
+        }));
+        environment.global.define(false, new NativeFunction("go", args -> {
+            try {
+                var f = Path.of("do.js");
+                var func = args.ctx.compile(new Filename("do", "do/" + j++ + ".js"), new String(Files.readAllBytes(f)));
+                return func.call(args.ctx);
+            }
+            catch (IOException e) {
+                throw new EngineException("Couldn't open do.js");
+            }
+        }));
+
+        var fs = new RootFilesystem(PermissionsProvider.get(environment));
+        fs.protocols.put("temp", new MemoryFilesystem(Mode.READ_WRITE));
+        fs.protocols.put("file", new PhysicalFilesystem("."));
+
+        environment.add(PermissionsProvider.ENV_KEY, PermissionsManager.ALL_PERMS);
+        environment.add(Filesystem.ENV_KEY, fs);
+        environment.add(ModuleRepo.ENV_KEY, ModuleRepo.ofFilesystem(fs));
+    }
+    private static void initEngine() {
+        var ctx = new DebugContext();
+        engine.add(DebugContext.ENV_KEY, ctx);
+
+        debugServer.targets.put("target", (ws, req) -> new SimpleDebugger(ws).attach(ctx));
+        engineTask = engine.start();
+        debugTask = debugServer.start(new InetSocketAddress("127.0.0.1", 9229), true);
+    }
+    private static void initTypescript() throws IOException {
+        var tsEnv = Internals.apply(new Environment());
+        var bsEnv = Internals.apply(new Environment());
+
+        try {
+            tsEnv.global.define(null, "module", false, new ObjectValue());
+
+            engine.pushMsg(
+                false, tsEnv,
+                new Filename("jscript", "ts.js"),
+                Reading.resourceToString("assets/js/ts.js"), null
+            ).await();
+            System.out.println("Loaded typescript!");
+
+            var typescript = tsEnv.global.get(new Context(engine, bsEnv), "ts");
+            var libs = new ArrayValue(null, Reading.resourceToString("assets/js/lib.d.ts"));
+
+            engine.pushMsg(
+                false, bsEnv,
+                new Filename("jscript", "bootstrap.js"), Reading.resourceToString("assets/js/bootstrap.js"), null,
+                typescript, new EnvironmentLib(environment), libs
+            ).await();
+        }
+        catch (EngineException e) {
+            Values.printError(e, "(while initializing TS)");
+        }
+
+        bsEnv.add(Environment.HIDE_STACK, true);
+        tsEnv.add(Environment.HIDE_STACK, true);
+    }
+
+    public static void main(String args[]) {
+        System.out.println(String.format("Running %s v%s by %s", Metadata.name(), Metadata.version(), Metadata.author()));
+
+        Main.args = args;
+        var reader = new Thread(Main::reader);
+
+        initEnv();
+        initEngine();
+
+        reader.setDaemon(true);
+        reader.setName("STD Reader");
+        reader.start();
+    }
+}

src/me/topchetoeu/jscript/MessageReceiver.java

@@ -1,6 +0,0 @@
-package me.topchetoeu.jscript;
-
-public interface MessageReceiver {
-    void sendMessage(String msg);
-    void sendError(String msg);
-}

src/me/topchetoeu/jscript/Metadata.java

@@ -1,7 +1,20 @@
 package me.topchetoeu.jscript;
 
 public class Metadata {
-    public static final String VERSION = "${VERSION}";
-    public static final String AUTHOR = "${AUTHOR}";
-    public static final String NAME = "${NAME}";
+    private static final String VERSION = "${VERSION}";
+    private static final String AUTHOR = "${AUTHOR}";
+    private static final String NAME = "${NAME}";
+
+    public static String version() {
+        if (VERSION.equals("$" + "{VERSION}")) return "1337-devel";
+        else return VERSION;
+    }
+    public static String author() {
+        if (AUTHOR.equals("$" + "{AUTHOR}")) return "anonymous";
+        else return AUTHOR;
+    }
+    public static String name() {
+        if (NAME.equals("$" + "{NAME}")) return "some-product";
+        else return NAME;
+    }
 }

src/me/topchetoeu/jscript/Reading.java

@@ -4,33 +4,30 @@ import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-
-import me.topchetoeu.jscript.exceptions.UncheckedException;
+import java.io.UncheckedIOException;
 
 public class Reading {
     private static final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
 
-    public static synchronized String read() throws IOException {
+    public static synchronized String readline() throws IOException {
         return reader.readLine();
     }
 
+    /**
+     * Reads the given stream to a string
+     * @param in 
+     * @return
+     */
     public static String streamToString(InputStream in) {
         try {
-            StringBuilder out = new StringBuilder();
-            BufferedReader br = new BufferedReader(new InputStreamReader(in));
-
-            for(var line = br.readLine(); line != null; line = br.readLine()) {
-                out.append(line).append('\n');
-            }
-
-            br.close();
-            return out.toString();
+            return new String(in.readAllBytes());
         }
-        catch (Throwable e) { throw new UncheckedException(e); }
+        catch (IOException e) { throw new UncheckedIOException(e); }
+    }
+    public static InputStream resourceToStream(String name) {
+        return Reading.class.getResourceAsStream("/" + name);
     }
     public static String resourceToString(String name) {
-        var str = Main.class.getResourceAsStream("/me/topchetoeu/jscript/" + name);
-        if (str == null) return null;
-        return streamToString(str);
+        return streamToString(resourceToStream(name));
     }
 }

src/me/topchetoeu/jscript/ResultRunnable.java

@@ -0,0 +1,5 @@
+package me.topchetoeu.jscript;
+
+public interface ResultRunnable<T> {
+    T run();
+}

src/me/topchetoeu/jscript/compilation/CalculateResult.java

@@ -0,0 +1,21 @@
+package me.topchetoeu.jscript.compilation;
+
+import me.topchetoeu.jscript.engine.values.Values;
+
+public final class CalculateResult {
+    public final boolean exists;
+    public final Object value;
+
+    public final boolean isTruthy() {
+        return exists && Values.toBoolean(value);
+    }
+
+    public CalculateResult(Object value) {
+        this.exists = true;
+        this.value = value;
+    }
+    public CalculateResult() {
+        this.exists = false;
+        this.value = null;
+    }
+}

src/me/topchetoeu/jscript/compilation/CompileTarget.java

@@ -1,38 +1,66 @@
-package me.topchetoeu.jscript.compilation;
-
-import java.util.Map;
-import java.util.TreeSet;
-import java.util.Vector;
-
-import me.topchetoeu.jscript.Location;
-
-public class CompileTarget {
-    public final Vector<Instruction> target = new Vector<>();
-    public final Map<Long, FunctionBody> functions;
-    public final TreeSet<Location> breakpoints;
-
-    public Instruction add(Instruction instr) {
-        target.add(instr);
-        return instr;
-    }
-    public Instruction set(int i, Instruction instr) {
-        return target.set(i, instr);
-    }
-    public void setDebug(int i) {
-        breakpoints.add(target.get(i).location);
-    }
-    public void setDebug() {
-        setDebug(target.size() - 1);
-    }
-    public Instruction get(int i) {
-        return target.get(i);
-    }
-    public int size() { return target.size(); }
-
-    public Instruction[] array() { return target.toArray(Instruction[]::new); }
-
-    public CompileTarget(Map<Long, FunctionBody> functions, TreeSet<Location> breakpoints) {
-        this.functions = functions;
-        this.breakpoints = breakpoints;
-    }
-}
+package me.topchetoeu.jscript.compilation;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.TreeSet;
+import java.util.Vector;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.engine.Environment;
+import me.topchetoeu.jscript.engine.values.CodeFunction;
+
+public class CompileTarget {
+    public final Vector<Instruction> target = new Vector<>();
+    public final Map<Long, FunctionBody> functions;
+    public final TreeSet<Location> breakpoints;
+    private final HashMap<Location, Instruction> bpToInstr = new HashMap<>();
+
+    public Instruction add(Instruction instr) {
+        target.add(instr);
+        return instr;
+    }
+    public Instruction set(int i, Instruction instr) {
+        return target.set(i, instr);
+    }
+    public void setDebug(int i, BreakpointType type) {
+        var instr = target.get(i);
+        instr.breakpoint = type;
+
+        if (type == BreakpointType.NONE) {
+            breakpoints.remove(target.get(i).location);
+            bpToInstr.remove(instr.location, instr);
+        }
+        else {
+            breakpoints.add(target.get(i).location);
+
+            var old = bpToInstr.put(instr.location, instr);
+            if (old != null) old.breakpoint = BreakpointType.NONE;
+        }
+    }
+    public void setDebug(BreakpointType type) {
+        setDebug(target.size() - 1, type);
+    }
+    public Instruction get(int i) {
+        return target.get(i);
+    }
+    public int size() { return target.size(); }
+    public Location lastLoc(Location fallback) {
+        if (target.size() == 0) return fallback;
+        else return target.get(target.size() - 1).location;
+    }
+
+    public Instruction[] array() { return target.toArray(Instruction[]::new); }
+
+    public FunctionBody body() {
+        return functions.get(0l);
+    }
+    public CodeFunction func(Environment env) {
+        return new CodeFunction(env, "", body());
+    }
+
+    public CompileTarget(Map<Long, FunctionBody> functions, TreeSet<Location> breakpoints) {
+        this.functions = functions;
+        this.breakpoints = breakpoints;
+    }
+}

src/me/topchetoeu/jscript/compilation/CompoundStatement.java

@@ -1,68 +1,54 @@
 package me.topchetoeu.jscript.compilation;
 
+import java.util.List;
 import java.util.Vector;
 
 import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.control.ContinueStatement;
-import me.topchetoeu.jscript.compilation.control.ReturnStatement;
-import me.topchetoeu.jscript.compilation.control.ThrowStatement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
 import me.topchetoeu.jscript.compilation.values.FunctionStatement;
 import me.topchetoeu.jscript.engine.scope.ScopeRecord;
 
 public class CompoundStatement extends Statement {
     public final Statement[] statements;
+    public final boolean separateFuncs;
     public Location end;
 
+    @Override public boolean pure() {
+        for (var stm : statements) {
+            if (!stm.pure()) return false;
+        }
+
+        return true;
+    }
+
     @Override
     public void declare(ScopeRecord varsScope) {
-        for (var stm : statements) {
-            stm.declare(varsScope);
-        }
+        for (var stm : statements) stm.declare(varsScope);
     }
 
     @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        for (var stm : statements) {
-            if (stm instanceof FunctionStatement) {
-                int start = target.size();
-                ((FunctionStatement)stm).compile(target, scope, null, true);
-                target.setDebug(start);
-                target.add(Instruction.discard());
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute, BreakpointType type) {
+        List<Statement> statements = new Vector<Statement>();
+        if (separateFuncs) for (var stm : this.statements) {
+            if (stm instanceof FunctionStatement && ((FunctionStatement)stm).statement) {
+                stm.compile(target, scope, false);
             }
+            else statements.add(stm);
+        }
+        else statements = List.of(this.statements);
+
+        var polluted = false;
+
+        for (var i = 0; i < statements.size(); i++) {
+            var stm = statements.get(i);
+
+            if (i != statements.size() - 1) stm.compile(target, scope, false, BreakpointType.STEP_OVER);
+            else stm.compile(target, scope, polluted = pollute, BreakpointType.STEP_OVER);
         }
 
-        for (var i = 0; i < statements.length; i++) {
-            var stm = statements[i];
-
-            if (stm instanceof FunctionStatement) continue;
-            if (i != statements.length - 1) stm.compileWithDebug(target, scope, false);
-            else stm.compileWithDebug(target, scope, pollute);
+        if (!polluted && pollute) {
+            target.add(Instruction.loadValue(loc(), null));
         }
-
-        if (end != null) {
-            target.add(Instruction.nop().locate(end));
-            target.setDebug();
-        }
-    }
-
-    @Override
-    public Statement optimize() {
-        var res = new Vector<Statement>(statements.length);
-
-        for (var i = 0; i < statements.length; i++) {
-            var stm = statements[i].optimize();
-            if (i < statements.length - 1 && stm.pure()) continue;
-            res.add(stm);
-            if (
-                stm instanceof ContinueStatement ||
-                stm instanceof ReturnStatement ||
-                stm instanceof ThrowStatement ||
-                stm instanceof ContinueStatement
-            ) break;
-        }
-
-        if (res.size() == 1) return res.get(0);
-        else return new CompoundStatement(loc(), res.toArray(Statement[]::new));
     }
 
     public CompoundStatement setEnd(Location loc) {
@@ -70,8 +56,9 @@ public class CompoundStatement extends Statement {
         return this;
     }
 
-    public CompoundStatement(Location loc, Statement ...statements) {
+    public CompoundStatement(Location loc, boolean separateFuncs, Statement ...statements) {
         super(loc);
+        this.separateFuncs = separateFuncs;
         this.statements = statements;
     }
 }

src/me/topchetoeu/jscript/compilation/FunctionBody.java

@@ -3,13 +3,25 @@ package me.topchetoeu.jscript.compilation;
 public class FunctionBody {
     public final Instruction[] instructions;
     public final String[] captureNames, localNames;
+    public final int localsN, argsN;
 
-    public FunctionBody(Instruction[] instructions, String[] captureNames, String[] localNames) {
+    public FunctionBody(int localsN, int argsN, Instruction[] instructions, String[] captureNames, String[] localNames) {
+        this.argsN = argsN;
+        this.localsN = localsN;
         this.instructions = instructions;
         this.captureNames = captureNames;
         this.localNames = localNames;
     }
-    public FunctionBody(Instruction[] instructions) {
+    public FunctionBody(int localsN, int argsN, Instruction[] instructions) {
+        this.argsN = argsN;
+        this.localsN = localsN;
+        this.instructions = instructions;
+        this.captureNames = new String[0];
+        this.localNames = new String[0];
+    }
+    public FunctionBody(Instruction... instructions) {
+        this.argsN = 0;
+        this.localsN = 2;
         this.instructions = instructions;
         this.captureNames = new String[0];
         this.localNames = new String[0];

src/me/topchetoeu/jscript/compilation/Instruction.java

@@ -10,7 +10,8 @@ public class Instruction {
         THROW,
         THROW_SYNTAX,
         DELETE,
-        TRY,
+        TRY_START,
+        TRY_END,
         NOP,
 
         CALL,
@@ -33,7 +34,6 @@ public class Instruction {
         LOAD_REGEX,
 
         DUP,
-        MOVE,
 
         STORE_VAR,
         STORE_MEMBER,
@@ -45,51 +45,30 @@ public class Instruction {
 
         TYPEOF,
         OPERATION;
-        // TYPEOF,
-        // INSTANCEOF(true),
-        // IN(true),
+    }
+    public static enum BreakpointType {
+        NONE,
+        STEP_OVER,
+        STEP_IN;
 
-        // MULTIPLY(true),
-        // DIVIDE(true),
-        // MODULO(true),
-        // ADD(true),
-        // SUBTRACT(true),
-
-        // USHIFT_RIGHT(true),
-        // SHIFT_RIGHT(true),
-        // SHIFT_LEFT(true),
-
-        // GREATER(true),
-        // LESS(true),
-        // GREATER_EQUALS(true),
-        // LESS_EQUALS(true),
-        // LOOSE_EQUALS(true),
-        // LOOSE_NOT_EQUALS(true),
-        // EQUALS(true),
-        // NOT_EQUALS(true),
-
-        // AND(true),
-        // OR(true),
-        // XOR(true),
-
-        // NEG(true),
-        // POS(true),
-        // NOT(true),
-        // INVERSE(true);
-
-        // final boolean isOperation;
-
-        // private Type(boolean isOperation) {
-        //     this.isOperation = isOperation;
-        // }
-        // private Type() {
-        //     this(false);
-        // }
+        public boolean shouldStepIn() {
+            return this != NONE;
+        }
+        public boolean shouldStepOver() {
+            return this == STEP_OVER;
+        }
     }
 
     public final Type type;
     public final Object[] params;
     public Location location;
+    public BreakpointType breakpoint = BreakpointType.NONE;
+
+    public Instruction setDbgData(Instruction other) {
+        this.location = other.location;
+        this.breakpoint = other.breakpoint;
+        return this;
+    }
 
     public Instruction locate(Location loc) {
         this.location = loc;
@@ -129,26 +108,32 @@ public class Instruction {
         this.params = params;
     }
 
-    public static Instruction tryInstr(int n, int catchN, int finallyN) {
-        return new Instruction(null, Type.TRY, n, catchN, finallyN);
+    public static Instruction tryStart(Location loc, int catchStart, int finallyStart, int end) {
+        return new Instruction(loc, Type.TRY_START, catchStart, finallyStart, end);
     }
-    public static Instruction throwInstr() {
-        return new Instruction(null, Type.THROW);
+    public static Instruction tryEnd(Location loc) {
+        return new Instruction(loc, Type.TRY_END);
     }
-    public static Instruction throwSyntax(SyntaxException err) {
-        return new Instruction(null, Type.THROW_SYNTAX, err.getMessage());
+    public static Instruction throwInstr(Location loc) {
+        return new Instruction(loc, Type.THROW);
     }
-    public static Instruction delete() {
-        return new Instruction(null, Type.DELETE);
+    public static Instruction throwSyntax(Location loc, SyntaxException err) {
+        return new Instruction(loc, Type.THROW_SYNTAX, err.getMessage());
     }
-    public static Instruction ret() {
-        return new Instruction(null, Type.RETURN);
+    public static Instruction throwSyntax(Location loc, String err) {
+        return new Instruction(loc, Type.THROW_SYNTAX, err);
     }
-    public static Instruction debug() {
-        return new Instruction(null, Type.NOP, "debug");
+    public static Instruction delete(Location loc) {
+        return new Instruction(loc, Type.DELETE);
+    }
+    public static Instruction ret(Location loc) {
+        return new Instruction(loc, Type.RETURN);
+    }
+    public static Instruction debug(Location loc) {
+        return new Instruction(loc, Type.NOP, "debug");
     }
 
-    public static Instruction nop(Object ...params) {
+    public static Instruction nop(Location loc, Object ...params) {
         for (var param : params) {
             if (param instanceof String) continue;
             if (param instanceof Boolean) continue;
@@ -158,109 +143,104 @@ public class Instruction {
 
             throw new RuntimeException("NOP params may contain only strings, booleans, doubles, integers and nulls.");
         }
-        return new Instruction(null, Type.NOP, params);
+        return new Instruction(loc, Type.NOP, params);
     }
 
-    public static Instruction call(int argn) {
-        return new Instruction(null, Type.CALL, argn);
+    public static Instruction call(Location loc, int argn) {
+        return new Instruction(loc, Type.CALL, argn);
     }
-    public static Instruction callNew(int argn) {
-        return new Instruction(null, Type.CALL_NEW, argn);
+    public static Instruction callNew(Location loc, int argn) {
+        return new Instruction(loc, Type.CALL_NEW, argn);
     }
-    public static Instruction jmp(int offset) {
-        return new Instruction(null, Type.JMP, offset);
+    public static Instruction jmp(Location loc, int offset) {
+        return new Instruction(loc, Type.JMP, offset);
     }
-    public static Instruction jmpIf(int offset) {
-        return new Instruction(null, Type.JMP_IF, offset);
+    public static Instruction jmpIf(Location loc, int offset) {
+        return new Instruction(loc, Type.JMP_IF, offset);
     }
-    public static Instruction jmpIfNot(int offset) {
-        return new Instruction(null, Type.JMP_IFN, offset);
+    public static Instruction jmpIfNot(Location loc, int offset) {
+        return new Instruction(loc, Type.JMP_IFN, offset);
     }
 
-    public static Instruction loadValue(Object val) {
-        return new Instruction(null, Type.LOAD_VALUE, val);
+    public static Instruction loadValue(Location loc, Object val) {
+        return new Instruction(loc, Type.LOAD_VALUE, val);
     }
 
-    public static Instruction makeVar(String name) {
-        return new Instruction(null, Type.MAKE_VAR, name);
+    public static Instruction makeVar(Location loc, String name) {
+        return new Instruction(loc, Type.MAKE_VAR, name);
     }
-    public static Instruction loadVar(Object i) {
-        return new Instruction(null, Type.LOAD_VAR, i);
+    public static Instruction loadVar(Location loc, Object i) {
+        return new Instruction(loc, Type.LOAD_VAR, i);
     }
-    public static Instruction loadGlob() {
-        return new Instruction(null, Type.LOAD_GLOB);
+    public static Instruction loadGlob(Location loc) {
+        return new Instruction(loc, Type.LOAD_GLOB);
     }
-    public static Instruction loadMember() {
-        return new Instruction(null, Type.LOAD_MEMBER);
+    public static Instruction loadMember(Location loc) {
+        return new Instruction(loc, Type.LOAD_MEMBER);
     }
-    public static Instruction loadMember(Object key) {
+    public static Instruction loadMember(Location loc, Object key) {
         if (key instanceof Number) key = ((Number)key).doubleValue();
-        return new Instruction(null, Type.LOAD_VAL_MEMBER, key);
+        return new Instruction(loc, Type.LOAD_VAL_MEMBER, key);
     }
 
-    public static Instruction loadRegex(String pattern, String flags) {
-        return new Instruction(null, Type.LOAD_REGEX, pattern, flags);
+    public static Instruction loadRegex(Location loc, String pattern, String flags) {
+        return new Instruction(loc, Type.LOAD_REGEX, pattern, flags);
     }
-    public static Instruction loadFunc(long id, int varN, int len, int[] captures) {
-        var args = new Object[3 + captures.length];
+    public static Instruction loadFunc(Location loc, long id, int[] captures) {
+        var args = new Object[1 + captures.length];
         args[0] = id;
-        args[1] = varN;
-        args[2] = len;
-        for (var i = 0; i < captures.length; i++) args[i + 3] = captures[i];
-        return new Instruction(null, Type.LOAD_FUNC, args);
+        for (var i = 0; i < captures.length; i++) args[i + 1] = captures[i];
+        return new Instruction(loc, Type.LOAD_FUNC, args);
     }
-    public static Instruction loadObj() {
-        return new Instruction(null, Type.LOAD_OBJ);
+    public static Instruction loadObj(Location loc) {
+        return new Instruction(loc, Type.LOAD_OBJ);
     }
-    public static Instruction loadArr(int count) {
-        return new Instruction(null, Type.LOAD_ARR, count);
+    public static Instruction loadArr(Location loc, int count) {
+        return new Instruction(loc, Type.LOAD_ARR, count);
     }
-    public static Instruction dup() {
-        return new Instruction(null, Type.DUP, 0, 1);
+    public static Instruction dup(Location loc) {
+        return new Instruction(loc, Type.DUP, 1);
     }
-    public static Instruction dup(int count, int offset) {
-        return new Instruction(null, Type.DUP, offset, count);
-    }
-    public static Instruction move(int count, int offset) {
-        return new Instruction(null, Type.MOVE, offset, count);
+    public static Instruction dup(Location loc, int count) {
+        return new Instruction(loc, Type.DUP, count);
     }
 
-    public static Instruction storeSelfFunc(int i) {
-        return new Instruction(null, Type.STORE_SELF_FUNC, i);
+    public static Instruction storeSelfFunc(Location loc, int i) {
+        return new Instruction(loc, Type.STORE_SELF_FUNC, i);
     }
-    public static Instruction storeVar(Object i) {
-        return new Instruction(null, Type.STORE_VAR, i, false);
+    public static Instruction storeVar(Location loc, Object i) {
+        return new Instruction(loc, Type.STORE_VAR, i, false);
     }
-    public static Instruction storeVar(Object i, boolean keep) {
-        return new Instruction(null, Type.STORE_VAR, i, keep);
+    public static Instruction storeVar(Location loc, Object i, boolean keep) {
+        return new Instruction(loc, Type.STORE_VAR, i, keep);
     }
-    public static Instruction storeMember() {
-        return new Instruction(null, Type.STORE_MEMBER, false);
+    public static Instruction storeMember(Location loc) {
+        return new Instruction(loc, Type.STORE_MEMBER, false);
     }
-    public static Instruction storeMember(boolean keep) {
-        return new Instruction(null, Type.STORE_MEMBER, keep);
+    public static Instruction storeMember(Location loc, boolean keep) {
+        return new Instruction(loc, Type.STORE_MEMBER, keep);
     }
-    public static Instruction discard() {
-        return new Instruction(null, Type.DISCARD);
+    public static Instruction discard(Location loc) {
+        return new Instruction(loc, Type.DISCARD);
     }
 
-    public static Instruction typeof() {
-        return new Instruction(null, Type.TYPEOF);
+    public static Instruction typeof(Location loc) {
+        return new Instruction(loc, Type.TYPEOF);
     }
-    public static Instruction typeof(Object varName) {
-        return new Instruction(null, Type.TYPEOF, varName);
+    public static Instruction typeof(Location loc, Object varName) {
+        return new Instruction(loc, Type.TYPEOF, varName);
     }
 
-    public static Instruction keys() {
-        return new Instruction(null, Type.KEYS);
+    public static Instruction keys(Location loc, boolean forInFormat) {
+        return new Instruction(loc, Type.KEYS, forInFormat);
     }
 
-    public static Instruction defProp() {
-        return new Instruction(null, Type.DEF_PROP);
+    public static Instruction defProp(Location loc) {
+        return new Instruction(loc, Type.DEF_PROP);
     }
 
-    public static Instruction operation(Operation op) {
-        return new Instruction(null, Type.OPERATION, op);
+    public static Instruction operation(Location loc, Operation op) {
+        return new Instruction(loc, Type.OPERATION, op);
     }
 
     @Override

src/me/topchetoeu/jscript/compilation/Statement.java

@@ -1,20 +1,26 @@
 package me.topchetoeu.jscript.compilation;
 
 import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
 import me.topchetoeu.jscript.engine.scope.ScopeRecord;
 
 public abstract class Statement {
     private Location _loc;
 
     public boolean pure() { return false; }
-    public abstract void compile(CompileTarget target, ScopeRecord scope, boolean pollute);
     public void declare(ScopeRecord varsScope) { }
-    public Statement optimize() { return this; }
 
-    public void compileWithDebug(CompileTarget target, ScopeRecord scope, boolean pollute) {
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute, BreakpointType type) {
         int start = target.size();
         compile(target, scope, pollute);
-        if (target.size() != start) target.setDebug(start);
+
+        if (target.size() != start) {
+            target.get(start).locate(loc());
+            target.setDebug(start, type);
+        }
+    }
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        compile(target, scope, pollute, BreakpointType.NONE);
     }
 
     public Location loc() { return _loc; }

src/me/topchetoeu/jscript/compilation/ThrowSyntaxStatement.java

@@ -0,0 +1,18 @@
+package me.topchetoeu.jscript.compilation;
+
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+import me.topchetoeu.jscript.exceptions.SyntaxException;
+
+public class ThrowSyntaxStatement extends Statement {
+    public final String name;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        target.add(Instruction.throwSyntax(loc(), name));
+    }
+
+    public ThrowSyntaxStatement(SyntaxException e) {
+        super(e.loc);
+        this.name = e.msg;
+    }
+}

src/me/topchetoeu/jscript/compilation/VariableDeclareStatement.java

@@ -1,58 +1,52 @@
-package me.topchetoeu.jscript.compilation;
-
-import java.util.List;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.values.FunctionStatement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class VariableDeclareStatement extends Statement {
-    public static class Pair {
-        public final String name;
-        public final Statement value;
-        public final Location location;
-
-        public Pair(String name, Statement value, Location location) {
-            this.name = name;
-            this.value = value;
-            this.location = location;
-        }
-    }
-
-    public final List<Pair> values;
-
-    @Override
-    public void declare(ScopeRecord varsScope) {
-        for (var key : values) {
-            varsScope.define(key.name);
-        }
-    }
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        for (var entry : values) {
-            if (entry.name == null) continue;
-            var key = scope.getKey(entry.name);
-            int start = target.size();
-
-            if (key instanceof String) target.add(Instruction.makeVar((String)key).locate(entry.location));
-
-            if (entry.value instanceof FunctionStatement) {
-                ((FunctionStatement)entry.value).compile(target, scope, entry.name, false);
-                target.add(Instruction.storeVar(key).locate(entry.location));
-            }
-            else if (entry.value != null) {
-                entry.value.compile(target, scope, true);
-                target.add(Instruction.storeVar(key).locate(entry.location));
-            }
-
-            if (target.size() != start) target.setDebug(start);
-        }
-
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-
-    public VariableDeclareStatement(Location loc, List<Pair> values) {
-        super(loc);
-        this.values = values;
-    }
-}
+package me.topchetoeu.jscript.compilation;
+
+import java.util.List;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.compilation.values.FunctionStatement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class VariableDeclareStatement extends Statement {
+    public static class Pair {
+        public final String name;
+        public final Statement value;
+        public final Location location;
+
+        public Pair(String name, Statement value, Location location) {
+            this.name = name;
+            this.value = value;
+            this.location = location;
+        }
+    }
+
+    public final List<Pair> values;
+
+    @Override
+    public void declare(ScopeRecord varsScope) {
+        for (var key : values) {
+            varsScope.define(key.name);
+        }
+    }
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        for (var entry : values) {
+            if (entry.name == null) continue;
+            var key = scope.getKey(entry.name);
+
+            if (key instanceof String) target.add(Instruction.makeVar(entry.location, (String)key));
+
+            if (entry.value != null) {
+                FunctionStatement.compileWithName(entry.value, target, scope, true, entry.name, BreakpointType.STEP_OVER);
+                target.add(Instruction.storeVar(entry.location, key));
+            }
+        }
+
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+    }
+
+    public VariableDeclareStatement(Location loc, List<Pair> values) {
+        super(loc);
+        this.values = values;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/BreakStatement.java

@@ -1,22 +1,22 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class BreakStatement extends Statement {
-    public final String label;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        target.add(Instruction.nop("break", label).locate(loc()));
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-
-    public BreakStatement(Location loc, String label) {
-        super(loc);
-        this.label = label;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class BreakStatement extends Statement {
+    public final String label;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        target.add(Instruction.nop(loc(), "break", label));
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+    }
+
+    public BreakStatement(Location loc, String label) {
+        super(loc);
+        this.label = label;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/ContinueStatement.java

@@ -1,22 +1,22 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class ContinueStatement extends Statement {
-    public final String label;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        target.add(Instruction.nop("cont", label).locate(loc()));
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-
-    public ContinueStatement(Location loc, String label) {
-        super(loc);
-        this.label = label;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class ContinueStatement extends Statement {
+    public final String label;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        target.add(Instruction.nop(loc(), "cont", label));
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+    }
+
+    public ContinueStatement(Location loc, String label) {
+        super(loc);
+        this.label = label;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/DebugStatement.java

@@ -1,19 +1,19 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class DebugStatement extends Statement {
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        target.add(Instruction.debug().locate(loc()));
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-
-    public DebugStatement(Location loc) {
-        super(loc);
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class DebugStatement extends Statement {
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        target.add(Instruction.debug(loc()));
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+    }
+
+    public DebugStatement(Location loc) {
+        super(loc);
+    }
+}

src/me/topchetoeu/jscript/compilation/control/DeleteStatement.java

@@ -1,27 +1,27 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class DeleteStatement extends Statement {
-    public final Statement key;
-    public final Statement value;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        value.compile(target, scope, true);
-        key.compile(target, scope, true);
-
-        target.add(Instruction.delete().locate(loc()));
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
-    }
-
-    public DeleteStatement(Location loc, Statement key, Statement value) {
-        super(loc);
-        this.key = key;
-        this.value = value;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class DeleteStatement extends Statement {
+    public final Statement key;
+    public final Statement value;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        value.compile(target, scope, true);
+        key.compile(target, scope, true);
+
+        target.add(Instruction.delete(loc()));
+        if (pollute) target.add(Instruction.loadValue(loc(), true));
+    }
+
+    public DeleteStatement(Location loc, Statement key, Statement value) {
+        super(loc);
+        this.key = key;
+        this.value = value;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/DoWhileStatement.java

@@ -1,79 +1,37 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.CompoundStatement;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.values.ConstantStatement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.engine.values.Values;
-
-public class DoWhileStatement extends Statement {
-    public final Statement condition, body;
-    public final String label;
-
-    @Override
-    public void declare(ScopeRecord globScope) {
-        body.declare(globScope);
-    }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (condition instanceof ConstantStatement) {
-            int start = target.size();
-            body.compile(target, scope, false);
-            int end = target.size();
-            if (Values.toBoolean(((ConstantStatement)condition).value)) {
-                WhileStatement.replaceBreaks(target, label, start, end, end + 1, end + 1);
-            }
-            else {
-                target.add(Instruction.jmp(start - end).locate(loc()));
-                WhileStatement.replaceBreaks(target, label, start, end, start, end + 1);
-            }
-            if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-            return;
-        }
-
-        int start = target.size();
-        body.compileWithDebug(target, scope, false);
-        int mid = target.size();
-        condition.compile(target, scope, true);
-        int end = target.size();
-
-        WhileStatement.replaceBreaks(target, label, start, mid - 1, mid, end + 1);
-        target.add(Instruction.jmpIf(start - end).locate(loc()));
-    }
-
-    @Override
-    public Statement optimize() {
-        var cond = condition.optimize();
-        var b = body.optimize();
-
-        if (b instanceof CompoundStatement) {
-            var comp = (CompoundStatement)b;
-            if (comp.statements.length > 0) {
-                var last = comp.statements[comp.statements.length - 1];
-                if (last instanceof ContinueStatement) comp.statements[comp.statements.length - 1] = new CompoundStatement(loc());
-                if (last instanceof BreakStatement) {
-                    comp.statements[comp.statements.length - 1] = new CompoundStatement(loc());
-                    return new CompoundStatement(loc());
-                }
-            }
-        }
-        else if (b instanceof ContinueStatement) {
-            b = new CompoundStatement(loc());
-        }
-        else if (b instanceof BreakStatement) return new CompoundStatement(loc());
-
-        if (b.pure()) return new DoWhileStatement(loc(), label, cond, new CompoundStatement(loc()));
-        else return new DoWhileStatement(loc(), label, cond, b);
-    }
-
-    public DoWhileStatement(Location loc, String label, Statement condition, Statement body) {
-        super(loc);
-        this.label = label;
-        this.condition = condition;
-        this.body = body;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class DoWhileStatement extends Statement {
+    public final Statement condition, body;
+    public final String label;
+
+    @Override
+    public void declare(ScopeRecord globScope) {
+        body.declare(globScope);
+    }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        int start = target.size();
+        body.compile(target, scope, false, BreakpointType.STEP_OVER);
+        int mid = target.size();
+        condition.compile(target, scope, true, BreakpointType.STEP_OVER);
+        int end = target.size();
+
+        WhileStatement.replaceBreaks(target, label, start, mid - 1, mid, end + 1);
+        target.add(Instruction.jmpIf(loc(), start - end));
+    }
+
+    public DoWhileStatement(Location loc, String label, Statement condition, Statement body) {
+        super(loc);
+        this.label = label;
+        this.condition = condition;
+        this.body = body;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/ForInStatement.java

@@ -1,78 +1,73 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class ForInStatement extends Statement {
-    public final String varName;
-    public final boolean isDeclaration;
-    public final Statement varValue, object, body;
-    public final String label;
-
-    @Override
-    public void declare(ScopeRecord globScope) {
-        body.declare(globScope);
-        if (isDeclaration) globScope.define(varName);
-    }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        var key = scope.getKey(varName);
-        if (key instanceof String) target.add(Instruction.makeVar((String)key));
-
-        if (varValue != null) {
-            varValue.compile(target, scope, true);
-            target.add(Instruction.storeVar(scope.getKey(varName)));
-        }
-
-        object.compile(target, scope, true);
-        target.add(Instruction.keys());
-        
-        int start = target.size();
-        target.add(Instruction.dup());
-        target.add(Instruction.loadMember("length"));
-        target.add(Instruction.loadValue(0));
-        target.add(Instruction.operation(Operation.LESS_EQUALS));
-        int mid = target.size();
-        target.add(Instruction.nop());
-
-        target.add(Instruction.dup());
-        target.add(Instruction.dup());
-        target.add(Instruction.loadMember("length"));
-        target.add(Instruction.loadValue(1));
-        target.add(Instruction.operation(Operation.SUBTRACT));
-        target.add(Instruction.dup(1, 2));
-        target.add(Instruction.loadValue("length"));
-        target.add(Instruction.dup(1, 2));
-        target.add(Instruction.storeMember());
-        target.add(Instruction.loadMember());
-        target.add(Instruction.storeVar(key));
-
-        for (var i = start; i < target.size(); i++) target.get(i).locate(loc());
-
-        body.compileWithDebug(target, scope, false);
-
-        int end = target.size();
-
-        WhileStatement.replaceBreaks(target, label, mid + 1, end, start, end + 1);
-
-        target.add(Instruction.jmp(start - end).locate(loc()));
-        target.add(Instruction.discard().locate(loc()));
-        target.set(mid, Instruction.jmpIf(end - mid + 1).locate(loc()));
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-
-    public ForInStatement(Location loc, String label, boolean isDecl, String varName, Statement varValue, Statement object, Statement body) {
-        super(loc);
-        this.label = label;
-        this.isDeclaration = isDecl;
-        this.varName = varName;
-        this.varValue = varValue;
-        this.object = object;
-        this.body = body;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class ForInStatement extends Statement {
+    public final String varName;
+    public final boolean isDeclaration;
+    public final Statement varValue, object, body;
+    public final String label;
+    public final Location varLocation;
+
+    @Override
+    public void declare(ScopeRecord globScope) {
+        body.declare(globScope);
+        if (isDeclaration) globScope.define(varName);
+    }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        var key = scope.getKey(varName);
+
+        int first = target.size();
+        if (key instanceof String) target.add(Instruction.makeVar(loc(), (String)key));
+
+        if (varValue != null) {
+            varValue.compile(target, scope, true);
+            target.add(Instruction.storeVar(loc(), scope.getKey(varName)));
+        }
+
+        object.compile(target, scope, true, BreakpointType.STEP_OVER);
+        target.add(Instruction.keys(loc(), true));
+
+        int start = target.size();
+        target.add(Instruction.dup(loc()));
+        target.add(Instruction.loadValue(loc(), null));
+        target.add(Instruction.operation(loc(), Operation.EQUALS));
+        int mid = target.size();
+        target.add(Instruction.nop(loc()));
+
+        target.add(Instruction.loadMember(varLocation, "value"));
+        target.add(Instruction.storeVar(object.loc(), key));
+        target.setDebug(BreakpointType.STEP_OVER);
+
+        body.compile(target, scope, false, BreakpointType.STEP_OVER);
+
+        int end = target.size();
+
+        WhileStatement.replaceBreaks(target, label, mid + 1, end, start, end + 1);
+
+        target.add(Instruction.jmp(loc(), start - end));
+        target.add(Instruction.discard(loc()));
+        target.set(mid, Instruction.jmpIf(loc(), end - mid + 1));
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+        target.get(first).locate(loc());
+    }
+
+    public ForInStatement(Location loc, Location varLocation, String label, boolean isDecl, String varName, Statement varValue, Statement object, Statement body) {
+        super(loc);
+        this.varLocation = varLocation;
+        this.label = label;
+        this.isDeclaration = isDecl;
+        this.varName = varName;
+        this.varValue = varValue;
+        this.object = object;
+        this.body = body;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/ForStatement.java

@@ -1,95 +1,47 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.CompoundStatement;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.values.ConstantStatement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.engine.values.Values;
-
-public class ForStatement extends Statement {
-    public final Statement declaration, assignment, condition, body;
-    public final String label;
-
-    @Override
-    public void declare(ScopeRecord globScope) {
-        declaration.declare(globScope);
-        body.declare(globScope);
-    }
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        declaration.compile(target, scope, false);
-
-        if (condition instanceof ConstantStatement) {
-            if (Values.toBoolean(((ConstantStatement)condition).value)) {
-                int start = target.size();
-                body.compile(target, scope, false);
-                int mid = target.size();
-                assignment.compileWithDebug(target, scope, false);
-                int end = target.size();
-                WhileStatement.replaceBreaks(target, label, start, mid, mid, end + 1);
-                target.add(Instruction.jmp(start - target.size()).locate(loc()));
-                if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-            }
-            return;
-        }
-
-        int start = target.size();
-        condition.compile(target, scope, true);
-        int mid = target.size();
-        target.add(Instruction.nop());
-        body.compile(target, scope, false);
-        int beforeAssign = target.size();
-        assignment.compileWithDebug(target, scope, false);
-        int end = target.size();
-
-        WhileStatement.replaceBreaks(target, label, mid + 1, end, beforeAssign, end + 1);
-
-        target.add(Instruction.jmp(start - end).locate(loc()));
-        target.set(mid, Instruction.jmpIfNot(end - mid + 1).locate(loc()));
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-    @Override
-    public Statement optimize() {
-        var decl = declaration.optimize();
-        var asgn = assignment.optimize();
-        var cond = condition.optimize();
-        var b = body.optimize();
-
-        if (asgn.pure()) {
-            if (decl.pure()) return new WhileStatement(loc(), label, cond, b).optimize();
-            else return new CompoundStatement(loc(),
-                decl, new WhileStatement(loc(), label, cond, b)
-            ).optimize();
-        }
-
-        else if (b instanceof ContinueStatement) return new CompoundStatement(loc(),
-            decl, new WhileStatement(loc(), label, cond, new CompoundStatement(loc(), b, asgn))
-        );
-        else if (b instanceof BreakStatement) return decl;
-
-        if (b.pure()) return new ForStatement(loc(), label, decl, cond, asgn, new CompoundStatement(null));
-        else return new ForStatement(loc(), label, decl, cond, asgn, b);
-    }
-
-    public ForStatement(Location loc, String label, Statement declaration, Statement condition, Statement assignment, Statement body) {
-        super(loc);
-        this.label = label;
-        this.declaration = declaration;
-        this.condition = condition;
-        this.assignment = assignment;
-        this.body = body;
-    }
-
-    public static CompoundStatement ofFor(Location loc, String label, Statement declaration, Statement condition, Statement increment, Statement body) {
-        return new CompoundStatement(loc,
-            declaration,
-            new WhileStatement(loc, label, condition, new CompoundStatement(loc,
-                body,
-                increment
-            ))
-        );
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class ForStatement extends Statement {
+    public final Statement declaration, assignment, condition, body;
+    public final String label;
+
+    @Override
+    public void declare(ScopeRecord globScope) {
+        declaration.declare(globScope);
+        body.declare(globScope);
+    }
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        declaration.compile(target, scope, false, BreakpointType.STEP_OVER);
+
+        int start = target.size();
+        condition.compile(target, scope, true, BreakpointType.STEP_OVER);
+        int mid = target.size();
+        target.add(Instruction.nop(null));
+        body.compile(target, scope, false, BreakpointType.STEP_OVER);
+        int beforeAssign = target.size();
+        assignment.compile(target, scope, false, BreakpointType.STEP_OVER);
+        int end = target.size();
+
+        WhileStatement.replaceBreaks(target, label, mid + 1, end, beforeAssign, end + 1);
+
+        target.add(Instruction.jmp(loc(), start - end));
+        target.set(mid, Instruction.jmpIfNot(loc(), end - mid + 1));
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+    }
+
+    public ForStatement(Location loc, String label, Statement declaration, Statement condition, Statement assignment, Statement body) {
+        super(loc);
+        this.label = label;
+        this.declaration = declaration;
+        this.condition = condition;
+        this.assignment = assignment;
+        this.body = body;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/IfStatement.java

@@ -1,77 +1,52 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.CompoundStatement;
-import me.topchetoeu.jscript.compilation.DiscardStatement;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.values.ConstantStatement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.engine.values.Values;
-
-public class IfStatement extends Statement {
-    public final Statement condition, body, elseBody;
-
-    @Override
-    public void declare(ScopeRecord globScope) {
-        body.declare(globScope);
-        if (elseBody != null) elseBody.declare(globScope);
-    }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (condition instanceof ConstantStatement) {
-            if (Values.not(((ConstantStatement)condition).value)) {
-                if (elseBody != null) elseBody.compileWithDebug(target, scope, pollute);
-            }
-            else {
-                body.compileWithDebug(target, scope, pollute);
-            }
-
-            return;
-        }
-
-        condition.compile(target, scope, true);
-
-        if (elseBody == null) {
-            int i = target.size();
-            target.add(Instruction.nop());
-            body.compileWithDebug(target, scope, pollute);
-            int endI = target.size();
-            target.set(i, Instruction.jmpIfNot(endI - i).locate(loc()));
-        }
-        else {
-            int start = target.size();
-            target.add(Instruction.nop());
-            body.compileWithDebug(target, scope, pollute);
-            target.add(Instruction.nop());
-            int mid = target.size();
-            elseBody.compileWithDebug(target, scope, pollute);
-            int end = target.size();
-
-            target.set(start, Instruction.jmpIfNot(mid - start).locate(loc()));
-            target.set(mid - 1, Instruction.jmp(end - mid + 1).locate(loc()));
-        }
-    }
-    
-    @Override
-    public Statement optimize() {
-        var cond = condition.optimize();
-        var b = body.optimize();
-        var e = elseBody == null ? null : elseBody.optimize();
-
-        if (b.pure()) b = new CompoundStatement(null);
-        if (e != null && e.pure()) e = null;
-
-        if (b.pure() && e == null) return new DiscardStatement(loc(), cond).optimize();
-        else return new IfStatement(loc(), cond, b, e);
-    }
-
-    public IfStatement(Location loc, Statement condition, Statement body, Statement elseBody) {
-        super(loc);
-        this.condition = condition;
-        this.body = body;
-        this.elseBody = elseBody;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class IfStatement extends Statement {
+    public final Statement condition, body, elseBody;
+
+    @Override
+    public void declare(ScopeRecord globScope) {
+        body.declare(globScope);
+        if (elseBody != null) elseBody.declare(globScope);
+    }
+
+    @Override public void compile(CompileTarget target, ScopeRecord scope, boolean pollute, BreakpointType breakpoint) {
+        condition.compile(target, scope, true, breakpoint);
+
+        if (elseBody == null) {
+            int i = target.size();
+            target.add(Instruction.nop(null));
+            body.compile(target, scope, pollute, breakpoint);
+            int endI = target.size();
+            target.set(i, Instruction.jmpIfNot(loc(), endI - i));
+        }
+        else {
+            int start = target.size();
+            target.add(Instruction.nop(null));
+            body.compile(target, scope, pollute, breakpoint);
+            target.add(Instruction.nop(null));
+            int mid = target.size();
+            elseBody.compile(target, scope, pollute, breakpoint);
+            int end = target.size();
+
+            target.set(start, Instruction.jmpIfNot(loc(), mid - start));
+            target.set(mid - 1, Instruction.jmp(loc(), end - mid + 1));
+        }
+    }
+    @Override public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        compile(target, scope, pollute, BreakpointType.STEP_IN);
+    }
+
+    public IfStatement(Location loc, Statement condition, Statement body, Statement elseBody) {
+        super(loc);
+        this.condition = condition;
+        this.body = body;
+        this.elseBody = elseBody;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/ReturnStatement.java

@@ -1,23 +1,23 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class ReturnStatement extends Statement {
-    public final Statement value;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (value == null) target.add(Instruction.loadValue(null).locate(loc()));
-        else value.compile(target, scope, true);
-        target.add(Instruction.ret().locate(loc()));
-    }
-
-    public ReturnStatement(Location loc, Statement value) {
-        super(loc);
-        this.value = value;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class ReturnStatement extends Statement {
+    public final Statement value;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        if (value == null) target.add(Instruction.loadValue(loc(), null));
+        else value.compile(target, scope, true);
+        target.add(Instruction.ret(loc()));
+    }
+
+    public ReturnStatement(Location loc, Statement value) {
+        super(loc);
+        this.value = value;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/SwitchStatement.java

@@ -1,85 +1,87 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import java.util.HashMap;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.Instruction.Type;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class SwitchStatement extends Statement {
-    public static class SwitchCase {
-        public final Statement value;
-        public final int statementI;
-
-        public SwitchCase(Statement value, int statementI) {
-            this.value = value;
-            this.statementI = statementI;
-        }
-    }
-
-    public final Statement value;
-    public final SwitchCase[] cases;
-    public final Statement[] body;
-    public final int defaultI;
-
-    @Override
-    public void declare(ScopeRecord varsScope) {
-        for (var stm : body) stm.declare(varsScope);
-    }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        var caseMap = new HashMap<Integer, Integer>();
-        var stmIndexMap = new HashMap<Integer, Integer>();
-
-        value.compile(target, scope, true);
-
-        for (var ccase : cases) {
-            target.add(Instruction.dup().locate(loc()));
-            ccase.value.compile(target, scope, true);
-            target.add(Instruction.operation(Operation.EQUALS).locate(loc()));
-            caseMap.put(target.size(), ccase.statementI);
-            target.add(Instruction.nop());
-        }
-
-        int start = target.size();
-
-        target.add(Instruction.nop());
-
-        for (var stm : body) {
-            stmIndexMap.put(stmIndexMap.size(), target.size());
-            stm.compileWithDebug(target, scope, false);
-        }
-
-        if (defaultI < 0 || defaultI >= body.length) target.set(start, Instruction.jmp(target.size() - start).locate(loc()));
-        else target.set(start, Instruction.jmp(stmIndexMap.get(defaultI) - start)).locate(loc());
-
-        for (int i = start; i < target.size(); i++) {
-            var instr = target.get(i);
-            if (instr.type == Type.NOP && instr.is(0, "break") && instr.get(1) == null) {
-                target.set(i, Instruction.jmp(target.size() - i).locate(instr.location));
-            }
-        }
-        for (var el : caseMap.entrySet()) {
-            var loc = target.get(el.getKey()).location;
-            var i = stmIndexMap.get(el.getValue());
-            if (i == null) i = target.size();
-            target.set(el.getKey(), Instruction.jmpIf(i - el.getKey()).locate(loc));
-            target.setDebug(el.getKey());
-        }
-
-        target.add(Instruction.discard().locate(loc()));
-    }
-
-    public SwitchStatement(Location loc, Statement value, int defaultI, SwitchCase[] cases, Statement[] body) {
-        super(loc);
-        this.value = value;
-        this.defaultI = defaultI;
-        this.cases = cases;
-        this.body = body;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import java.util.HashMap;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.compilation.Instruction.Type;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class SwitchStatement extends Statement {
+    public static class SwitchCase {
+        public final Statement value;
+        public final int statementI;
+
+        public SwitchCase(Statement value, int statementI) {
+            this.value = value;
+            this.statementI = statementI;
+        }
+    }
+
+    public final Statement value;
+    public final SwitchCase[] cases;
+    public final Statement[] body;
+    public final int defaultI;
+
+    @Override
+    public void declare(ScopeRecord varsScope) {
+        for (var stm : body) stm.declare(varsScope);
+    }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        var caseToStatement = new HashMap<Integer, Integer>();
+        var statementToIndex = new HashMap<Integer, Integer>();
+
+        value.compile(target, scope, true, BreakpointType.STEP_OVER);
+
+        for (var ccase : cases) {
+            target.add(Instruction.dup(loc()));
+            ccase.value.compile(target, scope, true);
+            target.add(Instruction.operation(loc(), Operation.EQUALS));
+            caseToStatement.put(target.size(), ccase.statementI);
+            target.add(Instruction.nop(null));
+        }
+
+        int start = target.size();
+
+        target.add(Instruction.nop(null));
+
+        for (var stm : body) {
+            statementToIndex.put(statementToIndex.size(), target.size());
+            stm.compile(target, scope, false, BreakpointType.STEP_OVER);
+        }
+
+        int end = target.size();
+        target.add(Instruction.discard(loc()));
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+
+        if (defaultI < 0 || defaultI >= body.length) target.set(start, Instruction.jmp(loc(), end - start));
+        else target.set(start, Instruction.jmp(loc(), statementToIndex.get(defaultI) - start));
+
+        for (int i = start; i < end; i++) {
+            var instr = target.get(i);
+            if (instr.type == Type.NOP && instr.is(0, "break") && instr.get(1) == null) {
+                target.set(i, Instruction.jmp(loc(), end - i).locate(instr.location));
+            }
+        }
+        for (var el : caseToStatement.entrySet()) {
+            var i = statementToIndex.get(el.getValue());
+            if (i == null) i = end;
+            target.set(el.getKey(), Instruction.jmpIf(loc(), i - el.getKey()));
+        }
+
+    }
+
+    public SwitchStatement(Location loc, Statement value, int defaultI, SwitchCase[] cases, Statement[] body) {
+        super(loc);
+        this.value = value;
+        this.defaultI = defaultI;
+        this.cases = cases;
+        this.body = body;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/ThrowStatement.java

@@ -1,22 +1,22 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class ThrowStatement extends Statement {
-    public final Statement value;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        value.compile(target, scope, true);
-        target.add(Instruction.throwInstr().locate(loc()));
-    }
-
-    public ThrowStatement(Location loc, Statement value) {
-        super(loc);
-        this.value = value;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class ThrowStatement extends Statement {
+    public final Statement value;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        value.compile(target, scope, true);
+        target.add(Instruction.throwInstr(loc()));
+    }
+
+    public ThrowStatement(Location loc, Statement value) {
+        super(loc);
+        this.value = value;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/TryStatement.java

@@ -1,59 +1,61 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.GlobalScope;
-import me.topchetoeu.jscript.engine.scope.LocalScopeRecord;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class TryStatement extends Statement {
-    public final Statement tryBody;
-    public final Statement catchBody;
-    public final Statement finallyBody;
-    public final String name;
-
-    @Override
-    public void declare(ScopeRecord globScope) {
-        tryBody.declare(globScope);
-        if (catchBody != null) catchBody.declare(globScope);
-        if (finallyBody != null) finallyBody.declare(globScope);
-    }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        target.add(Instruction.nop());
-
-        int start = target.size(), tryN, catchN = -1, finN = -1;
-
-        tryBody.compile(target, scope, false);
-        tryN = target.size() - start;
-
-        if (catchBody != null) {
-            int tmp = target.size();
-            var local = scope instanceof GlobalScope ? scope.child() : (LocalScopeRecord)scope;
-            local.define(name, true);
-            catchBody.compile(target, scope, false);
-            local.undefine();
-            catchN = target.size() - tmp;
-        }
-
-        if (finallyBody != null) {
-            int tmp = target.size();
-            finallyBody.compile(target, scope, false);
-            finN = target.size() - tmp;
-        }
-
-        target.set(start - 1, Instruction.tryInstr(tryN, catchN, finN).locate(loc()));
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-
-    public TryStatement(Location loc, Statement tryBody, Statement catchBody, Statement finallyBody, String name) {
-        super(loc);
-        this.tryBody = tryBody;
-        this.catchBody = catchBody;
-        this.finallyBody = finallyBody;
-        this.name = name;
-    }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.engine.scope.GlobalScope;
+import me.topchetoeu.jscript.engine.scope.LocalScopeRecord;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class TryStatement extends Statement {
+    public final Statement tryBody;
+    public final Statement catchBody;
+    public final Statement finallyBody;
+    public final String name;
+
+    @Override
+    public void declare(ScopeRecord globScope) {
+        tryBody.declare(globScope);
+        if (catchBody != null) catchBody.declare(globScope);
+        if (finallyBody != null) finallyBody.declare(globScope);
+    }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute, BreakpointType bpt) {
+        target.add(Instruction.nop(null));
+
+        int start = target.size(), catchStart = -1, finallyStart = -1;
+
+        tryBody.compile(target, scope, false);
+        target.add(Instruction.tryEnd(loc()));
+
+        if (catchBody != null) {
+            catchStart = target.size() - start;
+            var local = scope instanceof GlobalScope ? scope.child() : (LocalScopeRecord)scope;
+            local.define(name, true);
+            catchBody.compile(target, scope, false);
+            local.undefine();
+            target.add(Instruction.tryEnd(loc()));
+        }
+
+        if (finallyBody != null) {
+            finallyStart = target.size() - start;
+            finallyBody.compile(target, scope, false);
+            target.add(Instruction.tryEnd(loc()));
+        }
+
+        target.set(start - 1, Instruction.tryStart(loc(), catchStart, finallyStart, target.size() - start));
+        target.setDebug(start - 1, BreakpointType.STEP_OVER);
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+    }
+
+    public TryStatement(Location loc, Statement tryBody, Statement catchBody, Statement finallyBody, String name) {
+        super(loc);
+        this.tryBody = tryBody;
+        this.catchBody = catchBody;
+        this.finallyBody = finallyBody;
+        this.name = name;
+    }
+}

src/me/topchetoeu/jscript/compilation/control/WhileStatement.java

@@ -1,93 +1,54 @@
-package me.topchetoeu.jscript.compilation.control;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.CompoundStatement;
-import me.topchetoeu.jscript.compilation.DiscardStatement;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Instruction.Type;
-import me.topchetoeu.jscript.compilation.values.ConstantStatement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.engine.values.Values;
-
-public class WhileStatement extends Statement {
-    public final Statement condition, body;
-    public final String label;
-
-    @Override
-    public void declare(ScopeRecord globScope) {
-        body.declare(globScope);
-    }
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (condition instanceof ConstantStatement) {
-            if (Values.toBoolean(((ConstantStatement)condition).value)) {
-                int start = target.size();
-                body.compile(target, scope, false);
-                int end = target.size();
-                replaceBreaks(target, label, start, end, start, end + 1);
-                target.add(Instruction.jmp(start - target.size()).locate(loc()));
-                return;
-            }
-        }
-
-        int start = target.size();
-        condition.compile(target, scope, true);
-        int mid = target.size();
-        target.add(Instruction.nop());
-        body.compile(target, scope, false);
-
-        int end = target.size();
-
-        replaceBreaks(target, label, mid + 1, end, start, end + 1);
-
-        target.add(Instruction.jmp(start - end).locate(loc()));
-        target.set(mid, Instruction.jmpIfNot(end - mid + 1).locate(loc()));
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-    @Override
-    public Statement optimize() {
-        var cond = condition.optimize();
-        var b = body.optimize();
-
-        if (b instanceof ContinueStatement) {
-            b = new CompoundStatement(loc());
-        }
-        else if (b instanceof BreakStatement) return new DiscardStatement(loc(), cond).optimize();
-
-        if (b.pure()) return new WhileStatement(loc(), label, cond, new CompoundStatement(null));
-        else return new WhileStatement(loc(), label, cond, b);
-    }
-
-    public WhileStatement(Location loc, String label, Statement condition, Statement body) {
-        super(loc);
-        this.label = label;
-        this.condition = condition;
-        this.body = body;
-    }
-
-    public static void replaceBreaks(CompileTarget target, String label, int start, int end, int continuePoint, int breakPoint) {
-        for (int i = start; i < end; i++) {
-            var instr = target.get(i);
-            if (instr.type == Type.NOP && instr.is(0, "cont") && (instr.get(1) == null || instr.is(1, label))) {
-                target.set(i, Instruction.jmp(continuePoint - i));
-                target.get(i).location = instr.location;
-            }
-            if (instr.type == Type.NOP && instr.is(0, "break") && (instr.get(1) == null || instr.is(1, label))) {
-                target.set(i, Instruction.jmp(breakPoint - i));
-                target.get(i).location = instr.location;
-            }
-        }
-    }
-
-    // public static CompoundStatement ofFor(Location loc, String label, Statement declaration, Statement condition, Statement increment, Statement body) {
-    //     return new CompoundStatement(loc,
-    //         declaration,
-    //         new WhileStatement(loc, label, condition, new CompoundStatement(loc,
-    //             body,
-    //             increment
-    //         ))
-    //     );
-    // }
-}
+package me.topchetoeu.jscript.compilation.control;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.compilation.Instruction.Type;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class WhileStatement extends Statement {
+    public final Statement condition, body;
+    public final String label;
+
+    @Override
+    public void declare(ScopeRecord globScope) {
+        body.declare(globScope);
+    }
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        int start = target.size();
+        condition.compile(target, scope, true);
+        int mid = target.size();
+        target.add(Instruction.nop(null));
+        body.compile(target, scope, false, BreakpointType.STEP_OVER);
+
+        int end = target.size();
+
+        replaceBreaks(target, label, mid + 1, end, start, end + 1);
+
+        target.add(Instruction.jmp(loc(), start - end));
+        target.set(mid, Instruction.jmpIfNot(loc(), end - mid + 1));
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+    }
+
+    public WhileStatement(Location loc, String label, Statement condition, Statement body) {
+        super(loc);
+        this.label = label;
+        this.condition = condition;
+        this.body = body;
+    }
+
+    public static void replaceBreaks(CompileTarget target, String label, int start, int end, int continuePoint, int breakPoint) {
+        for (int i = start; i < end; i++) {
+            var instr = target.get(i);
+            if (instr.type == Type.NOP && instr.is(0, "cont") && (instr.get(1) == null || instr.is(1, label))) {
+                target.set(i, Instruction.jmp(instr.location, continuePoint - i).setDbgData(target.get(i)));
+            }
+            if (instr.type == Type.NOP && instr.is(0, "break") && (instr.get(1) == null || instr.is(1, label))) {
+                target.set(i, Instruction.jmp(instr.location, breakPoint - i).setDbgData(target.get(i)));
+            }
+        }
+    }
+}

src/me/topchetoeu/jscript/compilation/values/ArrayStatement.java

@@ -1,4 +1,4 @@
-package me.topchetoeu.jscript.compilation.control;
+package me.topchetoeu.jscript.compilation.values;
 
 import me.topchetoeu.jscript.Location;
 import me.topchetoeu.jscript.compilation.CompileTarget;
@@ -9,23 +9,29 @@ import me.topchetoeu.jscript.engine.scope.ScopeRecord;
 public class ArrayStatement extends Statement {
     public final Statement[] statements;
 
-    @Override
-    public boolean pure() { return true; }
+    @Override public boolean pure() {
+        for (var stm : statements) {
+            if (!stm.pure()) return false;
+        }
+
+        return true;
+    }
 
     @Override
     public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        target.add(Instruction.loadArr(statements.length).locate(loc()));
-        var i = 0;
-        for (var el : statements) {
+        target.add(Instruction.loadArr(loc(), statements.length));
+
+        for (var i = 0; i < statements.length; i++) {
+            var el = statements[i];
             if (el != null) {
-                target.add(Instruction.dup().locate(loc()));
-                target.add(Instruction.loadValue(i).locate(loc()));
+                target.add(Instruction.dup(loc()));
+                target.add(Instruction.loadValue(loc(), i));
                 el.compile(target, scope, true);
-                target.add(Instruction.storeMember().locate(loc()));
+                target.add(Instruction.storeMember(loc()));
             }
-            i++;
         }
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
+
+        if (!pollute) target.add(Instruction.discard(loc()));
     }
 
     public ArrayStatement(Location loc, Statement[] statements) {

src/me/topchetoeu/jscript/compilation/values/CallStatement.java

@@ -1,40 +1,51 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class CallStatement extends Statement {
-    public final Statement func;
-    public final Statement[] args;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (func instanceof IndexStatement) {
-            ((IndexStatement)func).compile(target, scope, true, true);
-        }
-        else {
-            target.add(Instruction.loadValue(null).locate(loc()));
-            func.compile(target, scope, true);
-        }
-
-        for (var arg : args) arg.compile(target, scope, true);
-
-        target.add(Instruction.call(args.length).locate(loc()));
-        target.setDebug();
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
-    }
-
-    public CallStatement(Location loc, Statement func, Statement ...args) {
-        super(loc);
-        this.func = func;
-        this.args = args;
-    }
-    public CallStatement(Location loc, Statement obj, Object key, Statement ...args) {
-        super(loc);
-        this.func = new IndexStatement(loc, obj, new ConstantStatement(loc, key));
-        this.args = args;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class CallStatement extends Statement {
+    public final Statement func;
+    public final Statement[] args;
+    public final boolean isNew;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute, BreakpointType type) {
+        if (isNew) func.compile(target, scope, true);
+        else if (func instanceof IndexStatement) {
+            ((IndexStatement)func).compile(target, scope, true, true);
+        }
+        else {
+            target.add(Instruction.loadValue(loc(), null));
+            func.compile(target, scope, true);
+        }
+
+        for (var arg : args) arg.compile(target, scope, true);
+
+        if (isNew) target.add(Instruction.callNew(loc(), args.length));
+        else target.add(Instruction.call(loc(), args.length));
+        target.setDebug(type);
+
+        if (!pollute) target.add(Instruction.discard(loc()));
+    }
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        compile(target, scope, pollute, BreakpointType.STEP_IN);
+    }
+
+    public CallStatement(Location loc, boolean isNew, Statement func, Statement ...args) {
+        super(loc);
+        this.isNew = isNew;
+        this.func = func;
+        this.args = args;
+    }
+    public CallStatement(Location loc, boolean isNew, Statement obj, Object key, Statement ...args) {
+        super(loc);
+        this.isNew = isNew;
+        this.func = new IndexStatement(loc, obj, new ConstantStatement(loc, key));
+        this.args = args;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/ChangeStatement.java

@@ -1,28 +1,32 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.AssignableStatement;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class ChangeStatement extends Statement {
-    public final AssignableStatement value;
-    public final double addAmount;
-    public final boolean postfix;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        value.toAssign(new ConstantStatement(loc(), -addAmount), Operation.SUBTRACT).compile(target, scope, postfix);
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
-    }
-
-    public ChangeStatement(Location loc, AssignableStatement value, double addAmount, boolean postfix) {
-        super(loc);
-        this.value = value;
-        this.addAmount = addAmount;
-        this.postfix = postfix;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.AssignableStatement;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class ChangeStatement extends Statement {
+    public final AssignableStatement value;
+    public final double addAmount;
+    public final boolean postfix;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        value.toAssign(new ConstantStatement(loc(), -addAmount), Operation.SUBTRACT).compile(target, scope, true);
+        if (!pollute) target.add(Instruction.discard(loc()));
+        else if (postfix) {
+            target.add(Instruction.loadValue(loc(), addAmount));
+            target.add(Instruction.operation(loc(), Operation.SUBTRACT));
+        }
+    }
+
+    public ChangeStatement(Location loc, AssignableStatement value, double addAmount, boolean postfix) {
+        super(loc);
+        this.value = value;
+        this.addAmount = addAmount;
+        this.postfix = postfix;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/ConstantStatement.java

@@ -1,24 +1,23 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class ConstantStatement extends Statement {
-    public final Object value;
-
-    @Override
-    public boolean pure() { return true; }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (pollute) target.add(Instruction.loadValue(value).locate(loc()));
-    }
-
-    public ConstantStatement(Location loc, Object val) {
-        super(loc);
-        this.value = val;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class ConstantStatement extends Statement {
+    public final Object value;
+
+    @Override public boolean pure() { return true; }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        if (pollute) target.add(Instruction.loadValue(loc(), value));
+    }
+
+    public ConstantStatement(Location loc, Object val) {
+        super(loc);
+        this.value = val;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/DiscardStatement.java

@@ -1,27 +1,24 @@
-package me.topchetoeu.jscript.compilation;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.values.ConstantStatement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class DiscardStatement extends Statement {
-    public final Statement value;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        value.compile(target, scope, false);
-        
-    }
-    @Override
-    public Statement optimize() {
-        if (value == null) return this;
-        var val = value.optimize();
-        if (val.pure()) return new ConstantStatement(loc(), null);
-        else return new DiscardStatement(loc(), val);
-    }
-
-    public DiscardStatement(Location loc, Statement val) {
-        super(loc);
-        this.value = val;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class DiscardStatement extends Statement {
+    public final Statement value;
+
+    @Override public boolean pure() { return value.pure(); }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        value.compile(target, scope, false);
+        if (pollute) target.add(Instruction.loadValue(loc(), null));
+    }
+
+    public DiscardStatement(Location loc, Statement val) {
+        super(loc);
+        this.value = val;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/FunctionStatement.java

@@ -1,112 +1,139 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import java.util.Random;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.CompoundStatement;
-import me.topchetoeu.jscript.compilation.FunctionBody;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.Instruction.Type;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.exceptions.SyntaxException;
-
-public class FunctionStatement extends Statement {
-    public final CompoundStatement body;
-    public final String name;
-    public final String[] args;
-
-    private static Random rand = new Random();
-
-    @Override
-    public boolean pure() { return name == null; }
-
-    @Override
-    public void declare(ScopeRecord scope) {
-        if (name != null) scope.define(name);
-    }
-
-    public static void checkBreakAndCont(CompileTarget target, int start) {
-        for (int i = start; i < target.size(); i++) {
-            if (target.get(i).type == Type.NOP) {
-                if (target.get(i).is(0, "break") ) {
-                    throw new SyntaxException(target.get(i).location, "Break was placed outside a loop.");
-                }
-                if (target.get(i).is(0, "cont")) {
-                    throw new SyntaxException(target.get(i).location, "Continue was placed outside a loop.");
-                }
-            }
-        }
-    }
-
-    public void compile(CompileTarget target, ScopeRecord scope, String name, boolean isStatement) {
-        for (var i = 0; i < args.length; i++) {
-            for (var j = 0; j < i; j++) {
-                if (args[i].equals(args[j])){
-                    target.add(Instruction.throwSyntax(new SyntaxException(loc(), "Duplicate parameter '" + args[i] + "'.")));
-                    return;
-                }
-            }
-        }
-        var subscope = scope.child();
-
-        int start = target.size();
-        var funcTarget = new CompileTarget(target.functions, target.breakpoints);
-
-        subscope.define("this");
-        var argsVar = subscope.define("arguments");
-
-        if (args.length > 0) {
-            for (var i = 0; i < args.length; i++) {
-                funcTarget.add(Instruction.loadVar(argsVar).locate(loc()));
-                funcTarget.add(Instruction.loadMember(i).locate(loc()));
-                funcTarget.add(Instruction.storeVar(subscope.define(args[i])).locate(loc()));
-            }
-        }
-
-        if (!isStatement && this.name != null) {
-            funcTarget.add(Instruction.storeSelfFunc((int)subscope.define(this.name)));
-        }
-
-        body.declare(subscope);
-        body.compile(funcTarget, subscope, false);
-        funcTarget.add(Instruction.ret().locate(loc()));
-        checkBreakAndCont(funcTarget, start);
-
-        var id = rand.nextLong();
-
-        target.add(Instruction.loadFunc(id, subscope.localsCount(), args.length, subscope.getCaptures()).locate(loc()));
-        target.functions.put(id, new FunctionBody(funcTarget.array(), subscope.captures(), subscope.locals()));
-
-        if (name == null) name = this.name;
-
-        if (name != null) {
-            target.add(Instruction.dup().locate(loc()));
-            target.add(Instruction.loadValue("name").locate(loc()));
-            target.add(Instruction.loadValue(name).locate(loc()));
-            target.add(Instruction.storeMember().locate(loc()));
-        }
-
-        if (this.name != null && isStatement) {
-            var key = scope.getKey(this.name);
-
-            if (key instanceof String) target.add(Instruction.makeVar((String)key).locate(loc()));
-            target.add(Instruction.storeVar(scope.getKey(this.name), false).locate(loc()));
-        }
-
-    }
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        compile(target, scope, null, false);
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
-    }
-
-    public FunctionStatement(Location loc, String name, String[] args, CompoundStatement body) {
-        super(loc);
-        this.name = name;
-
-        this.args = args;
-        this.body = body;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import java.util.Random;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.CompoundStatement;
+import me.topchetoeu.jscript.compilation.FunctionBody;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.compilation.Instruction.Type;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+import me.topchetoeu.jscript.exceptions.SyntaxException;
+
+public class FunctionStatement extends Statement {
+    public final CompoundStatement body;
+    public final String varName;
+    public final String[] args;
+    public final boolean statement;
+    public final Location end;
+
+    private static Random rand = new Random();
+
+    @Override public boolean pure() { return varName == null && statement; }
+
+    @Override
+    public void declare(ScopeRecord scope) {
+        if (varName != null && statement) scope.define(varName);
+    }
+
+    public static void checkBreakAndCont(CompileTarget target, int start) {
+        for (int i = start; i < target.size(); i++) {
+            if (target.get(i).type == Type.NOP) {
+                if (target.get(i).is(0, "break") ) {
+                    throw new SyntaxException(target.get(i).location, "Break was placed outside a loop.");
+                }
+                if (target.get(i).is(0, "cont")) {
+                    throw new SyntaxException(target.get(i).location, "Continue was placed outside a loop.");
+                }
+            }
+        }
+    }
+
+    private long compileBody(CompileTarget target, ScopeRecord scope, boolean polute, BreakpointType bp) {
+        for (var i = 0; i < args.length; i++) {
+            for (var j = 0; j < i; j++) {
+                if (args[i].equals(args[j])) {
+                    throw new SyntaxException(loc(), "Duplicate parameter '" + args[i] + "'.");
+                }
+            }
+        }
+
+        var id = rand.nextLong();
+        var subscope = scope.child();
+        var subtarget = new CompileTarget(target.functions, target.breakpoints);
+
+        subscope.define("this");
+        var argsVar = subscope.define("arguments");
+
+        if (args.length > 0) {
+            for (var i = 0; i < args.length; i++) {
+                subtarget.add(Instruction.loadVar(loc(), argsVar));
+                subtarget.add(Instruction.loadMember(loc(), i));
+                subtarget.add(Instruction.storeVar(loc(), subscope.define(args[i])));
+            }
+        }
+
+        if (!statement && this.varName != null) {
+            subtarget.add(Instruction.storeSelfFunc(loc(), (int)subscope.define(this.varName)));
+            subtarget.setDebug(bp);
+        }
+
+        body.declare(subscope);
+        body.compile(subtarget, subscope, false);
+        subtarget.add(Instruction.ret(end));
+        checkBreakAndCont(subtarget, 0);
+
+        if (polute) target.add(Instruction.loadFunc(loc(), id, subscope.getCaptures()));
+        target.functions.put(id, new FunctionBody(
+            subscope.localsCount(), args.length,
+            subtarget.array(), subscope.captures(), subscope.locals()
+        ));
+
+        return id;
+    }
+
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute, String name, BreakpointType bp) {
+        if (this.varName != null) name = this.varName;
+
+        var hasVar = this.varName != null && statement;
+        var hasName = name != null;
+
+        compileBody(target, scope, pollute || hasVar || hasName, bp);
+
+        if (hasName) {
+            if (pollute || hasVar) target.add(Instruction.dup(loc()));
+            target.add(Instruction.loadValue(loc(), "name"));
+            target.add(Instruction.loadValue(loc(), name));
+            target.add(Instruction.storeMember(loc()));
+        }
+
+        if (hasVar) {
+            var key = scope.getKey(this.varName);
+
+            if (key instanceof String) target.add(Instruction.makeVar(loc(), (String)key));
+            target.add(Instruction.storeVar(loc(), scope.getKey(this.varName), false));
+        }
+    }
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute, String name) {
+        compile(target, scope, pollute, name, BreakpointType.NONE);
+    }
+    @Override public void compile(CompileTarget target, ScopeRecord scope, boolean pollute, BreakpointType bp) {
+        compile(target, scope, pollute, (String)null, bp);
+    }
+    @Override public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        compile(target, scope, pollute, (String)null, BreakpointType.NONE);
+    }
+
+    public FunctionStatement(Location loc, Location end, String varName, String[] args, boolean statement, CompoundStatement body) {
+        super(loc);
+
+        this.end = end;
+        this.varName = varName;
+        this.statement = statement;
+
+        this.args = args;
+        this.body = body;
+    }
+
+    public static void compileWithName(Statement stm, CompileTarget target, ScopeRecord scope, boolean pollute, String name) {
+        if (stm instanceof FunctionStatement) ((FunctionStatement)stm).compile(target, scope, pollute, name);
+        else stm.compile(target, scope, pollute);
+    }
+    public static void compileWithName(Statement stm, CompileTarget target, ScopeRecord scope, boolean pollute, String name, BreakpointType bp) {
+        if (stm instanceof FunctionStatement) ((FunctionStatement)stm).compile(target, scope, pollute, name, bp);
+        else stm.compile(target, scope, pollute, bp);
+    }
+}

src/me/topchetoeu/jscript/compilation/values/GlobalThisStatement.java

@@ -1,21 +1,20 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class GlobalThisStatement extends Statement {
-    @Override
-    public boolean pure() { return true; }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (pollute) target.add(Instruction.loadGlob().locate(loc()));
-    }
-
-    public GlobalThisStatement(Location loc) {
-        super(loc);
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class GlobalThisStatement extends Statement {
+    @Override public boolean pure() { return true; }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        if (pollute) target.add(Instruction.loadGlob(loc()));
+    }
+
+    public GlobalThisStatement(Location loc) {
+        super(loc);
+    }
+}

src/me/topchetoeu/jscript/compilation/values/IndexAssignStatement.java

@@ -1,47 +1,48 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class IndexAssignStatement extends Statement {
-    public final Statement object;
-    public final Statement index;
-    public final Statement value;
-    public final Operation operation;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (operation != null) {
-            object.compile(target, scope, true);
-            index.compile(target, scope, true);
-            target.add(Instruction.dup(2, 0).locate(loc()));
-
-            target.add(Instruction.loadMember().locate(loc()));
-            value.compile(target, scope, true);
-            target.add(Instruction.operation(operation).locate(loc()));
-
-            target.add(Instruction.storeMember(pollute).locate(loc()));
-            target.setDebug();
-        }
-        else {
-            object.compile(target, scope, true);
-            index.compile(target, scope, true);
-            value.compile(target, scope, true);
-
-            target.add(Instruction.storeMember(pollute).locate(loc()));
-            target.setDebug();
-        }
-    }
-
-    public IndexAssignStatement(Location loc, Statement object, Statement index, Statement value, Operation operation) {
-        super(loc);
-        this.object = object;
-        this.index = index;
-        this.value = value;
-        this.operation = operation;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class IndexAssignStatement extends Statement {
+    public final Statement object;
+    public final Statement index;
+    public final Statement value;
+    public final Operation operation;
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        if (operation != null) {
+            object.compile(target, scope, true);
+            index.compile(target, scope, true);
+            target.add(Instruction.dup(loc(), 2));
+
+            target.add(Instruction.loadMember(loc()));
+            value.compile(target, scope, true);
+            target.add(Instruction.operation(loc(), operation));
+
+            target.add(Instruction.storeMember(loc(), pollute));
+            target.setDebug(BreakpointType.STEP_IN);
+        }
+        else {
+            object.compile(target, scope, true);
+            index.compile(target, scope, true);
+            value.compile(target, scope, true);
+
+            target.add(Instruction.storeMember(loc(), pollute));
+            target.setDebug(BreakpointType.STEP_IN);
+        }
+    }
+
+    public IndexAssignStatement(Location loc, Statement object, Statement index, Statement value, Operation operation) {
+        super(loc);
+        this.object = object;
+        this.index = index;
+        this.value = value;
+        this.operation = operation;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/IndexStatement.java

@@ -1,51 +1,49 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.AssignableStatement;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class IndexStatement extends AssignableStatement {
-    public final Statement object;
-    public final Statement index;
-
-    @Override
-    public boolean pure() { return true; }
-
-    @Override
-    public Statement toAssign(Statement val, Operation operation) {
-        return new IndexAssignStatement(loc(), object, index, val, operation);
-    }
-    public void compile(CompileTarget target, ScopeRecord scope, boolean dupObj, boolean pollute) {
-        object.compile(target, scope, true);
-        if (dupObj) target.add(Instruction.dup().locate(loc()));
-        if (index instanceof ConstantStatement) {
-            target.add(Instruction.loadMember(((ConstantStatement)index).value).locate(loc()));
-            target.setDebug();
-            return;
-        }
-
-        index.compile(target, scope, true);
-        target.add(Instruction.loadMember().locate(loc()));
-        target.setDebug();
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
-    }
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        compile(target, scope, false, pollute);
-    }
-
-    public IndexStatement(Location loc, Statement object, Statement index) {
-        super(loc);
-        this.object = object;
-        this.index = index;
-    }
-    public IndexStatement(Location loc, Statement object, Object index) {
-        super(loc);
-        this.object = object;
-        this.index = new ConstantStatement(loc, index);
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.AssignableStatement;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.Instruction.BreakpointType;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class IndexStatement extends AssignableStatement {
+    public final Statement object;
+    public final Statement index;
+
+    @Override
+    public Statement toAssign(Statement val, Operation operation) {
+        return new IndexAssignStatement(loc(), object, index, val, operation);
+    }
+    public void compile(CompileTarget target, ScopeRecord scope, boolean dupObj, boolean pollute) {
+        object.compile(target, scope, true);
+        if (dupObj) target.add(Instruction.dup(loc()));
+        if (index instanceof ConstantStatement) {
+            target.add(Instruction.loadMember(loc(), ((ConstantStatement)index).value));
+            target.setDebug(BreakpointType.STEP_IN);
+            return;
+        }
+
+        index.compile(target, scope, true);
+        target.add(Instruction.loadMember(loc()));
+        target.setDebug(BreakpointType.STEP_IN);
+        if (!pollute) target.add(Instruction.discard(loc()));
+    }
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        compile(target, scope, false, pollute);
+    }
+
+    public IndexStatement(Location loc, Statement object, Statement index) {
+        super(loc);
+        this.object = object;
+        this.index = index;
+    }
+    public IndexStatement(Location loc, Statement object, Object index) {
+        super(loc);
+        this.object = object;
+        this.index = new ConstantStatement(loc, index);
+    }
+}

src/me/topchetoeu/jscript/compilation/values/LazyAndStatement.java

@@ -1,42 +1,39 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.engine.values.Values;
-
-public class LazyAndStatement extends Statement {
-    public final Statement first, second;
-
-    @Override
-    public boolean pure() {
-        return first.pure() && second.pure();
-    }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (first instanceof ConstantStatement) {
-            if (Values.not(((ConstantStatement)first).value)) {
-                first.compile(target, scope, pollute);
-            }
-            else second.compile(target, scope, pollute);
-            return;
-        }
-
-        first.compile(target, scope, true);
-        if (pollute) target.add(Instruction.dup().locate(loc()));
-        int start = target.size();
-        target.add(Instruction.nop());
-        target.add(Instruction.discard().locate(loc()));
-        second.compile(target, scope, pollute);
-        target.set(start, Instruction.jmpIfNot(target.size() - start).locate(loc()));
-    }
-
-    public LazyAndStatement(Location loc, Statement first, Statement second) {
-        super(loc);
-        this.first = first;
-        this.second = second;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+import me.topchetoeu.jscript.engine.values.Values;
+
+public class LazyAndStatement extends Statement {
+    public final Statement first, second;
+
+    @Override public boolean pure() { return first.pure() && second.pure(); }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        if (first instanceof ConstantStatement) {
+            if (Values.not(((ConstantStatement)first).value)) {
+                first.compile(target, scope, pollute);
+            }
+            else second.compile(target, scope, pollute);
+            return;
+        }
+
+        first.compile(target, scope, true);
+        if (pollute) target.add(Instruction.dup(loc()));
+        int start = target.size();
+        target.add(Instruction.nop(null));
+        if (pollute) target.add(Instruction.discard(loc()));
+        second.compile(target, scope, pollute);
+        target.set(start, Instruction.jmpIfNot(loc(), target.size() - start));
+    }
+
+    public LazyAndStatement(Location loc, Statement first, Statement second) {
+        super(loc);
+        this.first = first;
+        this.second = second;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/LazyOrStatement.java

@@ -1,42 +1,39 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.engine.values.Values;
-
-public class LazyOrStatement extends Statement {
-    public final Statement first, second;
-
-    @Override
-    public boolean pure() {
-        return first.pure() && second.pure();
-    }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (first instanceof ConstantStatement) {
-            if (Values.not(((ConstantStatement)first).value)) {
-                second.compile(target, scope, pollute);
-            }
-            else first.compile(target, scope, pollute);
-            return;
-        }
-
-        first.compile(target, scope, true);
-        if (pollute) target.add(Instruction.dup().locate(loc()));
-        int start = target.size();
-        target.add(Instruction.nop());
-        target.add(Instruction.discard().locate(loc()));
-        second.compile(target, scope, pollute);
-        target.set(start, Instruction.jmpIf(target.size() - start).locate(loc()));
-    }
-
-    public LazyOrStatement(Location loc, Statement first, Statement second) {
-        super(loc);
-        this.first = first;
-        this.second = second;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+import me.topchetoeu.jscript.engine.values.Values;
+
+public class LazyOrStatement extends Statement {
+    public final Statement first, second;
+
+    @Override public boolean pure() { return first.pure() && second.pure(); }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        if (first instanceof ConstantStatement) {
+            if (Values.not(((ConstantStatement)first).value)) {
+                second.compile(target, scope, pollute);
+            }
+            else first.compile(target, scope, pollute);
+            return;
+        }
+
+        first.compile(target, scope, true);
+        if (pollute) target.add(Instruction.dup(loc()));
+        int start = target.size();
+        target.add(Instruction.nop(null));
+        if (pollute) target.add(Instruction.discard(loc()));
+        second.compile(target, scope, pollute);
+        target.set(start, Instruction.jmpIf(loc(), target.size() - start));
+    }
+
+    public LazyOrStatement(Location loc, Statement first, Statement second) {
+        super(loc);
+        this.first = first;
+        this.second = second;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/NewStatement.java

@@ -1,28 +0,0 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class NewStatement extends Statement {
-    public final Statement func;
-    public final Statement[] args;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        func.compile(target, scope, true);
-
-        for (var arg : args) arg.compile(target, scope, true);
-
-        target.add(Instruction.callNew(args.length).locate(loc()));
-        target.setDebug();
-    }
-
-    public NewStatement(Location loc, Statement func, Statement ...args) {
-        super(loc);
-        this.func = func;
-        this.args = args;
-    }
-}

src/me/topchetoeu/jscript/compilation/values/ObjectStatement.java

@@ -1,56 +1,63 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import java.util.ArrayList;
-import java.util.Map;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class ObjectStatement extends Statement {
-    public final Map<Object, Statement> map;
-    public final Map<Object, FunctionStatement> getters;
-    public final Map<Object, FunctionStatement> setters;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        target.add(Instruction.loadObj().locate(loc()));
-
-        for (var el : map.entrySet()) {
-            target.add(Instruction.dup().locate(loc()));
-            target.add(Instruction.loadValue(el.getKey()).locate(loc()));
-            var val = el.getValue();
-            if (val instanceof FunctionStatement) ((FunctionStatement)val).compile(target, scope, el.getKey().toString(), false);
-            else val.compile(target, scope, true);
-            target.add(Instruction.storeMember().locate(loc()));
-        }
-
-        var keys = new ArrayList<Object>();
-        keys.addAll(getters.keySet());
-        keys.addAll(setters.keySet());
-
-        for (var key : keys) {
-            if (key instanceof String) target.add(Instruction.loadValue((String)key).locate(loc()));
-            else target.add(Instruction.loadValue((Double)key).locate(loc()));
-
-            if (getters.containsKey(key)) getters.get(key).compile(target, scope, true);
-            else target.add(Instruction.loadValue(null).locate(loc()));
-
-            if (setters.containsKey(key)) setters.get(key).compile(target, scope, true);
-            else target.add(Instruction.loadValue(null).locate(loc()));
-
-            target.add(Instruction.defProp().locate(loc()));
-        }
-
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
-    }
-
-    public ObjectStatement(Location loc, Map<Object, Statement> map, Map<Object, FunctionStatement> getters, Map<Object, FunctionStatement> setters) {
-        super(loc);
-        this.map = map;
-        this.getters = getters;
-        this.setters = setters;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import java.util.ArrayList;
+import java.util.Map;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class ObjectStatement extends Statement {
+    public final Map<Object, Statement> map;
+    public final Map<Object, FunctionStatement> getters;
+    public final Map<Object, FunctionStatement> setters;
+
+    @Override public boolean pure() {
+        for (var el : map.values()) {
+            if (!el.pure()) return false;
+        }
+
+        return true;
+    }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        target.add(Instruction.loadObj(loc()));
+
+        for (var el : map.entrySet()) {
+            target.add(Instruction.dup(loc()));
+            target.add(Instruction.loadValue(loc(), el.getKey()));
+            var val = el.getValue();
+            FunctionStatement.compileWithName(val, target, scope, true, el.getKey().toString());
+            target.add(Instruction.storeMember(loc()));
+        }
+
+        var keys = new ArrayList<Object>();
+        keys.addAll(getters.keySet());
+        keys.addAll(setters.keySet());
+
+        for (var key : keys) {
+            if (key instanceof String) target.add(Instruction.loadValue(loc(), (String)key));
+            else target.add(Instruction.loadValue(loc(), (Double)key));
+
+            if (getters.containsKey(key)) getters.get(key).compile(target, scope, true);
+            else target.add(Instruction.loadValue(loc(), null));
+
+            if (setters.containsKey(key)) setters.get(key).compile(target, scope, true);
+            else target.add(Instruction.loadValue(loc(), null));
+
+            target.add(Instruction.defProp(loc()));
+        }
+
+        if (!pollute) target.add(Instruction.discard(loc()));
+    }
+
+    public ObjectStatement(Location loc, Map<Object, Statement> map, Map<Object, FunctionStatement> getters, Map<Object, FunctionStatement> setters) {
+        super(loc);
+        this.map = map;
+        this.getters = getters;
+        this.setters = setters;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/OperationStatement.java

@@ -1,65 +1,37 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.control.ThrowStatement;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.exceptions.EngineException;
-
-public class OperationStatement extends Statement {
-    public final Statement[] args;
-    public final Operation operation;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        for (var arg : args) {
-            arg.compile(target, scope, true);
-        }
-
-        if (pollute) target.add(Instruction.operation(operation).locate(loc()));
-        else target.add(Instruction.discard().locate(loc()));
-    }
-
-    @Override
-    public boolean pure() {
-        for (var arg : args) {
-            if (!arg.pure()) return false;
-        }
-        return true;
-    }
-
-    @Override
-    public Statement optimize() {
-        var args = new Statement[this.args.length];
-        var allConst = true;
-
-        for (var i = 0; i < this.args.length; i++) {
-            args[i] = this.args[i].optimize();
-            if (!(args[i] instanceof ConstantStatement)) allConst = false;
-        }
-
-        if (allConst) {
-            var vals = new Object[this.args.length];
-
-            for (var i = 0; i < args.length; i++) {
-                vals[i] = ((ConstantStatement)args[i]).value;
-            }
-
-            try { return new ConstantStatement(loc(), Values.operation(null, operation, vals)); }
-            catch (EngineException e) { return new ThrowStatement(loc(), new ConstantStatement(loc(), e.value)); }
-        }
-
-        return new OperationStatement(loc(), operation, args);
-
-    }
-
-    public OperationStatement(Location loc, Operation operation, Statement ...args) {
-        super(loc);
-        this.operation = operation;
-        this.args = args;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class OperationStatement extends Statement {
+    public final Statement[] args;
+    public final Operation operation;
+
+    @Override public boolean pure() {
+        for (var el : args) {
+            if (!el.pure()) return false;
+        }
+
+        return true;
+    }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        for (var arg : args) {
+            arg.compile(target, scope, true);
+        }
+
+        if (pollute) target.add(Instruction.operation(loc(), operation));
+        else target.add(Instruction.discard(loc()));
+    }
+
+    public OperationStatement(Location loc, Operation operation, Statement ...args) {
+        super(loc);
+        this.operation = operation;
+        this.args = args;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/RegexStatement.java

@@ -1,26 +1,26 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class RegexStatement extends Statement {
-    public final String pattern, flags;
-
-    @Override
-    public boolean pure() { return true; }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        target.add(Instruction.loadRegex(pattern, flags).locate(loc()));
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
-    }
-
-    public RegexStatement(Location loc, String pattern, String flags) {
-        super(loc);
-        this.pattern = pattern;
-        this.flags = flags;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class RegexStatement extends Statement {
+    public final String pattern, flags;
+
+    // Not really pure, since a function is called, but can be ignored.
+    @Override public boolean pure() { return true; }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        target.add(Instruction.loadRegex(loc(), pattern, flags));
+        if (!pollute) target.add(Instruction.discard(loc()));
+    }
+
+    public RegexStatement(Location loc, String pattern, String flags) {
+        super(loc);
+        this.pattern = pattern;
+        this.flags = flags;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/TypeofStatement.java

@@ -1,51 +1,33 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.control.ArrayStatement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.engine.values.Values;
-
-public class TypeofStatement extends Statement {
-    public final Statement value;
-
-    @Override
-    public boolean pure() { return true; }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (value instanceof VariableStatement) {
-            var i = scope.getKey(((VariableStatement)value).name);
-            if (i instanceof String) {
-                target.add(Instruction.typeof((String)i).locate(loc()));
-                return;
-            }
-        }
-        value.compile(target, scope, pollute);
-        target.add(Instruction.typeof().locate(loc()));
-    }
-
-    @Override
-    public Statement optimize() {
-        var val = value.optimize();
-
-        if (val instanceof ConstantStatement) {
-            return new ConstantStatement(loc(), Values.type(((ConstantStatement)val).value));
-        }
-        else if (
-            val instanceof ObjectStatement ||
-            val instanceof ArrayStatement ||
-            val instanceof GlobalThisStatement
-        ) return new ConstantStatement(loc(), "object");
-        else if(val instanceof FunctionStatement) return new ConstantStatement(loc(), "function");
-
-        return new TypeofStatement(loc(), val);
-    }
-
-    public TypeofStatement(Location loc, Statement value) {
-        super(loc);
-        this.value = value;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class TypeofStatement extends Statement {
+    public final Statement value;
+
+    // Not really pure, since a variable from the global scope could be accessed,
+    // which could lead to code execution, that would get omitted
+    @Override public boolean pure() { return true; }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        if (value instanceof VariableStatement) {
+            var i = scope.getKey(((VariableStatement)value).name);
+            if (i instanceof String) {
+                target.add(Instruction.typeof(loc(), (String)i));
+                return;
+            }
+        }
+        value.compile(target, scope, pollute);
+        target.add(Instruction.typeof(loc()));
+    }
+
+    public TypeofStatement(Location loc, Statement value) {
+        super(loc);
+        this.value = value;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/VariableAssignStatement.java

@@ -1,40 +1,38 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class VariableAssignStatement extends Statement {
-    public final String name;
-    public final Statement value;
-    public final Operation operation;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        var i = scope.getKey(name);
-        if (operation != null) {
-            target.add(Instruction.loadVar(i).locate(loc()));
-            if (value instanceof FunctionStatement) ((FunctionStatement)value).compile(target, scope, name, false);
-            else value.compile(target, scope, true);
-            target.add(Instruction.operation(operation).locate(loc()));
-            target.add(Instruction.storeVar(i, false).locate(loc()));
-        }
-        else {
-            if (value instanceof FunctionStatement) ((FunctionStatement)value).compile(target, scope, name, false);
-            else value.compile(target, scope, true);
-            target.add(Instruction.storeVar(i, false).locate(loc()));
-        }
-
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-
-    public VariableAssignStatement(Location loc, String name, Statement val, Operation operation) {
-        super(loc);
-        this.name = name;
-        this.value = val;
-        this.operation = operation;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class VariableAssignStatement extends Statement {
+    public final String name;
+    public final Statement value;
+    public final Operation operation;
+
+    @Override public boolean pure() { return false; }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        var i = scope.getKey(name);
+        if (operation != null) {
+            target.add(Instruction.loadVar(loc(), i));
+            FunctionStatement.compileWithName(value, target, scope, true, name);
+            target.add(Instruction.operation(loc(), operation));
+            target.add(Instruction.storeVar(loc(), i, pollute));
+        }
+        else {
+            FunctionStatement.compileWithName(value, target, scope, true, name);
+            target.add(Instruction.storeVar(loc(), i, pollute));
+        }
+    }
+
+    public VariableAssignStatement(Location loc, String name, Statement val, Operation operation) {
+        super(loc);
+        this.name = name;
+        this.value = val;
+        this.operation = operation;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/VariableIndexStatement.java

@@ -1,24 +1,23 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class VariableIndexStatement extends Statement {
-    public final int index;
-
-    @Override
-    public boolean pure() { return true; }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (pollute) target.add(Instruction.loadVar(index).locate(loc()));
-    }
-
-    public VariableIndexStatement(Location loc, int i) {
-        super(loc);
-        this.index = i;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class VariableIndexStatement extends Statement {
+    public final int index;
+
+    @Override public boolean pure() { return true; }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        if (pollute) target.add(Instruction.loadVar(loc(), index));
+    }
+
+    public VariableIndexStatement(Location loc, int i) {
+        super(loc);
+        this.index = i;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/VariableStatement.java

@@ -1,33 +1,32 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.AssignableStatement;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-
-public class VariableStatement extends AssignableStatement {
-    public final String name;
-
-    @Override
-    public boolean pure() { return true; }
-
-    @Override
-    public Statement toAssign(Statement val, Operation operation) {
-        return new VariableAssignStatement(loc(), name, val, operation);
-    }
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        var i = scope.getKey(name);
-        target.add(Instruction.loadVar(i).locate(loc()));
-        if (!pollute) target.add(Instruction.discard().locate(loc()));
-    }
-
-    public VariableStatement(Location loc, String name) {
-        super(loc);
-        this.name = name;
-    }
-}
+package me.topchetoeu.jscript.compilation.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.AssignableStatement;
+import me.topchetoeu.jscript.compilation.CompileTarget;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.compilation.Statement;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ScopeRecord;
+
+public class VariableStatement extends AssignableStatement {
+    public final String name;
+
+    @Override public boolean pure() { return false; }
+
+    @Override
+    public Statement toAssign(Statement val, Operation operation) {
+        return new VariableAssignStatement(loc(), name, val, operation);
+    }
+
+    @Override
+    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
+        var i = scope.getKey(name);
+        target.add(Instruction.loadVar(loc(), i));
+        if (!pollute) target.add(Instruction.discard(loc()));
+    }
+
+    public VariableStatement(Location loc, String name) {
+        super(loc);
+        this.name = name;
+    }
+}

src/me/topchetoeu/jscript/compilation/values/VoidStatement.java

@@ -1,30 +0,0 @@
-package me.topchetoeu.jscript.compilation.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.Statement;
-import me.topchetoeu.jscript.engine.scope.ScopeRecord;
-import me.topchetoeu.jscript.compilation.CompileTarget;
-import me.topchetoeu.jscript.compilation.Instruction;
-
-public class VoidStatement extends Statement {
-    public final Statement value;
-
-    @Override
-    public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        if (value != null) value.compile(target, scope, false);
-        if (pollute) target.add(Instruction.loadValue(null).locate(loc()));
-    }
-
-    @Override
-    public Statement optimize() {
-        if (value == null) return this;
-        var val = value.optimize();
-        if (val.pure()) return new ConstantStatement(loc(), null);
-        else return new VoidStatement(loc(), val);
-    }
-
-    public VoidStatement(Location loc, Statement value) {
-        super(loc);
-        this.value = value;
-    }
-}

src/me/topchetoeu/jscript/engine/Context.java

@@ -1,46 +1,164 @@
 package me.topchetoeu.jscript.engine;
 
-import java.util.Stack;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
 import java.util.TreeSet;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 
 import me.topchetoeu.jscript.Filename;
 import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.engine.debug.DebugContext;
+import me.topchetoeu.jscript.engine.frame.CodeFrame;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
 import me.topchetoeu.jscript.engine.values.FunctionValue;
+import me.topchetoeu.jscript.engine.values.Symbol;
 import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.parsing.Parsing;
+import me.topchetoeu.jscript.exceptions.EngineException;
+import me.topchetoeu.jscript.lib.EnvironmentLib;
+import me.topchetoeu.jscript.mapping.SourceMap;
 
-public class Context {
-    private final Stack<Environment> env = new Stack<>();
-    public final Data data;
+public class Context implements Extensions {
+    public final Context parent;
+    public final Environment environment;
+    public final CodeFrame frame;
     public final Engine engine;
+    public final int stackSize;
 
-    public Environment environment() {
-        return env.empty() ? null : env.peek();
+    @Override public <T> void add(Symbol key, T obj) {
+        if (environment != null) environment.add(key, obj);
+        else if (engine != null) engine.add(key, obj);
     }
+    @Override public <T> T get(Symbol key) {
+        if (environment != null && environment.has(key)) return environment.get(key);
+        else if (engine != null && engine.has(key)) return engine.get(key);
+        return null;
+    }
+    @Override public boolean has(Symbol key) {
+        return
+            environment != null && environment.has(key) ||
+            engine != null && engine.has(key);
+    }
+    @Override public boolean remove(Symbol key) {
+        var res = false;
 
-    public Context pushEnv(Environment env) {
-        this.env.push(env);
-        return this;
+        if (environment != null) res |= environment.remove(key);
+        else if (engine != null) res |= engine.remove(key);
+
+        return res;
     }
-    public void popEnv() {
-        if (!env.empty()) this.env.pop();
+    @Override public Iterable<Symbol> keys() {
+        if (engine == null && environment == null) return List.of();
+        if (engine == null) return environment.keys();
+        if (environment == null) return engine.keys();
+
+        return () -> Stream.concat(
+            StreamSupport.stream(engine.keys().spliterator(), false),
+            StreamSupport.stream(environment.keys().spliterator(), false)
+        ).distinct().iterator();
     }
 
     public FunctionValue compile(Filename filename, String raw) {
-        var src = Values.toString(this, environment().compile.call(this, null, raw, filename));
-        var debugger = StackData.getDebugger(this);
-        var breakpoints = new TreeSet<Location>();
-        var res = Parsing.compile(engine.functions, breakpoints, environment(), filename, src);
-        if (debugger != null) debugger.onSource(filename, src, breakpoints);
+        var env = environment;
+        var result = Environment.compileFunc(this).call(this, null, raw, filename.toString(), new EnvironmentLib(env));
+
+        var function = (FunctionValue)Values.getMember(this, result, "function");
+        if (!DebugContext.enabled(this)) return function;
+
+        var rawMapChain = ((ArrayValue)Values.getMember(this, result, "mapChain")).toArray();
+        var breakpoints = new TreeSet<>(
+            Arrays.stream(((ArrayValue)Values.getMember(this, result, "breakpoints")).toArray())
+                .map(v -> Location.parse(Values.toString(this, v)))
+                .collect(Collectors.toList())
+        );
+        var maps = new SourceMap[rawMapChain.length];
+
+        for (var i = 0; i < maps.length; i++) maps[i] = SourceMap.parse(Values.toString(this, (String)rawMapChain[i]));
+
+        var map = SourceMap.chain(maps);
+
+        if (map != null) {
+            var newBreakpoints = new TreeSet<Location>();
+            for (var bp : breakpoints) {
+                bp = map.toCompiled(bp);
+                if (bp != null) newBreakpoints.add(bp);
+            }
+            breakpoints = newBreakpoints;
+        }
+
+        DebugContext.get(this).onSource(filename, raw, breakpoints, map);
+
+        return function;
+    }
+
+    public Context pushFrame(CodeFrame frame) {
+        var res = new Context(this, frame.function.environment, frame, engine, stackSize + 1);
         return res;
     }
 
-    public Context(Engine engine, Data data) {
-        this.data = new Data(engine.data);
-        if (data != null) this.data.addAll(data);
-        this.engine = engine;
+    public Iterable<CodeFrame> frames() {
+        var self = this;
+        return () -> new Iterator<CodeFrame>() {
+            private Context curr = self;
+
+            private void update() {
+                while (curr != null && curr.frame == null) curr = curr.parent;
+            }
+
+            @Override public boolean hasNext() {
+                update();
+                return curr != null;
+            }
+            @Override public CodeFrame next() {
+                update();
+                var res = curr.frame;
+                curr = curr.parent;
+                return res;
+            }
+        };
     }
+    public List<String> stackTrace() {
+        var res = new ArrayList<String>();
+
+        for (var el : frames()) {
+            var name = el.function.name;
+            Location loc = null;
+
+            for (var j = el.codePtr; j >= 0 && loc == null; j--) loc = el.function.body[j].location;
+            if (loc == null) loc = el.function.loc();
+
+            var trace = "";
+
+            if (loc != null) trace += "at " + loc.toString() + " ";
+            if (name != null && !name.equals("")) trace += "in " + name + " ";
+
+            trace = trace.trim();
+
+            if (!trace.equals("")) res.add(trace);
+        }
+
+        return res;
+    }
+
+    private Context(Context parent, Environment environment, CodeFrame frame, Engine engine, int stackSize) {
+        this.parent = parent;
+        this.environment = environment;
+        this.frame = frame;
+        this.engine = engine;
+        this.stackSize = stackSize;
+
+        if (hasNotNull(Environment.MAX_STACK_COUNT) && stackSize > (int)get(Environment.MAX_STACK_COUNT)) {
+            throw EngineException.ofRange("Stack overflow!");
+        }
+    }
+
     public Context(Engine engine) {
-        this(engine, null);
+        this(null, null, null, engine, 0);
+    }
+    public Context(Engine engine, Environment env) {
+        this(null, env, null, engine, 0);
     }
 }

src/me/topchetoeu/jscript/engine/Data.java

@@ -1,71 +0,0 @@
-package me.topchetoeu.jscript.engine;
-
-import java.util.HashMap;
-import java.util.Map;
-
-@SuppressWarnings("unchecked")
-public class Data {
-    public final Data parent;
-    private HashMap<DataKey<Object>, Object> data = new HashMap<>();
-
-    public Data copy() {
-        return new Data().addAll(this);
-    }
-
-    public Data addAll(Map<DataKey<?>, ?> data) {
-        for (var el : data.entrySet()) {
-            get((DataKey<Object>)el.getKey(), (Object)el.getValue());
-        }
-        return this;
-    }
-    public Data addAll(Data data) {
-        for (var el : data.data.entrySet()) {
-            get((DataKey<Object>)el.getKey(), (Object)el.getValue());
-        }
-        return this;
-    }
-
-    public <T> T remove(DataKey<T> key) {
-        return (T)data.remove(key);
-    }
-    public <T> Data set(DataKey<T> key, T val) {
-        data.put((DataKey<Object>)key, (Object)val);
-        return this;
-    }
-    public <T> T get(DataKey<T> key, T val) {
-        for (var it = this; it != null; it = it.parent) {
-            if (it.data.containsKey(key)) {
-                return (T)it.data.get((DataKey<Object>)key);
-            }
-        }
-
-        set(key, val);
-        return val;
-    }
-    public <T> T get(DataKey<T> key) {
-        for (var it = this; it != null; it = it.parent) {
-            if (it.data.containsKey(key)) return (T)it.data.get((DataKey<Object>)key);
-        }
-        return null;
-    }
-    public boolean has(DataKey<?> key) { return data.containsKey(key); }
-
-    public int increase(DataKey<Integer> key, int n, int start) {
-        int res;
-        set(key, res = get(key, start) + n);
-        return res;
-    }
-    public int increase(DataKey<Integer> key, int n) {
-        return increase(key, n, 0);
-    }
-    public int increase(DataKey<Integer> key) {
-        return increase(key, 1, 0);
-    }
-
-    public Data() {
-        this.parent = null;
-    }
-    public Data(Data parent) {
-        this.parent = parent;
-    }
-}

src/me/topchetoeu/jscript/engine/DataKey.java

@@ -1,3 +0,0 @@
-package me.topchetoeu.jscript.engine;
-
-public class DataKey<T> { }

src/me/topchetoeu/jscript/engine/Engine.java

@@ -1,111 +1,57 @@
-package me.topchetoeu.jscript.engine;
-
-import java.util.HashMap;
-import java.util.concurrent.LinkedBlockingDeque;
-
-import me.topchetoeu.jscript.Filename;
-import me.topchetoeu.jscript.compilation.FunctionBody;
-import me.topchetoeu.jscript.engine.values.FunctionValue;
-import me.topchetoeu.jscript.events.Awaitable;
-import me.topchetoeu.jscript.events.DataNotifier;
-import me.topchetoeu.jscript.exceptions.InterruptException;
-
-public class Engine {
-    private class UncompiledFunction extends FunctionValue {
-        public final Filename filename;
-        public final String raw;
-        private FunctionValue compiled = null;
-
-        @Override
-        public Object call(Context ctx, Object thisArg, Object ...args) {
-            if (compiled == null) compiled = ctx.compile(filename, raw);
-            return compiled.call(ctx, thisArg, args);
-        }
-
-        public UncompiledFunction(Filename filename, String raw) {
-            super(filename + "", 0);
-            this.filename = filename;
-            this.raw = raw;
-        }
-    }
-
-    private static class Task {
-        public final FunctionValue func;
-        public final Object thisArg;
-        public final Object[] args;
-        public final DataNotifier<Object> notifier = new DataNotifier<>();
-        public final Context ctx;
-
-        public Task(Context ctx, FunctionValue func, Object thisArg, Object[] args) {
-            this.ctx = ctx;
-            this.func = func;
-            this.thisArg = thisArg;
-            this.args = args;
-        }
-    }
-
-    private static int nextId = 0;
-
-    private Thread thread;
-    private LinkedBlockingDeque<Task> macroTasks = new LinkedBlockingDeque<>();
-    private LinkedBlockingDeque<Task> microTasks = new LinkedBlockingDeque<>();
-
-    public final int id = ++nextId;
-    public final HashMap<Long, FunctionBody> functions = new HashMap<>();
-    public final Data data = new Data().set(StackData.MAX_FRAMES, 10000);
-
-    private void runTask(Task task) {
-        try {
-            task.notifier.next(task.func.call(task.ctx, task.thisArg, task.args));
-        }
-        catch (RuntimeException e) {
-            if (e instanceof InterruptException) throw e;
-            task.notifier.error(e);
-        }
-    }
-    public void run(boolean untilEmpty) {
-        while (!untilEmpty || !macroTasks.isEmpty()) {
-            try {
-                runTask(macroTasks.take());
-
-                while (!microTasks.isEmpty()) {
-                    runTask(microTasks.take());
-                }
-            }
-            catch (InterruptedException | InterruptException e) {
-                for (var msg : macroTasks) {
-                    msg.notifier.error(new InterruptException(e));
-                }
-                break;
-            }
-        }
-    }
-
-    public Thread start() {
-        if (this.thread == null) {
-            this.thread = new Thread(() -> run(false), "JavaScript Runner #" + id);
-            this.thread.start();
-        }
-        return this.thread;
-    }
-    public void stop() {
-        thread.interrupt();
-        thread = null;
-    }
-    public boolean inExecThread() {
-        return Thread.currentThread() == thread;
-    }
-    public boolean isRunning() {
-        return this.thread != null;
-    }
-
-    public Awaitable<Object> pushMsg(boolean micro, Context ctx, FunctionValue func, Object thisArg, Object ...args) {
-        var msg = new Task(ctx == null ? new Context(this) : ctx, func, thisArg, args);
-        if (micro) microTasks.addLast(msg);
-        else macroTasks.addLast(msg);
-        return msg.notifier;
-    }
-    public Awaitable<Object> pushMsg(boolean micro, Context ctx, Filename filename, String raw, Object thisArg, Object ...args) {
-        return pushMsg(micro, ctx, new UncompiledFunction(filename, raw), thisArg, args);
-    }
-}
+package me.topchetoeu.jscript.engine;
+
+import java.util.HashMap;
+
+import me.topchetoeu.jscript.Filename;
+import me.topchetoeu.jscript.compilation.FunctionBody;
+import me.topchetoeu.jscript.engine.values.FunctionValue;
+import me.topchetoeu.jscript.engine.values.Symbol;
+import me.topchetoeu.jscript.events.Awaitable;
+
+public class Engine extends EventLoop implements Extensions {
+    public static final HashMap<Long, FunctionBody> functions = new HashMap<>();
+
+    private final Environment env = new Environment();
+
+    @Override
+    public <T> void add(Symbol key, T obj) {
+        this.env.add(key, obj);
+    }
+    @Override
+    public <T> T get(Symbol key) {
+        return this.env.get(key);
+    }
+    @Override
+    public boolean has(Symbol key) {
+        return this.env.has(key);
+    }
+    @Override
+    public boolean remove(Symbol key) {
+        return this.env.remove(key);
+    }
+    @Override
+    public Iterable<Symbol> keys() {
+        return env.keys();
+    }
+
+    public Engine copy() {
+        var res = new Engine();
+        res.env.addAll(env);
+        return res;
+    }
+
+    public Awaitable<Object> pushMsg(boolean micro, Environment env, FunctionValue func, Object thisArg, Object ...args) {
+        return pushMsg(() -> {
+            return func.call(new Context(this, env), thisArg, args);
+        }, micro);
+    }
+    public Awaitable<Object> pushMsg(boolean micro, Environment env, Filename filename, String raw, Object thisArg, Object ...args) {
+        return pushMsg(() -> {
+            var ctx = new Context(this, env);
+            return ctx.compile(filename, raw).call(new Context(this, env), thisArg, args);
+        }, micro);
+    }
+
+    public Engine() {
+    }
+}

src/me/topchetoeu/jscript/engine/Environment.java

@@ -1,87 +1,128 @@
 package me.topchetoeu.jscript.engine;
 
 import java.util.HashMap;
+import java.util.stream.Collectors;
 
+import me.topchetoeu.jscript.Filename;
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.engine.debug.DebugContext;
 import me.topchetoeu.jscript.engine.scope.GlobalScope;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
 import me.topchetoeu.jscript.engine.values.FunctionValue;
 import me.topchetoeu.jscript.engine.values.NativeFunction;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
 import me.topchetoeu.jscript.engine.values.Symbol;
+import me.topchetoeu.jscript.engine.values.Values;
 import me.topchetoeu.jscript.exceptions.EngineException;
-import me.topchetoeu.jscript.interop.Native;
-import me.topchetoeu.jscript.interop.NativeGetter;
-import me.topchetoeu.jscript.interop.NativeSetter;
 import me.topchetoeu.jscript.interop.NativeWrapperProvider;
+import me.topchetoeu.jscript.parsing.Parsing;
 
-public class Environment {
-    private HashMap<String, ObjectValue> prototypes = new HashMap<>();
+@SuppressWarnings("unchecked")
+public class Environment implements Extensions {
 
-    public final Data data = new Data();
-    public final HashMap<String, Symbol> symbols = new HashMap<>();
+    public static final HashMap<String, Symbol> symbols = new HashMap<>();
+
+    public static final Symbol WRAPPERS = Symbol.get("Environment.wrappers");
+    public static final Symbol COMPILE_FUNC = Symbol.get("Environment.compile");
+
+    public static final Symbol REGEX_CONSTR = Symbol.get("Environment.regexConstructor");
+    public static final Symbol STACK = Symbol.get("Environment.stack");
+    public static final Symbol MAX_STACK_COUNT = Symbol.get("Environment.maxStackCount");
+    public static final Symbol HIDE_STACK = Symbol.get("Environment.hideStack");
+
+    public static final Symbol OBJECT_PROTO = Symbol.get("Environment.objectPrototype");
+    public static final Symbol FUNCTION_PROTO = Symbol.get("Environment.functionPrototype");
+    public static final Symbol ARRAY_PROTO = Symbol.get("Environment.arrayPrototype");
+    public static final Symbol BOOL_PROTO = Symbol.get("Environment.boolPrototype");
+    public static final Symbol NUMBER_PROTO = Symbol.get("Environment.numberPrototype");
+    public static final Symbol STRING_PROTO = Symbol.get("Environment.stringPrototype");
+    public static final Symbol SYMBOL_PROTO = Symbol.get("Environment.symbolPrototype");
+    public static final Symbol ERROR_PROTO = Symbol.get("Environment.errorPrototype");
+    public static final Symbol SYNTAX_ERR_PROTO = Symbol.get("Environment.syntaxErrorPrototype");
+    public static final Symbol TYPE_ERR_PROTO = Symbol.get("Environment.typeErrorPrototype");
+    public static final Symbol RANGE_ERR_PROTO = Symbol.get("Environment.rangeErrorPrototype");
+
+    private HashMap<Symbol, Object> data = new HashMap<>();
 
     public GlobalScope global;
     public WrappersProvider wrappers;
 
-    @Native public FunctionValue compile;
-    @Native public FunctionValue regexConstructor = new NativeFunction("RegExp", (ctx, thisArg, args) -> {
-        throw EngineException.ofError("Regular expressions not supported.").setCtx(ctx.environment(), ctx.engine);
-    });
-
-    public Environment addData(Data data) {
-        this.data.addAll(data);
-        return this;
+    @Override public <T> void add(Symbol key, T obj) {
+        data.put(key, obj);
     }
-
-    @Native public ObjectValue proto(String name) {
-        return prototypes.get(name);
+    @Override public <T> T get(Symbol key) {
+        return (T)data.get(key);
     }
-    @Native public void setProto(String name, ObjectValue val) {
-        prototypes.put(name, val);
-    }
-
-    @Native public Symbol symbol(String name) {
-        if (symbols.containsKey(name))
-            return symbols.get(name);
-        else {
-            var res = new Symbol(name);
-            symbols.put(name, res);
-            return res;
+    @Override public boolean remove(Symbol key) {
+        if (data.containsKey(key)) {
+            data.remove(key);
+            return true;
         }
+        return false;
+    }
+    @Override public boolean has(Symbol key) {
+        return data.containsKey(key);
+    }
+    @Override public Iterable<Symbol> keys() {
+        return data.keySet();
     }
 
-    @NativeGetter("global") public ObjectValue getGlobal() {
-        return global.obj;
+    public static FunctionValue compileFunc(Extensions ext) {
+        return ext.init(COMPILE_FUNC, new NativeFunction("compile", args -> {
+            var source = args.getString(0);
+            var filename = args.getString(1);
+            var env = Values.wrapper(args.convert(2, ObjectValue.class).getMember(args.ctx, Symbol.get("env")), Environment.class);
+            var isDebug = DebugContext.enabled(args.ctx);
+            var res = new ObjectValue();
+
+            var target = Parsing.compile(env, Filename.parse(filename), source);
+            Engine.functions.putAll(target.functions);
+            Engine.functions.remove(0l);
+
+            res.defineProperty(args.ctx, "function", target.func(env));
+            res.defineProperty(args.ctx, "mapChain", new ArrayValue());
+
+            if (isDebug) res.defineProperty(
+                args.ctx, "breakpoints",
+                ArrayValue.of(args.ctx, target.breakpoints.stream().map(Location::toString).collect(Collectors.toList()))
+            );
+
+            return res;
+        }));
     }
-    @NativeSetter("global") public void setGlobal(ObjectValue val) {
-        global = new GlobalScope(val);
+    public static FunctionValue regexConstructor(Extensions ext) {
+        return ext.init(COMPILE_FUNC, new NativeFunction("RegExp", args -> {
+            throw EngineException.ofError("Regular expressions not supported.").setCtx(args.ctx.environment, args.ctx.engine);
+        }));
     }
 
-    @Native public Environment fork() {
-        var res = new Environment(compile, wrappers, global);
-        res.regexConstructor = regexConstructor;
-        res.prototypes = new HashMap<>(prototypes);
+    public Environment copy() {
+        var res = new Environment(null, global);
+
+        res.wrappers = wrappers.fork(res);
+        res.global = global;
+        res.data.putAll(data);
+
         return res;
     }
-    @Native public Environment child() {
-        var res = fork();
+    public Environment child() {
+        var res = copy();
         res.global = res.global.globalChild();
         return res;
     }
 
-    public Context context(Engine engine, Data data) {
-        return new Context(engine, data).pushEnv(this);
-    }
     public Context context(Engine engine) {
-        return new Context(engine).pushEnv(this);
+        return new Context(engine, this);
     }
 
-    public Environment(FunctionValue compile, WrappersProvider nativeConverter, GlobalScope global) {
-        if (compile == null) compile = new NativeFunction("compile", (ctx, thisArg, args) -> args.length == 0 ? "" : args[0]);
+    public Environment(WrappersProvider nativeConverter, GlobalScope global) {
         if (nativeConverter == null) nativeConverter = new NativeWrapperProvider(this);
         if (global == null) global = new GlobalScope();
 
         this.wrappers = nativeConverter;
-        this.compile = compile;
         this.global = global;
     }
+    public Environment() {
+        this(null, null);
+    }
 }

src/me/topchetoeu/jscript/engine/EventLoop.java

@@ -0,0 +1,81 @@
+package me.topchetoeu.jscript.engine;
+
+import java.util.concurrent.PriorityBlockingQueue;
+
+import me.topchetoeu.jscript.ResultRunnable;
+import me.topchetoeu.jscript.events.Awaitable;
+import me.topchetoeu.jscript.events.DataNotifier;
+import me.topchetoeu.jscript.exceptions.InterruptException;
+
+public class EventLoop {
+    private static class Task implements Comparable<Task> {
+        public final ResultRunnable<?> runnable;
+        public final DataNotifier<Object> notifier = new DataNotifier<>();
+        public final boolean micro;
+
+        public Task(ResultRunnable<?> runnable, boolean micro) {
+            this.runnable = runnable;
+            this.micro = micro;
+        }
+
+        @Override
+        public int compareTo(Task other) {
+            return Integer.compare(this.micro ? 0 : 1, other.micro ? 0 : 1);
+        }
+    }
+
+    private PriorityBlockingQueue<Task> tasks = new PriorityBlockingQueue<>();
+    private Thread thread;
+
+    @SuppressWarnings("unchecked")
+    public <T> Awaitable<T> pushMsg(ResultRunnable<T> runnable, boolean micro) {
+        var msg = new Task(runnable, micro);
+        tasks.add(msg);
+        return (Awaitable<T>)msg.notifier;
+    }
+    public Awaitable<Object> pushMsg(Runnable runnable, boolean micro) {
+        return pushMsg(() -> { runnable.run(); return null; }, micro);
+    }
+
+    public void run(boolean untilEmpty) {
+        while (!untilEmpty || !tasks.isEmpty()) {
+            try {
+                var task = tasks.take();
+
+                try {
+                    task.notifier.next(task.runnable.run());
+                }
+                catch (RuntimeException e) {
+                    if (e instanceof InterruptException) throw e;
+                    task.notifier.error(e);
+                }
+            }
+            catch (InterruptedException | InterruptException e) {
+                for (var msg : tasks) msg.notifier.error(new InterruptException(e));
+                break;
+            }
+        }
+    }
+
+    public Thread thread() {
+        return thread;
+    }
+    public Thread start() {
+        if (thread == null) {
+            thread = new Thread(() -> run(false), "Event loop #" + hashCode());
+            thread.start();
+        }
+        return thread;
+    }
+    public void stop() {
+        if (thread != null) thread.interrupt();
+        thread = null;
+    }
+
+    public boolean inLoopThread() {
+        return Thread.currentThread() == thread;
+    }
+    public boolean isRunning() {
+        return this.thread != null;
+    }
+}

src/me/topchetoeu/jscript/engine/ExtensionStack.java

@@ -0,0 +1,39 @@
+package me.topchetoeu.jscript.engine;
+
+import me.topchetoeu.jscript.engine.values.Symbol;
+
+public abstract class ExtensionStack implements Extensions {
+    protected abstract Extensions[] extensionStack();
+
+    @Override public <T> void add(Symbol key, T obj) {
+        for (var el : extensionStack()) {
+            if (el != null) {
+                el.add(key, obj);
+                return;
+            }
+        }
+    }
+    @Override public <T> T get(Symbol key) {
+        for (var el : extensionStack()) {
+            if (el != null && el.has(key)) return el.get(key);
+        }
+
+        return null;
+    }
+    @Override public boolean has(Symbol key) {
+        for (var el : extensionStack()) {
+            if (el != null && el.has(key)) return true;
+        }
+
+        return false;
+    }
+    @Override public boolean remove(Symbol key) {
+        var anyRemoved = false;
+
+        for (var el : extensionStack()) {
+            if (el != null) anyRemoved &= el.remove(key);
+        }
+
+        return anyRemoved;
+    }
+}

src/me/topchetoeu/jscript/engine/Extensions.java

@@ -0,0 +1,34 @@
+package me.topchetoeu.jscript.engine;
+
+import me.topchetoeu.jscript.engine.values.Symbol;
+
+public interface Extensions {
+    <T> T get(Symbol key);
+    <T> void add(Symbol key, T obj);
+    Iterable<Symbol> keys();
+
+    boolean has(Symbol key);
+    boolean remove(Symbol key);
+
+    default boolean hasNotNull(Symbol key) {
+        return has(key) && get(key) != null;
+    }
+
+    default <T> T get(Symbol key, T defaultVal) {
+        if (has(key)) return get(key);
+        else return defaultVal;
+    }
+
+    default <T> T init(Symbol key, T val) {
+        if (has(key)) return get(key);
+        else {
+            add(key, val);
+            return val;
+        }
+    }
+    default void addAll(Extensions source) {
+        for (var key : source.keys()) {
+            add(key, source.get(key));
+        }
+    }
+}

src/me/topchetoeu/jscript/engine/StackData.java

@@ -1,65 +0,0 @@
-package me.topchetoeu.jscript.engine;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-import me.topchetoeu.jscript.engine.debug.Debugger;
-import me.topchetoeu.jscript.engine.frame.CodeFrame;
-import me.topchetoeu.jscript.exceptions.EngineException;
-
-public class StackData {
-    public static final DataKey<ArrayList<CodeFrame>> FRAMES = new DataKey<>();
-    public static final DataKey<Integer> MAX_FRAMES = new DataKey<>();
-    public static final DataKey<Debugger> DEBUGGER = new DataKey<>();
-
-    public static void pushFrame(Context ctx, CodeFrame frame) {
-        var frames = ctx.data.get(FRAMES, new ArrayList<>());
-        frames.add(frame);
-        if (frames.size() > ctx.data.get(MAX_FRAMES, 10000)) throw EngineException.ofRange("Stack overflow!");
-        ctx.pushEnv(frame.function.environment);
-    }
-    public static boolean popFrame(Context ctx, CodeFrame frame) {
-        var frames = ctx.data.get(FRAMES, new ArrayList<>());
-        if (frames.size() == 0) return false;
-        if (frames.get(frames.size() - 1) != frame) return false;
-        frames.remove(frames.size() - 1);
-        ctx.popEnv();
-        var dbg = getDebugger(ctx);
-        if (dbg != null) dbg.onFramePop(ctx, frame);
-        return true;
-    }
-    public static CodeFrame peekFrame(Context ctx) {
-        var frames = ctx.data.get(FRAMES, new ArrayList<>());
-        if (frames.size() == 0) return null;
-        return frames.get(frames.size() - 1);
-    }
-
-    public static List<CodeFrame> frames(Context ctx) {
-        return Collections.unmodifiableList(ctx.data.get(FRAMES, new ArrayList<>()));
-    }
-    public static List<String> stackTrace(Context ctx) {
-        var res = new ArrayList<String>();
-        var frames = frames(ctx);
-
-        for (var i = frames.size() - 1; i >= 0; i--) {
-            var el = frames.get(i);
-            var name = el.function.name;
-            var loc = el.function.loc();
-            var trace = "";
-
-            if (loc != null) trace += "at " + loc.toString() + " ";
-            if (name != null && !name.equals("")) trace += "in " + name + " ";
-
-            trace = trace.trim();
-
-            if (!trace.equals("")) res.add(trace);
-        }
-
-        return res;
-    }
-
-    public static Debugger getDebugger(Context ctx) {
-        return ctx.data.get(DEBUGGER);
-    }
-}

src/me/topchetoeu/jscript/engine/WrappersProvider.java

@@ -7,4 +7,6 @@ public interface WrappersProvider {
     public ObjectValue getProto(Class<?> obj);
     public ObjectValue getNamespace(Class<?> obj);
     public FunctionValue getConstr(Class<?> obj);
+
+    public WrappersProvider fork(Environment env);
 }

src/me/topchetoeu/jscript/engine/debug/DebugContext.java

@@ -0,0 +1,100 @@
+package me.topchetoeu.jscript.engine.debug;
+
+import java.util.HashMap;
+import java.util.TreeSet;
+
+import me.topchetoeu.jscript.Filename;
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.Extensions;
+import me.topchetoeu.jscript.engine.frame.CodeFrame;
+import me.topchetoeu.jscript.engine.values.Symbol;
+import me.topchetoeu.jscript.exceptions.EngineException;
+import me.topchetoeu.jscript.mapping.SourceMap;
+
+public class DebugContext implements DebugController {
+    public static final Symbol ENV_KEY = Symbol.get("Engine.debug");
+    public static final Symbol IGNORE = Symbol.get("Engine.ignoreDebug");
+
+    private HashMap<Filename, String> sources;
+    private HashMap<Filename, TreeSet<Location>> bpts;
+    private HashMap<Filename, SourceMap> maps;
+    private DebugController debugger;
+
+    public boolean attachDebugger(DebugController debugger) {
+        if (this.debugger != null) return false;
+
+        if (sources != null) {
+            for (var source : sources.entrySet()) debugger.onSource(
+                source.getKey(), source.getValue(),
+                bpts.get(source.getKey()),
+                maps.get(source.getKey())
+            );
+        }
+
+        this.debugger = debugger;
+        return true;
+    }
+    public boolean detachDebugger() {
+        this.debugger = null;
+        return true;
+    }
+
+    public DebugController debugger() {
+        if (debugger == null) return DebugController.empty();
+        else return debugger;
+    }
+
+    @Override public void onFramePop(Context ctx, CodeFrame frame) {
+        if (debugger != null) debugger.onFramePop(ctx, frame);
+    }
+    @Override public void onFramePush(Context ctx, CodeFrame frame) {
+        if (debugger != null) debugger.onFramePush(ctx, frame);
+    }
+    @Override public boolean onInstruction(Context ctx, CodeFrame frame, Instruction instruction, Object returnVal, EngineException error, boolean caught) {
+        if (debugger != null) return debugger.onInstruction(ctx, frame, instruction, returnVal, error, caught);
+        else return false;
+    }
+    @Override public void onSource(Filename filename, String source, TreeSet<Location> breakpoints, SourceMap map) {
+        if (debugger != null) debugger.onSource(filename, source, breakpoints, map);
+        if (sources != null) sources.put(filename, source);
+        if (bpts != null) bpts.put(filename, breakpoints);
+        if (maps != null) maps.put(filename, map);
+    }
+
+    public Location mapToCompiled(Location location) {
+        if (maps == null) return location;
+
+        var map = maps.get(location.filename());
+        if (map == null) return location;
+        return map.toCompiled(location);
+    }
+    public Location mapToOriginal(Location location) {
+        if (maps == null) return location;
+
+        var map = maps.get(location.filename());
+        if (map == null) return location;
+        return map.toOriginal(location);
+    }
+
+    private DebugContext(boolean enabled) {
+        if (enabled) {
+            sources = new HashMap<>();
+            bpts = new HashMap<>();
+            maps = new HashMap<>();
+        }
+    }
+
+    public DebugContext() {
+        this(true);
+    }
+
+    public static boolean enabled(Extensions exts) {
+        return exts.hasNotNull(ENV_KEY) && !exts.has(IGNORE);
+    }
+    public static DebugContext get(Extensions exts) {
+        if (enabled(exts)) return exts.get(ENV_KEY);
+        else return new DebugContext(false);
+    }
+}

src/me/topchetoeu/jscript/engine/debug/DebugController.java

@@ -8,13 +8,17 @@ import me.topchetoeu.jscript.compilation.Instruction;
 import me.topchetoeu.jscript.engine.Context;
 import me.topchetoeu.jscript.engine.frame.CodeFrame;
 import me.topchetoeu.jscript.exceptions.EngineException;
+import me.topchetoeu.jscript.mapping.SourceMap;
 
 public interface DebugController {
     /**
      * Called when a script has been loaded
-     * @param breakpoints 
+     * @param filename The name of the source
+     * @param source The name of the source
+     * @param breakpoints A set of all the breakpointable locations in this source
+     * @param map The source map associated with this file. null if this source map isn't mapped
      */
-    void onSource(Filename filename, String source, TreeSet<Location> breakpoints);
+    void onSource(Filename filename, String source, TreeSet<Location> breakpoints, SourceMap map);
 
     /**
      * Called immediatly before an instruction is executed, as well as after an instruction, if it has threw or returned.
@@ -23,13 +27,20 @@ public interface DebugController {
      * @param frame The frame in which execution is occuring
      * @param instruction The instruction which was or will be executed
      * @param loc The most recent location the code frame has been at
-     * @param returnVal The return value of the instruction, Runners.NO_RETURN if none
+     * @param returnVal The return value of the instruction, Values.NO_RETURN if none
      * @param error The error that the instruction threw, null if none
      * @param caught Whether or not the error has been caught
      * @return Whether or not the frame should restart
      */
     boolean onInstruction(Context ctx, CodeFrame frame, Instruction instruction, Object returnVal, EngineException error, boolean caught);
 
+    /**
+     * Called immediatly before a frame has been pushed on the frame stack.
+     * This function might pause in order to await debugging commands.
+     * @param ctx The context of execution
+     * @param frame The code frame which was pushed
+     */
+    void onFramePush(Context ctx, CodeFrame frame);
     /**
      * Called immediatly after a frame has been popped out of the frame stack.
      * This function might pause in order to await debugging commands.
@@ -38,6 +49,14 @@ public interface DebugController {
      */
     void onFramePop(Context ctx, CodeFrame frame);
 
-    void connect();
-    void disconnect();
+    public static DebugController empty() {
+        return new DebugController () {
+            @Override public void onFramePop(Context ctx, CodeFrame frame) { }
+            @Override public void onFramePush(Context ctx, CodeFrame frame) { }
+            @Override public boolean onInstruction(Context ctx, CodeFrame frame, Instruction instruction, Object returnVal, EngineException error, boolean caught) {
+                return false;
+            }
+            @Override public void onSource(Filename filename, String source, TreeSet<Location> breakpoints, SourceMap map) { }
+        };
+    }
 }

src/me/topchetoeu/jscript/engine/debug/DebugHandler.java

@@ -1,35 +1,33 @@
 package me.topchetoeu.jscript.engine.debug;
 
+import java.io.IOException;
+
 public interface DebugHandler {
-    void enable(V8Message msg);
-    void disable(V8Message msg);
+    void enable(V8Message msg) throws IOException;
+    void disable(V8Message msg) throws IOException;
 
-    void setBreakpoint(V8Message msg);
-    void setBreakpointByUrl(V8Message msg);
-    void removeBreakpoint(V8Message msg);
-    void continueToLocation(V8Message msg);
+    void setBreakpointByUrl(V8Message msg) throws IOException;
+    void removeBreakpoint(V8Message msg) throws IOException;
+    void continueToLocation(V8Message msg) throws IOException;
 
-    void getScriptSource(V8Message msg);
-    void getPossibleBreakpoints(V8Message msg);
+    void getScriptSource(V8Message msg) throws IOException;
+    void getPossibleBreakpoints(V8Message msg) throws IOException;
 
-    void resume(V8Message msg);
-    void pause(V8Message msg);
+    void resume(V8Message msg) throws IOException;
+    void pause(V8Message msg) throws IOException;
 
-    void stepInto(V8Message msg);
-    void stepOut(V8Message msg);
-    void stepOver(V8Message msg);
+    void stepInto(V8Message msg) throws IOException;
+    void stepOut(V8Message msg) throws IOException;
+    void stepOver(V8Message msg) throws IOException;
 
-    void setPauseOnExceptions(V8Message msg);
+    void setPauseOnExceptions(V8Message msg) throws IOException;
 
-    void evaluateOnCallFrame(V8Message msg);
+    void evaluateOnCallFrame(V8Message msg) throws IOException;
 
-    void getProperties(V8Message msg);
-    void releaseObjectGroup(V8Message msg);
-    /**
-     * This method might not execute the actual code for well-known requests
-     */
-    void callFunctionOn(V8Message msg);
+    void getProperties(V8Message msg) throws IOException;
+    void releaseObjectGroup(V8Message msg) throws IOException;
+    void releaseObject(V8Message msg) throws IOException;
+    void callFunctionOn(V8Message msg) throws IOException;
 
-    // void nodeWorkerEnable(V8Message msg);
-    void runtimeEnable(V8Message msg);
+    void runtimeEnable(V8Message msg) throws IOException;
 }

src/me/topchetoeu/jscript/engine/debug/DebugServer.java

@@ -1,6 +1,7 @@
 package me.topchetoeu.jscript.engine.debug;
 
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
@@ -9,20 +10,21 @@ import java.util.Base64;
 import java.util.HashMap;
 
 import me.topchetoeu.jscript.Metadata;
+import me.topchetoeu.jscript.Reading;
 import me.topchetoeu.jscript.engine.debug.WebSocketMessage.Type;
+import me.topchetoeu.jscript.events.Notifier;
 import me.topchetoeu.jscript.exceptions.SyntaxException;
-import me.topchetoeu.jscript.exceptions.UncheckedException;
-import me.topchetoeu.jscript.exceptions.UncheckedIOException;
 import me.topchetoeu.jscript.json.JSON;
 import me.topchetoeu.jscript.json.JSONList;
 import me.topchetoeu.jscript.json.JSONMap;
 
 public class DebugServer {
-    public static String browserDisplayName = Metadata.NAME + "/" + Metadata.VERSION;
+    public static String browserDisplayName = Metadata.name() + "/" + Metadata.version();
 
     public final HashMap<String, DebuggerProvider> targets = new HashMap<>();
 
     private final byte[] favicon, index, protocol;
+    private final Notifier connNotifier = new Notifier();
 
     private static void send(HttpRequest req, String val) throws IOException {
         req.writeResponse(200, "OK", "application/json", val.getBytes());
@@ -33,8 +35,7 @@ public class DebugServer {
         try {
             return MessageDigest.getInstance("sha1");
         }
-        catch (Throwable e) { throw new UncheckedException(e); }
-
+        catch (Throwable e) { throw new RuntimeException(e); }
     }
 
     private static Thread runAsync(Runnable func, String name) {
@@ -44,11 +45,9 @@ public class DebugServer {
         return res;
     }
 
-    private void handle(WebSocket ws, Debugger debugger) {
+    private void handle(WebSocket ws, Debugger debugger) throws IOException {
         WebSocketMessage raw;
 
-        debugger.connect();
-
         while ((raw = ws.receive()) != null) {
             if (raw.type != Type.Text) {
                 ws.send(new V8Error("Expected a text message."));
@@ -59,60 +58,56 @@ public class DebugServer {
 
             try {
                 msg = new V8Message(raw.textData());
-                // System.out.println(msg.name + ": " + JSON.stringify(msg.params));
             }
             catch (SyntaxException e) {
                 ws.send(new V8Error(e.getMessage()));
                 return;
             }
 
-            try {
-                switch (msg.name) {
-                    case "Debugger.enable": debugger.enable(msg); continue;
-                    case "Debugger.disable": debugger.disable(msg); continue;
+            switch (msg.name) {
+                case "Debugger.enable":
+                    connNotifier.next();
+                    debugger.enable(msg);
+                    continue;
+                case "Debugger.disable": debugger.close(); continue;
 
-                    case "Debugger.setBreakpoint": debugger.setBreakpoint(msg); continue;
-                    case "Debugger.setBreakpointByUrl": debugger.setBreakpointByUrl(msg); continue;
-                    case "Debugger.removeBreakpoint": debugger.removeBreakpoint(msg); continue;
-                    case "Debugger.continueToLocation": debugger.continueToLocation(msg); continue;
+                case "Debugger.setBreakpointByUrl": debugger.setBreakpointByUrl(msg); continue;
+                case "Debugger.removeBreakpoint": debugger.removeBreakpoint(msg); continue;
+                case "Debugger.continueToLocation": debugger.continueToLocation(msg); continue;
 
-                    case "Debugger.getScriptSource": debugger.getScriptSource(msg); continue;
-                    case "Debugger.getPossibleBreakpoints": debugger.getPossibleBreakpoints(msg); continue;
+                case "Debugger.getScriptSource": debugger.getScriptSource(msg); continue;
+                case "Debugger.getPossibleBreakpoints": debugger.getPossibleBreakpoints(msg); continue;
 
-                    case "Debugger.resume": debugger.resume(msg); continue;
-                    case "Debugger.pause": debugger.pause(msg); continue;
+                case "Debugger.resume": debugger.resume(msg); continue;
+                case "Debugger.pause": debugger.pause(msg); continue;
 
-                    case "Debugger.stepInto": debugger.stepInto(msg); continue;
-                    case "Debugger.stepOut": debugger.stepOut(msg); continue;
-                    case "Debugger.stepOver": debugger.stepOver(msg); continue;
+                case "Debugger.stepInto": debugger.stepInto(msg); continue;
+                case "Debugger.stepOut": debugger.stepOut(msg); continue;
+                case "Debugger.stepOver": debugger.stepOver(msg); continue;
 
-                    case "Debugger.setPauseOnExceptions": debugger.setPauseOnExceptions(msg); continue;
-                    case "Debugger.evaluateOnCallFrame": debugger.evaluateOnCallFrame(msg); continue;
+                case "Debugger.setPauseOnExceptions": debugger.setPauseOnExceptions(msg); continue;
+                case "Debugger.evaluateOnCallFrame": debugger.evaluateOnCallFrame(msg); continue;
 
-                    case "Runtime.releaseObjectGroup": debugger.releaseObjectGroup(msg); continue;
-                    case "Runtime.getProperties": debugger.getProperties(msg); continue;
-                    case "Runtime.callFunctionOn": debugger.callFunctionOn(msg); continue;
-                    // case "NodeWorker.enable": debugger.nodeWorkerEnable(msg); continue;
-                    case "Runtime.enable": debugger.runtimeEnable(msg); continue;
-                }
-
-                if (
-                    msg.name.startsWith("DOM.") ||
-                    msg.name.startsWith("DOMDebugger.") ||
-                    msg.name.startsWith("Emulation.") ||
-                    msg.name.startsWith("Input.") ||
-                    msg.name.startsWith("Network.") ||
-                    msg.name.startsWith("Page.")
-                ) ws.send(new V8Error("This isn't a browser..."));
-                else ws.send(new V8Error("This API is not supported yet."));
-            }
-            catch (Throwable e) {
-                e.printStackTrace();
-                throw new UncheckedException(e);
+                case "Runtime.releaseObjectGroup": debugger.releaseObjectGroup(msg); continue;
+                case "Runtime.releaseObject": debugger.releaseObject(msg); continue;
+                case "Runtime.getProperties": debugger.getProperties(msg); continue;
+                case "Runtime.callFunctionOn": debugger.callFunctionOn(msg); continue;
+                // case "NodeWorker.enable": debugger.nodeWorkerEnable(msg); continue;
+                case "Runtime.enable": debugger.runtimeEnable(msg); continue;
             }
+
+            if (
+                msg.name.startsWith("DOM.") ||
+                msg.name.startsWith("DOMDebugger.") ||
+                msg.name.startsWith("Emulation.") ||
+                msg.name.startsWith("Input.") ||
+                msg.name.startsWith("Network.") ||
+                msg.name.startsWith("Page.")
+            ) ws.send(new V8Error("This isn't a browser..."));
+            else ws.send(new V8Error("This API is not supported yet."));
         }
 
-        debugger.disconnect();
+        debugger.close();
     }
     private void onWsConnect(HttpRequest req, Socket socket, DebuggerProvider debuggerProvider) {
         var key = req.headers.get("sec-websocket-key");
@@ -144,13 +139,20 @@ public class DebugServer {
 
         runAsync(() -> {
             try { handle(ws, debugger); }
-            catch (RuntimeException e) {
-                ws.send(new V8Error(e.getMessage()));
+            catch (RuntimeException | IOException e) {
+                try {
+                    ws.send(new V8Error(e.getMessage()));
+                }
+                catch (IOException e2) { /* Shit outta luck */ }
             }
-            finally { ws.close(); debugger.disconnect(); }
+            finally { ws.close(); debugger.close(); }
         }, "Debug Handler");
     }
 
+    public void awaitConnection() {
+        connNotifier.await();
+    }
+
     public void run(InetSocketAddress address) {
         try {
             ServerSocket server = new ServerSocket();
@@ -224,15 +226,16 @@ public class DebugServer {
 
     public DebugServer() {
         try {
-            this.favicon = getClass().getClassLoader().getResourceAsStream("assets/favicon.png").readAllBytes();
-            this.protocol = getClass().getClassLoader().getResourceAsStream("assets/protocol.json").readAllBytes();
-            var index = new String(getClass().getClassLoader().getResourceAsStream("assets/index.html").readAllBytes());
-            this.index = index
-                .replace("${NAME}", Metadata.NAME)
-                .replace("${VERSION}", Metadata.VERSION)
-                .replace("${AUTHOR}", Metadata.AUTHOR)
+            this.favicon = Reading.resourceToStream("assets/debugger/favicon.png").readAllBytes();
+            this.protocol = Reading.resourceToStream("assets/debugger/protocol.json").readAllBytes();
+            this.index = Reading.resourceToString("assets/debugger/index.html")
+                .replace("${NAME}", Metadata.name())
+                .replace("${VERSION}", Metadata.version())
+                .replace("${AUTHOR}", Metadata.author())
                 .getBytes();
         }
-        catch (IOException e) { throw new UncheckedIOException(e); }
+        catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
     }
 }

src/me/topchetoeu/jscript/engine/debug/Debugger.java

@@ -1,5 +1,5 @@
 package me.topchetoeu.jscript.engine.debug;
 
 public interface Debugger extends DebugHandler, DebugController {
-    
+    void close();
 }

src/me/topchetoeu/jscript/engine/debug/V8Message.java

@@ -2,7 +2,6 @@ package me.topchetoeu.jscript.engine.debug;
 
 import java.util.Map;
 
-import me.topchetoeu.jscript.Filename;
 import me.topchetoeu.jscript.json.JSON;
 import me.topchetoeu.jscript.json.JSONElement;
 import me.topchetoeu.jscript.json.JSONMap;
@@ -33,7 +32,7 @@ public class V8Message {
         this.params = raw.contains("params") ? raw.map("params") : new JSONMap();
     }
     public V8Message(String raw) {
-        this(JSON.parse(new Filename("jscript", "json-msg"), raw).map());
+        this(JSON.parse(null, raw).map());
     }
 
     public JSONMap toMap() {

src/me/topchetoeu/jscript/engine/debug/WebSocket.java

@@ -7,108 +7,102 @@ import java.io.OutputStream;
 import java.net.Socket;
 
 import me.topchetoeu.jscript.engine.debug.WebSocketMessage.Type;
-import me.topchetoeu.jscript.exceptions.UncheckedIOException;
 
 public class WebSocket implements AutoCloseable {
-    public long maxLength = 2000000;
+    public long maxLength = 1 << 20;
 
     private Socket socket;
     private boolean closed = false;
 
-    private OutputStream out() {
-        try { return socket.getOutputStream(); }
-        catch (IOException e) { throw new UncheckedIOException(e); }
+    private OutputStream out() throws IOException {
+        return socket.getOutputStream();
     }
-    private InputStream in() {
-        try { return socket.getInputStream(); }
-        catch (IOException e) { throw new UncheckedIOException(e); }
+    private InputStream in() throws IOException {
+        return socket.getInputStream();
     }
 
-    private long readLen(int byteLen) {
+    private long readLen(int byteLen) throws IOException {
         long res = 0;
 
-        try {
-            if (byteLen == 126) {
-                res |= in().read() << 8;
-                res |= in().read();
-                return res;
-            }
-            else if (byteLen == 127) {
-                res |= in().read() << 56;
-                res |= in().read() << 48;
-                res |= in().read() << 40;
-                res |= in().read() << 32;
-                res |= in().read() << 24;
-                res |= in().read() << 16;
-                res |= in().read() << 8;
-                res |= in().read();
-                return res;
-            }
-            else return byteLen;
+        if (byteLen == 126) {
+            res |= in().read() << 8;
+            res |= in().read();
+            return res;
         }
-        catch (IOException e) { throw new UncheckedIOException(e); }
+        else if (byteLen == 127) {
+            res |= in().read() << 56;
+            res |= in().read() << 48;
+            res |= in().read() << 40;
+            res |= in().read() << 32;
+            res |= in().read() << 24;
+            res |= in().read() << 16;
+            res |= in().read() << 8;
+            res |= in().read();
+            return res;
+        }
+        else return byteLen;
     }
-    private byte[] readMask(boolean has) {
+    private byte[] readMask(boolean has) throws IOException {
         if (has) {
-            try { return new byte[] {
+            return new byte[] {
                 (byte)in().read(),
                 (byte)in().read(),
                 (byte)in().read(),
                 (byte)in().read()
-            }; }
-            catch (IOException e) { throw new UncheckedIOException(e); }
+            };
         }
         else return new byte[4];
     }
 
-    private void writeLength(long len) {
-        try {
-            if (len < 126) {
-                out().write((int)len);
-            }
-            else if (len < 0xFFFF) {
-                out().write(126);
-                out().write((int)(len >> 8) & 0xFF);
-                out().write((int)len & 0xFF);
-            }
-            else {
-                out().write(127);
-                out().write((int)(len >> 56) & 0xFF);
-                out().write((int)(len >> 48) & 0xFF);
-                out().write((int)(len >> 40) & 0xFF);
-                out().write((int)(len >> 32) & 0xFF);
-                out().write((int)(len >> 24) & 0xFF);
-                out().write((int)(len >> 16) & 0xFF);
-                out().write((int)(len >> 8) & 0xFF);
-                out().write((int)len & 0xFF);
-            }
+    private void writeLength(int len) throws IOException {
+        if (len < 126) {
+            out().write((int)len);
+        }
+        else if (len <= 0xFFFF) {
+            out().write(126);
+            out().write((int)(len >> 8) & 0xFF);
+            out().write((int)len & 0xFF);
+        }
+        else {
+            out().write(127);
+            out().write((len >> 56) & 0xFF);
+            out().write((len >> 48) & 0xFF);
+            out().write((len >> 40) & 0xFF);
+            out().write((len >> 32) & 0xFF);
+            out().write((len >> 24) & 0xFF);
+            out().write((len >> 16) & 0xFF);
+            out().write((len >> 8) & 0xFF);
+            out().write(len & 0xFF);
         }
-        catch (IOException e) { throw new UncheckedIOException(e); }
     }
-    private synchronized void write(int type, byte[] data) {
-        try {
-            out().write(type | 0x80);
-            writeLength(data.length);
-            for (int i = 0; i < data.length; i++) {
-                out().write(data[i]);
-            }
+    private synchronized void write(int type, byte[] data) throws IOException {
+        int i;
+
+        for (i = 0; i < data.length / 0xFFFF; i++) {
+            out().write(type);
+            writeLength(0xFFFF);
+            out().write(data, i * 0xFFFF, 0xFFFF);
+            type = 0;
         }
-        catch (IOException e) { throw new UncheckedIOException(e); }
+
+        out().write(type | 0x80);
+        writeLength(data.length % 0xFFFF);
+        out().write(data, i * 0xFFFF, data.length % 0xFFFF);
     }
 
-    public void send(String data) {
+    public void send(String data) throws IOException {
         if (closed) throw new IllegalStateException("Object is closed.");
         write(1, data.getBytes());
     }
-    public void send(byte[] data) {
+    public void send(byte[] data) throws IOException {
         if (closed) throw new IllegalStateException("Object is closed.");
         write(2, data);
     }
-    public void send(WebSocketMessage msg) {
+    public void send(WebSocketMessage msg) throws IOException {
         if (msg.type == Type.Binary) send(msg.binaryData());
         else send(msg.textData());
     }
-    public void send(Object data) {
+    public void send(Object data) throws IOException {
         if (closed) throw new IllegalStateException("Object is closed.");
         write(1, data.toString().getBytes());
     }
@@ -135,67 +129,59 @@ public class WebSocket implements AutoCloseable {
         return null;
     }
 
-    private byte[] readData() {
-        try {
-            var maskLen = in().read();
-            var hasMask = (maskLen & 0x80) != 0;
-            var len = (int)readLen(maskLen & 0x7F);
-            var mask = readMask(hasMask);
-    
-            if (len > maxLength) fail("WebSocket Error: client exceeded configured max message size");
-            else {
-                var buff = new byte[len];
-    
-                if (in().read(buff) < len) fail("WebSocket Error: payload too short");
-                else {
-                    for (int i = 0; i < len; i++) {
-                        buff[i] ^= mask[(int)(i % 4)];
-                    }
-                    return buff;
-                }
-            }
+    private byte[] readData() throws IOException {
+        var maskLen = in().read();
+        var hasMask = (maskLen & 0x80) != 0;
+        var len = (int)readLen(maskLen & 0x7F);
+        var mask = readMask(hasMask);
 
-            return null;
+        if (len > maxLength) fail("WebSocket Error: client exceeded configured max message size");
+        else {
+            var buff = new byte[len];
+
+            if (in().read(buff) < len) fail("WebSocket Error: payload too short");
+            else {
+                for (int i = 0; i < len; i++) {
+                    buff[i] ^= mask[(int)(i % 4)];
+                }
+                return buff;
+            }
         }
-        catch (IOException e) { throw new UncheckedIOException(e); }
+
+        return null;
     }
 
-    public WebSocketMessage receive() {
-        try {
-            var data = new ByteArrayOutputStream();
-            var type = 0;
+    public WebSocketMessage receive() throws IOException {
+        var data = new ByteArrayOutputStream();
+        var type = 0;
 
-            while (socket != null && !closed) {
-                var finId = in().read();
-                if (finId < 0) break;
-                var fin = (finId & 0x80) != 0;
-                int id = finId & 0x0F;
+        while (socket != null && !closed) {
+            var finId = in().read();
+            if (finId < 0) break;
+            var fin = (finId & 0x80) != 0;
+            int id = finId & 0x0F;
 
-                if (id == 0x8) { close(); return null; }
-                if (id >= 0x8) {
-                    if (!fin) return fail("WebSocket Error: client-sent control frame was fragmented");
-                    if (id == 0x9) write(0xA, data.toByteArray());
-                    continue;
-                }
-
-                if (type == 0) type = id;
-                if (type == 0) return fail("WebSocket Error: client used opcode 0x00 for first fragment");
-
-                var buff = readData();
-                if (buff == null) break;
-
-                if (data.size() + buff.length > maxLength) return fail("WebSocket Error: client exceeded configured max message size");
-                data.write(buff);
-
-                if (!fin) continue;
-                var raw = data.toByteArray();
-
-                if (type == 1) return new WebSocketMessage(new String(raw));
-                else return new WebSocketMessage(raw);
+            if (id == 0x8) { close(); return null; }
+            if (id >= 0x8) {
+                if (!fin) return fail("WebSocket Error: client-sent control frame was fragmented");
+                if (id == 0x9) write(0xA, data.toByteArray());
+                continue;
             }
-        }
-        catch (IOException e) {
-            close();
+
+            if (type == 0) type = id;
+            if (type == 0) return fail("WebSocket Error: client used opcode 0x00 for first fragment");
+
+            var buff = readData();
+            if (buff == null) break;
+
+            if (data.size() + buff.length > maxLength) return fail("WebSocket Error: client exceeded configured max message size");
+            data.write(buff);
+
+            if (!fin) continue;
+            var raw = data.toByteArray();
+
+            if (type == 1) return new WebSocketMessage(new String(raw));
+            else return new WebSocketMessage(raw);
         }
 
         return null;

src/me/topchetoeu/jscript/engine/frame/CodeFrame.java

@@ -1,281 +1,332 @@
-package me.topchetoeu.jscript.engine.frame;
-
-import java.util.Stack;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.StackData;
-import me.topchetoeu.jscript.engine.scope.LocalScope;
-import me.topchetoeu.jscript.engine.scope.ValueVariable;
-import me.topchetoeu.jscript.engine.values.ArrayValue;
-import me.topchetoeu.jscript.engine.values.CodeFunction;
-import me.topchetoeu.jscript.engine.values.ObjectValue;
-import me.topchetoeu.jscript.engine.values.ScopeValue;
-import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.exceptions.EngineException;
-import me.topchetoeu.jscript.exceptions.InterruptException;
-
-public class CodeFrame {
-    private class TryCtx {
-        public static final int STATE_TRY = 0;
-        public static final int STATE_CATCH = 1;
-        public static final int STATE_FINALLY_THREW = 2;
-        public static final int STATE_FINALLY_RETURNED = 3;
-        public static final int STATE_FINALLY_JUMPED = 4;
-
-        public final boolean hasCatch, hasFinally;
-        public final int tryStart, catchStart, finallyStart, end;
-        public int state;
-        public Object retVal;
-        public EngineException err;
-        public int jumpPtr;
-
-        public TryCtx(int tryStart, int tryN, int catchN, int finallyN) {
-            hasCatch = catchN >= 0;
-            hasFinally = finallyN >= 0;
-
-            if (catchN < 0) catchN = 0;
-            if (finallyN < 0) finallyN = 0;
-
-            this.tryStart = tryStart;
-            this.catchStart = tryStart + tryN;
-            this.finallyStart = catchStart + catchN;
-            this.end = finallyStart + finallyN;
-            this.jumpPtr = end;
-        }
-    }
-
-    public final LocalScope scope;
-    public final Object thisArg;
-    public final Object[] args;
-    public final Stack<TryCtx> tryStack = new Stack<>();
-    public final CodeFunction function;
-
-    public Object[] stack = new Object[32];
-    public int stackPtr = 0;
-    public int codePtr = 0;
-    public boolean jumpFlag = false;
-    private Location prevLoc = null;
-
-    public ObjectValue getLocalScope(Context ctx, boolean props) {
-        var names = new String[scope.locals.length];
-
-        for (int i = 0; i < scope.locals.length; i++) {
-            var name = "local_" + (i - 2);
-
-            if (i == 0) name = "this";
-            else if (i == 1) name = "arguments";
-            else if (i < function.localNames.length) name = function.localNames[i];
-
-            names[i] = name;
-        }
-
-        return new ScopeValue(scope.locals, names);
-    }
-    public ObjectValue getCaptureScope(Context ctx, boolean props) {
-        var names = new String[scope.captures.length];
-
-        for (int i = 0; i < scope.captures.length; i++) {
-            var name = "capture_" + (i - 2);
-            if (i < function.captureNames.length) name = function.captureNames[i];
-            names[i] = name;
-        }
-
-        return new ScopeValue(scope.captures, names);
-    }
-
-    public void addTry(int n, int catchN, int finallyN) {
-        var res = new TryCtx(codePtr + 1, n, catchN, finallyN);
-
-        tryStack.add(res);
-    }
-
-    public Object peek() {
-        return peek(0);
-    }
-    public Object peek(int offset) {
-        if (stackPtr <= offset) return null;
-        else return stack[stackPtr - 1 - offset];
-    }
-    public Object pop() {
-        if (stackPtr == 0) return null;
-        return stack[--stackPtr];
-    }
-    public Object[] take(int n) {
-        int srcI = stackPtr - n;
-        if (srcI < 0) srcI = 0;
-
-        int dstI = n + srcI - stackPtr;
-        int copyN = stackPtr - srcI;
-
-        Object[] res = new Object[n];
-        System.arraycopy(stack, srcI, res, dstI, copyN);
-        stackPtr -= copyN;
-
-        return res;
-    }
-    public void push(Context ctx, Object val) {
-        if (stack.length <= stackPtr) {
-            var newStack = new Object[stack.length * 2];
-            System.arraycopy(stack, 0, newStack, 0, stack.length);
-            stack = newStack;
-        }
-        stack[stackPtr++] = Values.normalize(ctx, val);
-    }
-
-    private void setCause(Context ctx, EngineException err, EngineException cause) {
-        err.cause = cause;
-    }
-    private Object nextNoTry(Context ctx, Instruction instr) {
-        if (Thread.currentThread().isInterrupted()) throw new InterruptException();
-        if (codePtr < 0 || codePtr >= function.body.length) return null;
-
-        try {
-            this.jumpFlag = false;
-            return Runners.exec(ctx, instr, this);
-        }
-        catch (EngineException e) {
-            throw e.add(function.name, prevLoc).setCtx(function.environment, ctx.engine);
-        }
-    }
-
-    public Object next(Context ctx, Object value, Object returnValue, EngineException error) {
-        if (value != Runners.NO_RETURN) push(ctx, value);
-        var debugger = StackData.getDebugger(ctx);
-
-        if (returnValue == Runners.NO_RETURN && error == null) {
-            try {
-                var instr = function.body[codePtr];
-
-                if (debugger != null) debugger.onInstruction(ctx, this, instr, Runners.NO_RETURN, null, false);
-                returnValue = nextNoTry(ctx, instr);
-            }
-            catch (EngineException e) { error = e; }
-        }
-
-        while (!tryStack.empty()) {
-            var tryCtx = tryStack.peek();
-            var newState = -1;
-
-            switch (tryCtx.state) {
-                case TryCtx.STATE_TRY:
-                    if (error != null) {
-                        if (tryCtx.hasCatch) {
-                            tryCtx.err = error;
-                            newState = TryCtx.STATE_CATCH;
-                        }
-                        else if (tryCtx.hasFinally) {
-                            tryCtx.err = error;
-                            newState = TryCtx.STATE_FINALLY_THREW;
-                        }
-                        break;
-                    }
-                    else if (returnValue != Runners.NO_RETURN) {
-                        if (tryCtx.hasFinally) {
-                            tryCtx.retVal = returnValue;
-                            newState = TryCtx.STATE_FINALLY_RETURNED;
-                        }
-                        break;
-                    }
-                    else if (codePtr >= tryCtx.tryStart && codePtr < tryCtx.catchStart) return Runners.NO_RETURN;
-
-                    if (tryCtx.hasFinally) {
-                        if (jumpFlag) tryCtx.jumpPtr = codePtr;
-                        else tryCtx.jumpPtr = tryCtx.end;
-                        newState = TryCtx.STATE_FINALLY_JUMPED;
-                    }
-                    else codePtr = tryCtx.end;
-                    break;
-                case TryCtx.STATE_CATCH:
-                    if (error != null) {
-                        if (tryCtx.hasFinally) {
-                            tryCtx.err = error;
-                            newState = TryCtx.STATE_FINALLY_THREW;
-                        }
-                        setCause(ctx, error, tryCtx.err);
-                        break;
-                    }
-                    else if (returnValue != Runners.NO_RETURN) {
-                        if (tryCtx.hasFinally) {
-                            tryCtx.retVal = returnValue;
-                            newState = TryCtx.STATE_FINALLY_RETURNED;
-                        }
-                        break;
-                    }
-                    else if (codePtr >= tryCtx.catchStart && codePtr < tryCtx.finallyStart) return Runners.NO_RETURN;
-
-                    if (tryCtx.hasFinally) {
-                        if (jumpFlag) tryCtx.jumpPtr = codePtr;
-                        else tryCtx.jumpPtr = tryCtx.end;
-                        newState = TryCtx.STATE_FINALLY_JUMPED;
-                    }
-                    else codePtr = tryCtx.end;
-                    break;
-                case TryCtx.STATE_FINALLY_THREW:
-                    if (error != null) setCause(ctx, error, tryCtx.err);
-                    else if (codePtr < tryCtx.finallyStart || codePtr >= tryCtx.end) error = tryCtx.err;
-                    else return Runners.NO_RETURN;
-                    break;
-                case TryCtx.STATE_FINALLY_RETURNED:
-                    if (returnValue == Runners.NO_RETURN) {
-                        if (codePtr < tryCtx.finallyStart || codePtr >= tryCtx.end) returnValue = tryCtx.retVal;
-                        else return Runners.NO_RETURN;
-                    }
-                    break;
-                case TryCtx.STATE_FINALLY_JUMPED:
-                    if (codePtr < tryCtx.finallyStart || codePtr >= tryCtx.end) {
-                        if (!jumpFlag) codePtr = tryCtx.jumpPtr;
-                        else codePtr = tryCtx.end;
-                    }
-                    else return Runners.NO_RETURN;
-                    break;
-            }
-
-            if (tryCtx.state == TryCtx.STATE_CATCH) scope.catchVars.remove(scope.catchVars.size() - 1);
-
-            if (newState == -1) {
-                tryStack.pop();
-                continue;
-            }
-
-            tryCtx.state = newState;
-            switch (newState) {
-                case TryCtx.STATE_CATCH:
-                    scope.catchVars.add(new ValueVariable(false, tryCtx.err.value));
-                    codePtr = tryCtx.catchStart;
-                    if (debugger != null) debugger.onInstruction(ctx, this, function.body[codePtr], null, error, true);
-                    break;
-                default:
-                    codePtr = tryCtx.finallyStart;
-            }
-
-            return Runners.NO_RETURN;
-        }
-    
-        if (error != null) {
-            if (debugger != null) debugger.onInstruction(ctx, this, function.body[codePtr], null, error, false);
-            throw error;
-        }
-        if (returnValue != Runners.NO_RETURN) {
-            if (debugger != null) debugger.onInstruction(ctx, this, function.body[codePtr], returnValue, null, false);
-            return returnValue;
-        }
-
-        return Runners.NO_RETURN;
-    }
-
-    public CodeFrame(Context ctx, Object thisArg, Object[] args, CodeFunction func) {
-        this.args = args.clone();
-        this.scope = new LocalScope(func.localsN, func.captures);
-        this.scope.get(0).set(null, thisArg);
-        var argsObj = new ArrayValue();
-        for (var i = 0; i < args.length; i++) {
-            argsObj.set(ctx, i, args[i]);
-        }
-        this.scope.get(1).value = argsObj;
-
-        this.thisArg = thisArg;
-        this.function = func;
-    }
-}
+package me.topchetoeu.jscript.engine.frame;
+
+import java.util.List;
+import java.util.Stack;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.debug.DebugContext;
+import me.topchetoeu.jscript.engine.scope.LocalScope;
+import me.topchetoeu.jscript.engine.scope.ValueVariable;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
+import me.topchetoeu.jscript.engine.values.CodeFunction;
+import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.ScopeValue;
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.exceptions.EngineException;
+import me.topchetoeu.jscript.exceptions.InterruptException;
+
+public class CodeFrame {
+    public static enum TryState {
+        TRY,
+        CATCH,
+        FINALLY,
+    }
+
+    public static class TryCtx {
+        public final int start, end, catchStart, finallyStart;
+        public final int restoreStackPtr;
+        public final TryState state;
+        public final EngineException error;
+        public final PendingResult result;
+
+        public boolean hasCatch() { return catchStart >= 0; }
+        public boolean hasFinally() { return finallyStart >= 0; }
+
+        public boolean inBounds(int ptr) {
+            return ptr >= start && ptr < end;
+        }
+
+        public void setCause(EngineException target) {
+            if (error != null) target.setCause(error);
+        }
+        public TryCtx _catch(EngineException e) {
+            return new TryCtx(TryState.CATCH, e, result, restoreStackPtr, start, end, -1, finallyStart);
+        }
+        public TryCtx _finally(PendingResult res) {
+            return new TryCtx(TryState.FINALLY, error, res, restoreStackPtr, start, end, -1, -1);
+        }
+
+        public TryCtx(TryState state, EngineException err, PendingResult res, int stackPtr, int start, int end, int catchStart, int finallyStart) {
+            this.catchStart = catchStart;
+            this.finallyStart = finallyStart;
+            this.restoreStackPtr = stackPtr;
+            this.result = res == null ? PendingResult.ofNone() : res;
+            this.state = state;
+            this.start = start;
+            this.end = end;
+            this.error = err;
+        }
+    }
+
+    private static class PendingResult {
+        public final boolean isReturn, isJump, isThrow;
+        public final Object value;
+        public final EngineException error;
+        public final int ptr;
+        public final Instruction instruction;
+
+        private PendingResult(Instruction instr, boolean isReturn, boolean isJump, boolean isThrow, Object value, EngineException error, int ptr) {
+            this.instruction = instr;
+            this.isReturn = isReturn;
+            this.isJump = isJump;
+            this.isThrow = isThrow;
+            this.value = value;
+            this.error = error;
+            this.ptr = ptr;
+        }
+
+        public static PendingResult ofNone() {
+            return new PendingResult(null, false, false, false, null, null, 0);
+        }
+        public static PendingResult ofReturn(Object value, Instruction instr) {
+            return new PendingResult(instr, true, false, false, value, null, 0);
+        }
+        public static PendingResult ofThrow(EngineException error, Instruction instr) {
+            return new PendingResult(instr, false, false, true, null, error, 0);
+        }
+        public static PendingResult ofJump(int codePtr, Instruction instr) {
+            return new PendingResult(instr, false, true, false, null, null, codePtr);
+        }
+    }
+
+    public final LocalScope scope;
+    public final Object thisArg;
+    public final Object[] args;
+    public final Stack<TryCtx> tryStack = new Stack<>();
+    public final CodeFunction function;
+    public final Context ctx;
+    public Object[] stack = new Object[32];
+    public int stackPtr = 0;
+    public int codePtr = 0;
+    public boolean jumpFlag = false, popTryFlag = false;
+    private Location prevLoc = null;
+
+    public ObjectValue getLocalScope(boolean props) {
+        var names = new String[scope.locals.length];
+
+        for (int i = 0; i < scope.locals.length; i++) {
+            var name = "local_" + (i - 2);
+
+            if (i == 0) name = "this";
+            else if (i == 1) name = "arguments";
+            else if (i < function.localNames.length) name = function.localNames[i];
+
+            names[i] = name;
+        }
+
+        return new ScopeValue(scope.locals, names);
+    }
+    public ObjectValue getCaptureScope(boolean props) {
+        var names = new String[scope.captures.length];
+
+        for (int i = 0; i < scope.captures.length; i++) {
+            var name = "capture_" + (i - 2);
+            if (i < function.captureNames.length) name = function.captureNames[i];
+            names[i] = name;
+        }
+
+        return new ScopeValue(scope.captures, names);
+    }
+    public ObjectValue getValStackScope() {
+        return new ObjectValue() {
+            @Override
+            protected Object getField(Context ctx, Object key) {
+                var i = (int)Values.toNumber(ctx, key);
+                if (i < 0 || i >= stackPtr) return null;
+                else return stack[i];
+            }
+            @Override
+            protected boolean hasField(Context ctx, Object key) {
+                return true;
+            }
+            @Override
+            public List<Object> keys(boolean includeNonEnumerable) {
+                var res = super.keys(includeNonEnumerable);
+                for (var i = 0; i < stackPtr; i++) res.add(i);
+                return res;
+            }
+        };
+    }
+
+    public void addTry(int start, int end, int catchStart, int finallyStart) {
+        var err = tryStack.empty() ? null : tryStack.peek().error;
+        var res = new TryCtx(TryState.TRY, err, null, stackPtr, start, end, catchStart, finallyStart);
+
+        tryStack.add(res);
+    }
+
+    public Object peek() {
+        return peek(0);
+    }
+    public Object peek(int offset) {
+        if (stackPtr <= offset) return null;
+        else return stack[stackPtr - 1 - offset];
+    }
+    public Object pop() {
+        if (stackPtr == 0) return null;
+        return stack[--stackPtr];
+    }
+    public Object[] take(int n) {
+        int srcI = stackPtr - n;
+        if (srcI < 0) srcI = 0;
+
+        int dstI = n + srcI - stackPtr;
+        int copyN = stackPtr - srcI;
+
+        Object[] res = new Object[n];
+        System.arraycopy(stack, srcI, res, dstI, copyN);
+        stackPtr -= copyN;
+
+        return res;
+    }
+    public void push(Object val) {
+        if (stack.length <= stackPtr) {
+            var newStack = new Object[stack.length * 2];
+            System.arraycopy(stack, 0, newStack, 0, stack.length);
+            stack = newStack;
+        }
+        stack[stackPtr++] = Values.normalize(ctx, val);
+    }
+
+    public Object next(Object value, Object returnValue, EngineException error) {
+        if (value != Values.NO_RETURN) push(value);
+
+        Instruction instr = null;
+        if (codePtr >= 0 && codePtr < function.body.length) instr = function.body[codePtr];
+
+        if (returnValue == Values.NO_RETURN && error == null) {
+            try {
+                if (Thread.currentThread().isInterrupted()) throw new InterruptException();
+
+                if (instr == null) returnValue = null;
+                else {
+                    DebugContext.get(ctx).onInstruction(ctx, this, instr, Values.NO_RETURN, null, false);
+
+                    if (instr.location != null) prevLoc = instr.location;
+
+                    try {
+                        this.jumpFlag = this.popTryFlag = false;
+                        returnValue = Runners.exec(ctx, instr, this);
+                    }
+                    catch (EngineException e) {
+                        error = e.add(ctx, function.name, prevLoc);
+                    }
+                }
+            }
+            catch (EngineException e) { error = e; }
+        }
+
+        while (!tryStack.empty()) {
+            var tryCtx = tryStack.peek();
+            TryCtx newCtx = null;
+
+            if (error != null) {
+                tryCtx.setCause(error);
+                if (tryCtx.hasCatch()) newCtx = tryCtx._catch(error);
+                else if (tryCtx.hasFinally()) newCtx = tryCtx._finally(PendingResult.ofThrow(error, instr));
+            }
+            else if (returnValue != Values.NO_RETURN) {
+                if (tryCtx.hasFinally()) newCtx = tryCtx._finally(PendingResult.ofReturn(returnValue, instr));
+            }
+            else if (jumpFlag && !tryCtx.inBounds(codePtr)) {
+                if (tryCtx.hasFinally()) newCtx = tryCtx._finally(PendingResult.ofJump(codePtr, instr));
+            }
+            else if (!this.popTryFlag) newCtx = tryCtx;
+
+            if (newCtx != null) {
+                if (newCtx != tryCtx) {
+                    switch (newCtx.state) {
+                        case CATCH:
+                            if (tryCtx.state != TryState.CATCH) scope.catchVars.add(new ValueVariable(false, error.value));
+                            codePtr = tryCtx.catchStart;
+                            stackPtr = tryCtx.restoreStackPtr;
+                            break;
+                        case FINALLY:
+                            if (tryCtx.state == TryState.CATCH) scope.catchVars.remove(scope.catchVars.size() - 1);
+                            codePtr = tryCtx.finallyStart;
+                            stackPtr = tryCtx.restoreStackPtr;
+                        default:
+                    }
+
+                    tryStack.pop();
+                    tryStack.push(newCtx);
+                }
+                error = null;
+                returnValue = Values.NO_RETURN;
+                break;
+            }
+            else {
+                popTryFlag = false;
+                if (tryCtx.state == TryState.CATCH) scope.catchVars.remove(scope.catchVars.size() - 1);
+
+                if (tryCtx.state != TryState.FINALLY && tryCtx.hasFinally()) {
+                    codePtr = tryCtx.finallyStart;
+                    stackPtr = tryCtx.restoreStackPtr;
+                    tryStack.pop();
+                    tryStack.push(tryCtx._finally(null));
+                    break;
+                }
+                else {
+                    tryStack.pop();
+                    codePtr = tryCtx.end;
+                    if (tryCtx.result.instruction != null) instr = tryCtx.result.instruction;
+                    if (!jumpFlag && returnValue == Values.NO_RETURN && error == null) {
+                        if (tryCtx.result.isJump) {
+                            codePtr = tryCtx.result.ptr;
+                            jumpFlag = true;
+                        }
+                        if (tryCtx.result.isReturn) returnValue = tryCtx.result.value;
+                        if (error == null && tryCtx.result.isThrow) {
+                            error = tryCtx.result.error;
+                        }
+                    }
+                    if (error != null) tryCtx.setCause(error);
+                    continue;
+                }
+            }
+        }
+
+        if (error != null) {
+            var caught = false;
+
+            for (var frame : ctx.frames()) {
+                for (var tryCtx : frame.tryStack) {
+                    if (tryCtx.state == TryState.TRY) caught = true;
+                }
+            }
+
+            DebugContext.get(ctx).onInstruction(ctx, this, instr, null, error, caught);
+            throw error;
+        }
+        if (returnValue != Values.NO_RETURN) {
+            DebugContext.get(ctx).onInstruction(ctx, this, instr, returnValue, null, false);
+            return returnValue;
+        }
+
+        return Values.NO_RETURN;
+    }
+
+    public void onPush() {
+        DebugContext.get(ctx).onFramePush(ctx, this);
+    }
+    public void onPop() {
+        DebugContext.get(ctx.parent).onFramePop(ctx.parent, this);
+    }
+
+    public CodeFrame(Context ctx, Object thisArg, Object[] args, CodeFunction func) {
+        this.args = args.clone();
+        this.scope = new LocalScope(func.localsN, func.captures);
+        this.scope.get(0).set(null, thisArg);
+        var argsObj = new ArrayValue();
+        for (var i = 0; i < args.length; i++) {
+            argsObj.set(ctx, i, args[i]);
+        }
+        this.scope.get(1).value = argsObj;
+
+        this.thisArg = thisArg;
+        this.function = func;
+        this.ctx = ctx.pushFrame(this);
+    }
+}

src/me/topchetoeu/jscript/engine/frame/ConvertHint.java

@@ -1,6 +1,6 @@
-package me.topchetoeu.jscript.engine.frame;
-
-public enum ConvertHint {
-    TOSTRING,
-    VALUEOF,
+package me.topchetoeu.jscript.engine.frame;
+
+public enum ConvertHint {
+    TOSTRING,
+    VALUEOF,
 }

src/me/topchetoeu/jscript/engine/frame/InstructionResult.java

@@ -1,9 +1,9 @@
-package me.topchetoeu.jscript.engine.frame;
-
-public class InstructionResult {
-    public final Object value;
-
-    public InstructionResult(Object value) {
-        this.value = value;
-    }
-}
+package me.topchetoeu.jscript.engine.frame;
+
+public class InstructionResult {
+    public final Object value;
+
+    public InstructionResult(Object value) {
+        this.value = value;
+    }
+}

src/me/topchetoeu/jscript/engine/frame/Runners.java

@@ -1,371 +1,355 @@
-package me.topchetoeu.jscript.engine.frame;
-
-import java.util.Collections;
-
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Operation;
-import me.topchetoeu.jscript.engine.scope.ValueVariable;
-import me.topchetoeu.jscript.engine.values.ArrayValue;
-import me.topchetoeu.jscript.engine.values.CodeFunction;
-import me.topchetoeu.jscript.engine.values.ObjectValue;
-import me.topchetoeu.jscript.engine.values.Symbol;
-import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.exceptions.EngineException;
-
-public class Runners {
-    public static final Object NO_RETURN = new Object();
-
-    public static Object execReturn(Context ctx, Instruction instr, CodeFrame frame) {
-        return frame.pop();
-    }
-    public static Object execThrow(Context ctx, Instruction instr, CodeFrame frame) {
-        throw new EngineException(frame.pop());
-    }
-    public static Object execThrowSyntax(Context ctx, Instruction instr, CodeFrame frame) {
-        throw EngineException.ofSyntax((String)instr.get(0));
-    }
-
-    private static Object call(Context ctx, Object func, Object thisArg, Object ...args) {
-        return Values.call(ctx, func, thisArg, args);
-    }
-
-    public static Object execCall(Context ctx, Instruction instr, CodeFrame frame) {
-        var callArgs = frame.take(instr.get(0));
-        var func = frame.pop();
-        var thisArg = frame.pop();
-
-        frame.push(ctx, call(ctx, func, thisArg, callArgs));
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execCallNew(Context ctx, Instruction instr, CodeFrame frame) {
-        var callArgs = frame.take(instr.get(0));
-        var funcObj = frame.pop();
-
-        frame.push(ctx, Values.callNew(ctx, funcObj, callArgs));
-
-        // if (Values.isFunction(funcObj) && Values.function(funcObj).special) {
-        //     frame.push(ctx, call(ctx, funcObj, null, callArgs));
-        // }
-        // else {
-        //     var proto = Values.getMember(ctx, funcObj, "prototype");
-        //     var obj = new ObjectValue();
-        //     obj.setPrototype(ctx, proto);
-        //     call(ctx, funcObj, obj, callArgs);
-        //     frame.push(ctx, obj);
-        // }
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-
-    public static Object execMakeVar(Context ctx, Instruction instr, CodeFrame frame) {
-        var name = (String)instr.get(0);
-        ctx.environment().global.define(name);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execDefProp(Context ctx, Instruction instr, CodeFrame frame) {
-        var setter = frame.pop();
-        var getter = frame.pop();
-        var name = frame.pop();
-        var obj = frame.pop();
-
-        if (getter != null && !Values.isFunction(getter)) throw EngineException.ofType("Getter must be a function or undefined.");
-        if (setter != null && !Values.isFunction(setter)) throw EngineException.ofType("Setter must be a function or undefined.");
-        if (!Values.isObject(obj)) throw EngineException.ofType("Property apply target must be an object.");
-        Values.object(obj).defineProperty(ctx, name, Values.function(getter), Values.function(setter), false, false);
-
-        frame.push(ctx, obj);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execInstanceof(Context ctx, Instruction instr, CodeFrame frame) {
-        var type = frame.pop();
-        var obj = frame.pop();
-
-        if (!Values.isPrimitive(type)) {
-            var proto = Values.getMember(ctx, type, "prototype");
-            frame.push(ctx, Values.isInstanceOf(ctx, obj, proto));
-        }
-        else {
-            frame.push(ctx, false);
-        }
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execKeys(Context ctx, Instruction instr, CodeFrame frame) {
-        var val = frame.pop();
-
-        var arr = new ObjectValue();
-        var i = 0;
-
-        var members = Values.getMembers(ctx, val, false, false);
-        Collections.reverse(members);
-        for (var el : members) {
-            if (el instanceof Symbol) continue;
-            arr.defineProperty(ctx, i++, el);
-        }
-
-        arr.defineProperty(ctx, "length", i);
-
-        frame.push(ctx, arr);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-
-    public static Object execTry(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.addTry(instr.get(0), instr.get(1), instr.get(2));
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-
-    public static Object execDup(Context ctx, Instruction instr, CodeFrame frame) {
-        int offset = instr.get(0), count = instr.get(1);
-
-        for (var i = 0; i < count; i++) {
-            frame.push(ctx, frame.peek(offset + count - 1));
-        }
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execMove(Context ctx, Instruction instr, CodeFrame frame) {
-        int offset = instr.get(0), count = instr.get(1);
-
-        var tmp = frame.take(offset);
-        var res = frame.take(count);
-
-        for (var i = 0; i < offset; i++) frame.push(ctx, tmp[i]);
-        for (var i = 0; i < count; i++) frame.push(ctx, res[i]);
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadUndefined(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.push(ctx, null);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadValue(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.push(ctx, instr.get(0));
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadVar(Context ctx, Instruction instr, CodeFrame frame) {
-        var i = instr.get(0);
-
-        if (i instanceof String) frame.push(ctx, ctx.environment().global.get(ctx, (String)i));
-        else frame.push(ctx, frame.scope.get((int)i).get(ctx));
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadObj(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.push(ctx, new ObjectValue());
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadGlob(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.push(ctx, ctx.environment().global.obj);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadArr(Context ctx, Instruction instr, CodeFrame frame) {
-        var res = new ArrayValue();
-        res.setSize(instr.get(0));
-        frame.push(ctx, res);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadFunc(Context ctx, Instruction instr, CodeFrame frame) {
-        long id = (Long)instr.get(0);
-        int localsN = (Integer)instr.get(1);
-        int len = (Integer)instr.get(2);
-        var captures = new ValueVariable[instr.params.length - 3];
-
-        for (var i = 3; i < instr.params.length; i++) {
-            captures[i - 3] = frame.scope.get(instr.get(i));
-        }
-
-        var body = ctx.engine.functions.get(id);
-        var func = new CodeFunction(ctx.environment(), "", localsN, len, captures, body);
-
-        frame.push(ctx, func);
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadMember(Context ctx, Instruction instr, CodeFrame frame) {
-        var key = frame.pop();
-        var obj = frame.pop();
-
-        try {
-            frame.push(ctx, Values.getMember(ctx, obj, key));
-        }
-        catch (IllegalArgumentException e) {
-            throw EngineException.ofType(e.getMessage());
-        }
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execLoadKeyMember(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.push(ctx, instr.get(0));
-        return execLoadMember(ctx, instr, frame);
-    }
-    public static Object execLoadRegEx(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.push(ctx, ctx.environment().regexConstructor.call(ctx, null, instr.get(0), instr.get(1)));
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-
-    public static Object execDiscard(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.pop();
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execStoreMember(Context ctx, Instruction instr, CodeFrame frame) {
-        var val = frame.pop();
-        var key = frame.pop();
-        var obj = frame.pop();
-
-        if (!Values.setMember(ctx, obj, key, val)) throw EngineException.ofSyntax("Can't set member '" + key + "'.");
-        if ((boolean)instr.get(0)) frame.push(ctx, val);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execStoreVar(Context ctx, Instruction instr, CodeFrame frame) {
-        var val = (boolean)instr.get(1) ? frame.peek() : frame.pop();
-        var i = instr.get(0);
-
-        if (i instanceof String) ctx.environment().global.set(ctx, (String)i, val);
-        else frame.scope.get((int)i).set(ctx, val);
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execStoreSelfFunc(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.scope.locals[(int)instr.get(0)].set(ctx, frame.function);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    
-    public static Object execJmp(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.codePtr += (int)instr.get(0);
-        frame.jumpFlag = true;
-        return NO_RETURN;
-    }
-    public static Object execJmpIf(Context ctx, Instruction instr, CodeFrame frame) {
-        if (Values.toBoolean(frame.pop())) {
-            frame.codePtr += (int)instr.get(0);
-            frame.jumpFlag = true;
-        }
-        else frame.codePtr ++;
-        return NO_RETURN;
-    }
-    public static Object execJmpIfNot(Context ctx, Instruction instr, CodeFrame frame) {
-        if (Values.not(frame.pop())) {
-            frame.codePtr += (int)instr.get(0);
-            frame.jumpFlag = true;
-        }
-        else frame.codePtr ++;
-        return NO_RETURN;
-    }
-
-    public static Object execIn(Context ctx, Instruction instr, CodeFrame frame) {
-        var obj = frame.pop();
-        var index = frame.pop();
-
-        frame.push(ctx, Values.hasMember(ctx, obj, index, false));
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execTypeof(Context ctx, Instruction instr, CodeFrame frame) {
-        String name = instr.get(0);
-        Object obj;
-
-        if (name != null) {
-            if (ctx.environment().global.has(ctx, name)) {
-                obj = ctx.environment().global.get(ctx, name);
-            }
-            else obj = null;
-        }
-        else obj = frame.pop();
-
-        frame.push(ctx, Values.type(obj));
-
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-    public static Object execNop(Context ctx, Instruction instr, CodeFrame frame) {
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-
-    public static Object execDelete(Context ctx, Instruction instr, CodeFrame frame) {
-        var key = frame.pop();
-        var val = frame.pop();
-
-        if (!Values.deleteMember(ctx, val, key)) throw EngineException.ofSyntax("Can't delete member '" + key + "'.");
-        frame.push(ctx, true);
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-
-    public static Object execOperation(Context ctx, Instruction instr, CodeFrame frame) {
-        Operation op = instr.get(0);
-        var args = new Object[op.operands];
-
-        for (var i = op.operands - 1; i >= 0; i--) args[i] = frame.pop();
-
-        frame.push(ctx, Values.operation(ctx, op, args));
-        frame.codePtr++;
-        return NO_RETURN;
-    }
-
-    public static Object exec(Context ctx, Instruction instr, CodeFrame frame) {
-        switch (instr.type) {
-            case NOP: return execNop(ctx, instr, frame);
-            case RETURN: return execReturn(ctx, instr, frame);
-            case THROW: return execThrow(ctx, instr, frame);
-            case THROW_SYNTAX: return execThrowSyntax(ctx, instr, frame);
-            case CALL: return execCall(ctx, instr, frame);
-            case CALL_NEW: return execCallNew(ctx, instr, frame);
-            case TRY: return execTry(ctx, instr, frame);
-
-            case DUP: return execDup(ctx, instr, frame);
-            case MOVE: return execMove(ctx, instr, frame);
-            case LOAD_VALUE: return execLoadValue(ctx, instr, frame);
-            case LOAD_VAR: return execLoadVar(ctx, instr, frame);
-            case LOAD_OBJ: return execLoadObj(ctx, instr, frame);
-            case LOAD_ARR: return execLoadArr(ctx, instr, frame);
-            case LOAD_FUNC: return execLoadFunc(ctx, instr, frame);
-            case LOAD_MEMBER: return execLoadMember(ctx, instr, frame);
-            case LOAD_VAL_MEMBER: return execLoadKeyMember(ctx, instr, frame);
-            case LOAD_REGEX: return execLoadRegEx(ctx, instr, frame);
-            case LOAD_GLOB: return execLoadGlob(ctx, instr, frame);
-
-            case DISCARD: return execDiscard(ctx, instr, frame);
-            case STORE_MEMBER: return execStoreMember(ctx, instr, frame);
-            case STORE_VAR: return execStoreVar(ctx, instr, frame);
-            case STORE_SELF_FUNC: return execStoreSelfFunc(ctx, instr, frame);
-            case MAKE_VAR: return execMakeVar(ctx, instr, frame);
-
-            case KEYS: return execKeys(ctx, instr, frame);
-            case DEF_PROP: return execDefProp(ctx, instr, frame);
-            case TYPEOF: return execTypeof(ctx, instr, frame);
-            case DELETE: return execDelete(ctx, instr, frame);
-
-            case JMP: return execJmp(ctx, instr, frame);
-            case JMP_IF: return execJmpIf(ctx, instr, frame);
-            case JMP_IFN: return execJmpIfNot(ctx, instr, frame);
-
-            case OPERATION: return execOperation(ctx, instr, frame);
-
-            default: throw EngineException.ofSyntax("Invalid instruction " + instr.type.name() + ".");
-        }
-    }
-}
+package me.topchetoeu.jscript.engine.frame;
+
+import java.util.Collections;
+
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.Engine;
+import me.topchetoeu.jscript.engine.Environment;
+import me.topchetoeu.jscript.engine.Operation;
+import me.topchetoeu.jscript.engine.scope.ValueVariable;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
+import me.topchetoeu.jscript.engine.values.CodeFunction;
+import me.topchetoeu.jscript.engine.values.FunctionValue;
+import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.Symbol;
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.exceptions.EngineException;
+
+public class Runners {
+    public static Object execReturn(Context ctx, Instruction instr, CodeFrame frame) {
+        return frame.pop();
+    }
+    public static Object execThrow(Context ctx, Instruction instr, CodeFrame frame) {
+        throw new EngineException(frame.pop());
+    }
+    public static Object execThrowSyntax(Context ctx, Instruction instr, CodeFrame frame) {
+        throw EngineException.ofSyntax((String)instr.get(0));
+    }
+
+    public static Object execCall(Context ctx, Instruction instr, CodeFrame frame) {
+        var callArgs = frame.take(instr.get(0));
+        var func = frame.pop();
+        var thisArg = frame.pop();
+
+        frame.push(Values.call(ctx, func, thisArg, callArgs));
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execCallNew(Context ctx, Instruction instr, CodeFrame frame) {
+        var callArgs = frame.take(instr.get(0));
+        var funcObj = frame.pop();
+
+        frame.push(Values.callNew(ctx, funcObj, callArgs));
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+
+    public static Object execMakeVar(Context ctx, Instruction instr, CodeFrame frame) {
+        var name = (String)instr.get(0);
+        ctx.environment.global.define(name);
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execDefProp(Context ctx, Instruction instr, CodeFrame frame) {
+        var setter = frame.pop();
+        var getter = frame.pop();
+        var name = frame.pop();
+        var obj = frame.pop();
+
+        if (getter != null && !(getter instanceof FunctionValue)) throw EngineException.ofType("Getter must be a function or undefined.");
+        if (setter != null && !(setter instanceof FunctionValue)) throw EngineException.ofType("Setter must be a function or undefined.");
+        if (!(obj instanceof ObjectValue)) throw EngineException.ofType("Property apply target must be an object.");
+        Values.object(obj).defineProperty(ctx, name, Values.function(getter), Values.function(setter), false, false);
+
+        frame.push(obj);
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execInstanceof(Context ctx, Instruction instr, CodeFrame frame) {
+        var type = frame.pop();
+        var obj = frame.pop();
+
+        if (!Values.isPrimitive(type)) {
+            var proto = Values.getMember(ctx, type, "prototype");
+            frame.push(Values.isInstanceOf(ctx, obj, proto));
+        }
+        else {
+            frame.push(false);
+        }
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execKeys(Context ctx, Instruction instr, CodeFrame frame) {
+        var val = frame.pop();
+
+        var members = Values.getMembers(ctx, val, false, false);
+        Collections.reverse(members);
+
+        frame.push(null);
+
+        for (var el : members) {
+            if (el instanceof Symbol) continue;
+            var obj = new ObjectValue();
+            obj.defineProperty(ctx, "value", el);
+            frame.push(obj);
+        }
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+
+    public static Object execTryStart(Context ctx, Instruction instr, CodeFrame frame) {
+        int start = frame.codePtr + 1;
+        int catchStart = (int)instr.get(0);
+        int finallyStart = (int)instr.get(1);
+        if (finallyStart >= 0) finallyStart += start;
+        if (catchStart >= 0) catchStart += start;
+        int end = (int)instr.get(2) + start;
+        frame.addTry(start, end, catchStart, finallyStart);
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execTryEnd(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.popTryFlag = true;
+        return Values.NO_RETURN;
+    }
+
+    public static Object execDup(Context ctx, Instruction instr, CodeFrame frame) {
+        int count = instr.get(0);
+
+        for (var i = 0; i < count; i++) {
+            frame.push(frame.peek(count - 1));
+        }
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadUndefined(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.push(null);
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadValue(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.push(instr.get(0));
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadVar(Context ctx, Instruction instr, CodeFrame frame) {
+        var i = instr.get(0);
+
+        if (i instanceof String) frame.push(ctx.environment.global.get(ctx, (String)i));
+        else frame.push(frame.scope.get((int)i).get(ctx));
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadObj(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.push(new ObjectValue());
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadGlob(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.push(ctx.environment.global.obj);
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadArr(Context ctx, Instruction instr, CodeFrame frame) {
+        var res = new ArrayValue();
+        res.setSize(instr.get(0));
+        frame.push(res);
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadFunc(Context ctx, Instruction instr, CodeFrame frame) {
+        long id = (Long)instr.get(0);
+        var captures = new ValueVariable[instr.params.length - 1];
+
+        for (var i = 1; i < instr.params.length; i++) {
+            captures[i - 1] = frame.scope.get(instr.get(i));
+        }
+
+        var func = new CodeFunction(ctx.environment, "", Engine.functions.get(id), captures);
+
+        frame.push(func);
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadMember(Context ctx, Instruction instr, CodeFrame frame) {
+        var key = frame.pop();
+        var obj = frame.pop();
+
+        try {
+            frame.push(Values.getMember(ctx, obj, key));
+        }
+        catch (IllegalArgumentException e) {
+            throw EngineException.ofType(e.getMessage());
+        }
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execLoadKeyMember(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.push(instr.get(0));
+        return execLoadMember(ctx, instr, frame);
+    }
+    public static Object execLoadRegEx(Context ctx, Instruction instr, CodeFrame frame) {
+        if (ctx.hasNotNull(Environment.REGEX_CONSTR)) {
+            frame.push(Values.callNew(ctx, ctx.get(Environment.REGEX_CONSTR), instr.get(0), instr.get(1)));
+        }
+        else {
+            throw EngineException.ofSyntax("Regex is not supported.");
+        }
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+
+    public static Object execDiscard(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.pop();
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execStoreMember(Context ctx, Instruction instr, CodeFrame frame) {
+        var val = frame.pop();
+        var key = frame.pop();
+        var obj = frame.pop();
+
+        if (!Values.setMember(ctx, obj, key, val)) throw EngineException.ofSyntax("Can't set member '" + key + "'.");
+        if ((boolean)instr.get(0)) frame.push(val);
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execStoreVar(Context ctx, Instruction instr, CodeFrame frame) {
+        var val = (boolean)instr.get(1) ? frame.peek() : frame.pop();
+        var i = instr.get(0);
+
+        if (i instanceof String) ctx.environment.global.set(ctx, (String)i, val);
+        else frame.scope.get((int)i).set(ctx, val);
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execStoreSelfFunc(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.scope.locals[(int)instr.get(0)].set(ctx, frame.function);
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    
+    public static Object execJmp(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.codePtr += (int)instr.get(0);
+        frame.jumpFlag = true;
+        return Values.NO_RETURN;
+    }
+    public static Object execJmpIf(Context ctx, Instruction instr, CodeFrame frame) {
+        if (Values.toBoolean(frame.pop())) {
+            frame.codePtr += (int)instr.get(0);
+            frame.jumpFlag = true;
+        }
+        else frame.codePtr ++;
+        return Values.NO_RETURN;
+    }
+    public static Object execJmpIfNot(Context ctx, Instruction instr, CodeFrame frame) {
+        if (Values.not(frame.pop())) {
+            frame.codePtr += (int)instr.get(0);
+            frame.jumpFlag = true;
+        }
+        else frame.codePtr ++;
+        return Values.NO_RETURN;
+    }
+
+    public static Object execIn(Context ctx, Instruction instr, CodeFrame frame) {
+        var obj = frame.pop();
+        var index = frame.pop();
+
+        frame.push(Values.hasMember(ctx, obj, index, false));
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execTypeof(Context ctx, Instruction instr, CodeFrame frame) {
+        String name = instr.get(0);
+        Object obj;
+
+        if (name != null) {
+            if (ctx.environment.global.has(ctx, name)) {
+                obj = ctx.environment.global.get(ctx, name);
+            }
+            else obj = null;
+        }
+        else obj = frame.pop();
+
+        frame.push(Values.type(obj));
+
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+    public static Object execNop(Context ctx, Instruction instr, CodeFrame frame) {
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+
+    public static Object execDelete(Context ctx, Instruction instr, CodeFrame frame) {
+        var key = frame.pop();
+        var val = frame.pop();
+
+        if (!Values.deleteMember(ctx, val, key)) throw EngineException.ofSyntax("Can't delete member '" + key + "'.");
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+
+    public static Object execOperation(Context ctx, Instruction instr, CodeFrame frame) {
+        Operation op = instr.get(0);
+        var args = new Object[op.operands];
+
+        for (var i = op.operands - 1; i >= 0; i--) args[i] = frame.pop();
+
+        frame.push(Values.operation(ctx, op, args));
+        frame.codePtr++;
+        return Values.NO_RETURN;
+    }
+
+    public static Object exec(Context ctx, Instruction instr, CodeFrame frame) {
+        switch (instr.type) {
+            case NOP: return execNop(ctx, instr, frame);
+            case RETURN: return execReturn(ctx, instr, frame);
+            case THROW: return execThrow(ctx, instr, frame);
+            case THROW_SYNTAX: return execThrowSyntax(ctx, instr, frame);
+            case CALL: return execCall(ctx, instr, frame);
+            case CALL_NEW: return execCallNew(ctx, instr, frame);
+            case TRY_START: return execTryStart(ctx, instr, frame);
+            case TRY_END: return execTryEnd(ctx, instr, frame);
+
+            case DUP: return execDup(ctx, instr, frame);
+            case LOAD_VALUE: return execLoadValue(ctx, instr, frame);
+            case LOAD_VAR: return execLoadVar(ctx, instr, frame);
+            case LOAD_OBJ: return execLoadObj(ctx, instr, frame);
+            case LOAD_ARR: return execLoadArr(ctx, instr, frame);
+            case LOAD_FUNC: return execLoadFunc(ctx, instr, frame);
+            case LOAD_MEMBER: return execLoadMember(ctx, instr, frame);
+            case LOAD_VAL_MEMBER: return execLoadKeyMember(ctx, instr, frame);
+            case LOAD_REGEX: return execLoadRegEx(ctx, instr, frame);
+            case LOAD_GLOB: return execLoadGlob(ctx, instr, frame);
+
+            case DISCARD: return execDiscard(ctx, instr, frame);
+            case STORE_MEMBER: return execStoreMember(ctx, instr, frame);
+            case STORE_VAR: return execStoreVar(ctx, instr, frame);
+            case STORE_SELF_FUNC: return execStoreSelfFunc(ctx, instr, frame);
+            case MAKE_VAR: return execMakeVar(ctx, instr, frame);
+
+            case KEYS: return execKeys(ctx, instr, frame);
+            case DEF_PROP: return execDefProp(ctx, instr, frame);
+            case TYPEOF: return execTypeof(ctx, instr, frame);
+            case DELETE: return execDelete(ctx, instr, frame);
+
+            case JMP: return execJmp(ctx, instr, frame);
+            case JMP_IF: return execJmpIf(ctx, instr, frame);
+            case JMP_IFN: return execJmpIfNot(ctx, instr, frame);
+
+            case OPERATION: return execOperation(ctx, instr, frame);
+
+            default: throw EngineException.ofSyntax("Invalid instruction " + instr.type.name() + ".");
+        }
+    }
+}

src/me/topchetoeu/jscript/engine/scope/GlobalScope.java

@@ -1,81 +1,78 @@
-package me.topchetoeu.jscript.engine.scope;
-
-import java.util.HashSet;
-import java.util.Set;
-
-import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.values.FunctionValue;
-import me.topchetoeu.jscript.engine.values.NativeFunction;
-import me.topchetoeu.jscript.engine.values.ObjectValue;
-import me.topchetoeu.jscript.exceptions.EngineException;
-
-public class GlobalScope implements ScopeRecord {
-    public final ObjectValue obj;
-
-    @Override
-    public GlobalScope parent() { return null; }
-
-    public boolean has(Context ctx, String name) {
-        return obj.hasMember(ctx, name, false);
-    }
-    public Object getKey(String name) {
-        return name;
-    }
-
-    public GlobalScope globalChild() {
-        var obj = new ObjectValue();
-        obj.setPrototype(null, this.obj);
-        return new GlobalScope(obj);
-    }
-    public LocalScopeRecord child() {
-        return new LocalScopeRecord(this);
-    }
-
-    public Object define(String name) {
-        if (obj.hasMember(null, name, true)) return name;
-        obj.defineProperty(null, name, null);
-        return name;
-    }
-    public void define(String name, Variable val) {
-        obj.defineProperty(null, name,
-            new NativeFunction("get " + name, (ctx, th, a) -> val.get(ctx)),
-            new NativeFunction("set " + name, (ctx, th, args) -> { val.set(ctx, args.length > 0 ? args[0] : null); return null; }),
-            true, true
-        );
-    }
-    public void define(Context ctx, String name, boolean readonly, Object val) {
-        obj.defineProperty(ctx, name, val, readonly, true, true);
-    }
-    public void define(String ...names) {
-        for (var n : names) define(n);
-    }
-    public void define(boolean readonly, FunctionValue val) {
-        define(null, val.name, readonly, val);
-    }
-
-    public Object get(Context ctx, String name) {
-        if (!obj.hasMember(ctx, name, false)) throw EngineException.ofSyntax("The variable '" + name + "' doesn't exist.");
-        else return obj.getMember(ctx, name);
-    }
-    public void set(Context ctx, String name, Object val) {
-        if (!obj.hasMember(ctx, name, false)) throw EngineException.ofSyntax("The variable '" + name + "' doesn't exist.");
-        if (!obj.setMember(ctx, name, val, false)) throw EngineException.ofSyntax("The global '" + name + "' is readonly.");
-    }
-
-    public Set<String> keys() {
-        var res = new HashSet<String>();
-
-        for (var key : keys()) {
-            if (key instanceof String) res.add((String)key);
-        }
-
-        return res;
-    }
-
-    public GlobalScope() {
-        this.obj = new ObjectValue();
-    }
-    public GlobalScope(ObjectValue val) {
-        this.obj = val;
-    }
-}
+package me.topchetoeu.jscript.engine.scope;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.values.FunctionValue;
+import me.topchetoeu.jscript.engine.values.NativeFunction;
+import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.exceptions.EngineException;
+
+public class GlobalScope implements ScopeRecord {
+    public final ObjectValue obj;
+
+    public boolean has(Context ctx, String name) {
+        return obj.hasMember(ctx, name, false);
+    }
+    public Object getKey(String name) {
+        return name;
+    }
+
+    public GlobalScope globalChild() {
+        var obj = new ObjectValue();
+        obj.setPrototype(null, this.obj);
+        return new GlobalScope(obj);
+    }
+    public LocalScopeRecord child() {
+        return new LocalScopeRecord();
+    }
+
+    public Object define(String name) {
+        if (obj.hasMember(null, name, true)) return name;
+        obj.defineProperty(null, name, null);
+        return name;
+    }
+    public void define(String name, Variable val) {
+        obj.defineProperty(null, name,
+            new NativeFunction("get " + name, args -> val.get(args.ctx)),
+            new NativeFunction("set " + name, args -> { val.set(args.ctx, args.get(0)); return null; }),
+            true, true
+        );
+    }
+    public void define(Context ctx, String name, boolean readonly, Object val) {
+        obj.defineProperty(ctx, name, val, readonly, true, true);
+    }
+    public void define(String ...names) {
+        for (var n : names) define(n);
+    }
+    public void define(boolean readonly, FunctionValue val) {
+        define(null, val.name, readonly, val);
+    }
+
+    public Object get(Context ctx, String name) {
+        if (!obj.hasMember(ctx, name, false)) throw EngineException.ofSyntax("The variable '" + name + "' doesn't exist.");
+        else return obj.getMember(ctx, name);
+    }
+    public void set(Context ctx, String name, Object val) {
+        if (!obj.hasMember(ctx, name, false)) throw EngineException.ofSyntax("The variable '" + name + "' doesn't exist.");
+        if (!obj.setMember(ctx, name, val, false)) throw EngineException.ofSyntax("The global '" + name + "' is readonly.");
+    }
+
+    public Set<String> keys() {
+        var res = new HashSet<String>();
+
+        for (var key : keys()) {
+            if (key instanceof String) res.add((String)key);
+        }
+
+        return res;
+    }
+
+    public GlobalScope() {
+        this.obj = new ObjectValue();
+    }
+    public GlobalScope(ObjectValue val) {
+        this.obj = val;
+    }
+}

src/me/topchetoeu/jscript/engine/scope/LocalScope.java

@@ -1,30 +1,29 @@
-package me.topchetoeu.jscript.engine.scope;
-
-import java.util.ArrayList;
-
-public class LocalScope {
-    public final ValueVariable[] captures;
-    public final ValueVariable[] locals;
-    public final ArrayList<ValueVariable> catchVars = new ArrayList<>();
-
-    public ValueVariable get(int i) {
-        if (i >= locals.length)
-            return catchVars.get(i - locals.length);
-        if (i >= 0) return locals[i];
-        else return captures[~i];
-    }
-
-
-    public int size() {
-        return captures.length + locals.length;
-    }
-
-    public LocalScope(int n, ValueVariable[] captures) {
-        locals = new ValueVariable[n];
-        this.captures = captures;
-
-        for (int i = 0; i < n; i++) {
-            locals[i] = new ValueVariable(false, null);
-        }
-    }
-}
+package me.topchetoeu.jscript.engine.scope;
+
+import java.util.ArrayList;
+
+public class LocalScope {
+    public final ValueVariable[] captures;
+    public final ValueVariable[] locals;
+    public final ArrayList<ValueVariable> catchVars = new ArrayList<>();
+
+    public ValueVariable get(int i) {
+        if (i >= locals.length) return catchVars.get(i - locals.length);
+        if (i >= 0) return locals[i];
+        else return captures[~i];
+    }
+
+
+    public int size() {
+        return captures.length + locals.length;
+    }
+
+    public LocalScope(int n, ValueVariable[] captures) {
+        locals = new ValueVariable[n];
+        this.captures = captures;
+
+        for (int i = 0; i < n; i++) {
+            locals[i] = new ValueVariable(false, null);
+        }
+    }
+}

src/me/topchetoeu/jscript/engine/scope/LocalScopeRecord.java

@@ -1,91 +1,77 @@
-package me.topchetoeu.jscript.engine.scope;
-
-import java.util.ArrayList;
-
-import me.topchetoeu.jscript.engine.Context;
-
-public class LocalScopeRecord implements ScopeRecord {
-    public final LocalScopeRecord parent;
-    public final GlobalScope global;
-
-    private final ArrayList<String> captures = new ArrayList<>();
-    private final ArrayList<String> locals = new ArrayList<>();
-
-    public String[] captures() {
-        return captures.toArray(String[]::new);
-    }
-    public String[] locals() {
-        return locals.toArray(String[]::new);
-    }
-
-    @Override
-    public LocalScopeRecord parent() { return parent; }
-
-    public LocalScopeRecord child() {
-        return new LocalScopeRecord(this, global);
-    }
-
-    public int localsCount() {
-        return locals.size();
-    }
-    public int capturesCount() {
-        return captures.size();
-    }
-
-    public int[] getCaptures() {
-        var buff = new int[captures.size()];
-        var i = 0;
-
-        for (var name : captures) {
-            var index = parent.getKey(name);
-            if (index instanceof Integer) buff[i++] = (int)index;
-        }
-
-        var res = new int[i];
-        System.arraycopy(buff, 0, res, 0, i);
-
-        return res;
-    }
-
-    public Object getKey(String name) {
-        var capI = captures.indexOf(name);
-        var locI = locals.lastIndexOf(name);
-        if (locI >= 0) return locI;
-        if (capI >= 0) return ~capI;
-        if (parent != null) {
-            var res = parent.getKey(name);
-            if (res != null && res instanceof Integer) {
-                captures.add(name);
-                return -captures.size();
-            }
-        }
-
-        return name;
-    }
-    public boolean has(Context ctx, String name) {
-        return
-            global.has(ctx, name) ||
-            locals.contains(name) ||
-            parent != null && parent.has(ctx, name);
-    }
-    public Object define(String name, boolean force) {
-        if (!force && locals.contains(name)) return locals.indexOf(name);
-        locals.add(name);
-        return locals.size() - 1;
-    }
-    public Object define(String name) {
-        return define(name, false);
-    }
-    public void undefine() {
-        locals.remove(locals.size() - 1);
-    }
-
-    public LocalScopeRecord(GlobalScope global) {
-        this.parent = null;
-        this.global = global;
-    }
-    public LocalScopeRecord(LocalScopeRecord parent, GlobalScope global) {
-        this.parent = parent;
-        this.global = global;
-    }
-}
+package me.topchetoeu.jscript.engine.scope;
+
+import java.util.ArrayList;
+
+public class LocalScopeRecord implements ScopeRecord {
+    public final LocalScopeRecord parent;
+
+    private final ArrayList<String> captures = new ArrayList<>();
+    private final ArrayList<String> locals = new ArrayList<>();
+
+    public String[] captures() {
+        return captures.toArray(String[]::new);
+    }
+    public String[] locals() {
+        return locals.toArray(String[]::new);
+    }
+
+    public LocalScopeRecord child() {
+        return new LocalScopeRecord(this);
+    }
+
+    public int localsCount() {
+        return locals.size();
+    }
+    public int capturesCount() {
+        return captures.size();
+    }
+
+    public int[] getCaptures() {
+        var buff = new int[captures.size()];
+        var i = 0;
+
+        for (var name : captures) {
+            var index = parent.getKey(name);
+            if (index instanceof Integer) buff[i++] = (int)index;
+        }
+
+        var res = new int[i];
+        System.arraycopy(buff, 0, res, 0, i);
+
+        return res;
+    }
+
+    public Object getKey(String name) {
+        var capI = captures.indexOf(name);
+        var locI = locals.lastIndexOf(name);
+        if (locI >= 0) return locI;
+        if (capI >= 0) return ~capI;
+        if (parent != null) {
+            var res = parent.getKey(name);
+            if (res != null && res instanceof Integer) {
+                captures.add(name);
+                return -captures.size();
+            }
+        }
+
+        return name;
+    }
+    public Object define(String name, boolean force) {
+        if (!force && locals.contains(name)) return locals.indexOf(name);
+        locals.add(name);
+        return locals.size() - 1;
+    }
+    public Object define(String name) {
+        return define(name, false);
+    }
+    public void undefine() {
+        locals.remove(locals.size() - 1);
+    }
+
+    public LocalScopeRecord() {
+        this.parent = null;
+    }
+    public LocalScopeRecord(LocalScopeRecord parent) {
+        this.parent = parent;
+    }
+}

src/me/topchetoeu/jscript/engine/scope/ScopeRecord.java

@@ -1,8 +1,7 @@
-package me.topchetoeu.jscript.engine.scope;
-
-public interface ScopeRecord {
-    public Object getKey(String name);
-    public Object define(String name);
-    public ScopeRecord parent();
-    public LocalScopeRecord child();
-}
+package me.topchetoeu.jscript.engine.scope;
+
+public interface ScopeRecord {
+    public Object getKey(String name);
+    public Object define(String name);
+    public LocalScopeRecord child();
+}

src/me/topchetoeu/jscript/engine/scope/ValueVariable.java

@@ -1,28 +1,28 @@
-package me.topchetoeu.jscript.engine.scope;
-
-import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.values.Values;
-
-public class ValueVariable implements Variable {
-    public boolean readonly;
-    public Object value;
-
-    @Override
-    public boolean readonly() { return readonly; }
-
-    @Override
-    public Object get(Context ctx) {
-        return value;
-    }
-
-    @Override
-    public void set(Context ctx, Object val) {
-        if (readonly) return;
-        this.value = Values.normalize(ctx, val);
-    }
-    
-    public ValueVariable(boolean readonly, Object val) {
-        this.readonly = readonly;
-        this.value = val;
-    }
-}
+package me.topchetoeu.jscript.engine.scope;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.values.Values;
+
+public class ValueVariable implements Variable {
+    public boolean readonly;
+    public Object value;
+
+    @Override
+    public boolean readonly() { return readonly; }
+
+    @Override
+    public Object get(Context ctx) {
+        return value;
+    }
+
+    @Override
+    public void set(Context ctx, Object val) {
+        if (readonly) return;
+        this.value = Values.normalize(ctx, val);
+    }
+    
+    public ValueVariable(boolean readonly, Object val) {
+        this.readonly = readonly;
+        this.value = val;
+    }
+}

src/me/topchetoeu/jscript/engine/scope/Variable.java

@@ -1,9 +1,9 @@
-package me.topchetoeu.jscript.engine.scope;
-
-import me.topchetoeu.jscript.engine.Context;
-
-public interface Variable {
-    Object get(Context ctx);
-    default boolean readonly() { return true; }
-    default void set(Context ctx, Object val) { }
-}
+package me.topchetoeu.jscript.engine.scope;
+
+import me.topchetoeu.jscript.engine.Context;
+
+public interface Variable {
+    Object get(Context ctx);
+    default boolean readonly() { return true; }
+    default void set(Context ctx, Object val) { }
+}

src/me/topchetoeu/jscript/engine/values/ArrayValue.java

@@ -1,218 +1,222 @@
-package me.topchetoeu.jscript.engine.values;
-
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Comparator;
-import java.util.Iterator;
-import java.util.List;
-
-import me.topchetoeu.jscript.engine.Context;
-
-// TODO: Make methods generic
-public class ArrayValue extends ObjectValue implements Iterable<Object> {
-    private static final Object UNDEFINED = new Object();
-    private Object[] values;
-    private int size;
-
-    private void alloc(int index) {
-        if (index < values.length) return;
-        if (index < values.length * 2) index = values.length * 2;
-
-        var arr = new Object[index];
-        System.arraycopy(values, 0, arr, 0, values.length);
-        values = arr;
-    }
-
-    public int size() { return size; }
-    public boolean setSize(int val) {
-        if (val < 0) return false;
-        if (size > val) shrink(size - val);
-        else {
-            alloc(val);
-            size = val;
-        }
-        return true;
-    }
-
-    public Object get(int i) {
-        if (i < 0 || i >= size) return null;
-        var res = values[i];
-        if (res == UNDEFINED) return null;
-        else return res;
-    }
-    public void set(Context ctx, int i, Object val) {
-        if (i < 0) return;
-
-        alloc(i);
-
-        val = Values.normalize(ctx, val);
-        if (val == null) val = UNDEFINED;
-        values[i] = val;
-        if (i >= size) size = i + 1;
-    }
-    public boolean has(int i) {
-        return i >= 0 && i < values.length && values[i] != null;
-    }
-    public void remove(int i) {
-        if (i < 0 || i >= values.length) return;
-        values[i] = null;
-    }
-    public void shrink(int n) {
-        if (n >= values.length) {
-            values = new Object[16];
-            size = 0;
-        }
-        else {
-            for (int i = 0; i < n; i++) {
-                values[--size] = null;
-            }
-        }
-    }
-
-    public Object[] toArray() {
-        Object[] res = new Object[size];
-        copyTo(res, 0, 0, size);
-        return res;
-    }
-    public void copyTo(Object[] arr, int sourceStart, int destStart, int count) {
-        for (var i = 0; i < count; i++) {
-            if (i + sourceStart < 0 || i + sourceStart >= size) arr[i + destStart] = null;
-            if (values[i + sourceStart] == UNDEFINED) arr[i + destStart] = null;
-            else arr[i + sourceStart] = values[i + destStart];
-        }
-    }
-    public void copyTo(Context ctx, ArrayValue arr, int sourceStart, int destStart, int count) {
-        // Iterate in reverse to reallocate at most once
-        for (var i = count - 1; i >= 0; i--) {
-            if (i + sourceStart < 0 || i + sourceStart >= size) arr.set(ctx, i + destStart, null);
-            if (values[i + sourceStart] == UNDEFINED) arr.set(ctx, i + destStart, null);
-            else arr.set(ctx, i + destStart, values[i + sourceStart]);
-        }
-    }
-
-    public void copyFrom(Context ctx, Object[] arr, int sourceStart, int destStart, int count) {
-        for (var i = 0; i < count; i++) {
-            set(ctx, i + destStart, arr[i + sourceStart]);
-        }
-    }
-
-    public void move(int srcI, int dstI, int n) {
-        alloc(dstI + n);
-
-        System.arraycopy(values, srcI, values, dstI, n);
-
-        if (dstI + n >= size) size = dstI + n;
-    }
-
-    public void sort(Comparator<Object> comparator) {
-        Arrays.sort(values, 0, size, (a, b) -> {
-            var _a = 0;
-            var _b = 0;
-
-            if (a == UNDEFINED) _a = 1;
-            if (a == null) _a = 2;
-
-            if (b == UNDEFINED) _b = 1;
-            if (b == null) _b = 2;
-
-            if (_a != 0 || _b != 0) return Integer.compare(_a, _b);
-
-            return comparator.compare(a, b);
-        });
-    }
-
-    @Override
-    protected Object getField(Context ctx, Object key) {
-        if (key instanceof Number) {
-            var i = ((Number)key).doubleValue();
-            if (i >= 0 && i - Math.floor(i) == 0) {
-                return get((int)i);
-            }
-        }
-
-        return super.getField(ctx, key);
-    }
-    @Override
-    protected boolean setField(Context ctx, Object key, Object val) {
-        if (key instanceof Number) {
-            var i = Values.number(key);
-            if (i >= 0 && i - Math.floor(i) == 0) {
-                set(ctx, (int)i, val);
-                return true;
-            }
-        }
-
-        return super.setField(ctx, key, val);
-    }
-    @Override
-    protected boolean hasField(Context ctx, Object key) {
-        if (key instanceof Number) {
-            var i = Values.number(key);
-            if (i >= 0 && i - Math.floor(i) == 0) {
-                return has((int)i);
-            }
-        }
-
-        return super.hasField(ctx, key);
-    }
-    @Override
-    protected void deleteField(Context ctx, Object key) {
-        if (key instanceof Number) {
-            var i = Values.number(key);
-            if (i >= 0 && i - Math.floor(i) == 0) {
-                remove((int)i);
-                return;
-            }
-        }
-
-        super.deleteField(ctx, key);
-    }
-
-    @Override
-    public List<Object> keys(boolean includeNonEnumerable) {
-        var res = super.keys(includeNonEnumerable);
-        for (var i = 0; i < size(); i++) {
-            if (has(i)) res.add(i);
-        }
-        return res;
-    }
-
-    @Override
-    public Iterator<Object> iterator() {
-        return new Iterator<Object>() {
-            private int i = 0;
-
-            @Override
-            public boolean hasNext() {
-                return i < size();
-            }
-            @Override
-            public Object next() {
-                if (!hasNext()) return null;
-                return get(i++);
-            }
-        };
-    }
-
-    public ArrayValue() {
-        super(PlaceholderProto.ARRAY);
-        values = new Object[16];
-        size = 0;
-    }
-    public ArrayValue(int cap) {
-        super(PlaceholderProto.ARRAY);
-        values = new Object[cap];
-        size = 0;
-    }
-    public ArrayValue(Context ctx, Object ...values) {
-        this();
-        this.values = new Object[values.length];
-        size = values.length;
-
-        for (var i = 0; i < size; i++) this.values[i] = Values.normalize(ctx, values[i]);
-    }
-
-    public static ArrayValue of(Context ctx, Collection<?> values) {
-        return new ArrayValue(ctx, values.toArray(Object[]::new));
-    }
-}
+package me.topchetoeu.jscript.engine.values;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.List;
+
+import me.topchetoeu.jscript.engine.Context;
+
+// TODO: Make methods generic
+public class ArrayValue extends ObjectValue implements Iterable<Object> {
+    private static final Object UNDEFINED = new Object();
+    private Object[] values;
+    private int size;
+
+    private Object[] alloc(int index) {
+        index++;
+        if (index < values.length) return values;
+        if (index < values.length * 2) index = values.length * 2;
+
+        var arr = new Object[index];
+        System.arraycopy(values, 0, arr, 0, values.length);
+        return arr;
+    }
+
+    public int size() { return size; }
+    public boolean setSize(int val) {
+        if (val < 0) return false;
+        if (size > val) shrink(size - val);
+        else {
+            values = alloc(val);
+            size = val;
+        }
+        return true;
+    }
+
+    public Object get(int i) {
+        if (i < 0 || i >= size) return null;
+        var res = values[i];
+        if (res == UNDEFINED) return null;
+        else return res;
+    }
+    public void set(Context ctx, int i, Object val) {
+        if (i < 0) return;
+
+        values = alloc(i);
+
+        val = Values.normalize(ctx, val);
+        if (val == null) val = UNDEFINED;
+        values[i] = val;
+        if (i >= size) size = i + 1;
+    }
+    public boolean has(int i) {
+        return i >= 0 && i < size && values[i] != null;
+    }
+    public void remove(int i) {
+        if (i < 0 || i >= values.length) return;
+        values[i] = null;
+    }
+    public void shrink(int n) {
+        if (n >= values.length) {
+            values = new Object[16];
+            size = 0;
+        }
+        else {
+            for (int i = 0; i < n; i++) {
+                values[--size] = null;
+            }
+        }
+    }
+
+    public Object[] toArray() {
+        Object[] res = new Object[size];
+        copyTo(res, 0, 0, size);
+        return res;
+    }
+    public void copyTo(Object[] arr, int sourceStart, int destStart, int count) {
+        for (var i = 0; i < count; i++) {
+            if (i + sourceStart < 0 || i + sourceStart >= size) arr[i + destStart] = null;
+            if (values[i + sourceStart] == UNDEFINED) arr[i + destStart] = null;
+            else arr[i + sourceStart] = values[i + destStart];
+        }
+    }
+    public void copyTo(Context ctx, ArrayValue arr, int sourceStart, int destStart, int count) {
+        // Iterate in reverse to reallocate at most once
+        if (destStart + count > arr.size) arr.size = destStart + count;
+
+        for (var i = count - 1; i >= 0; i--) {
+            if (i + sourceStart < 0 || i + sourceStart >= size) arr.remove(i + destStart);
+            if (values[i + sourceStart] == UNDEFINED) arr.set(ctx, i + destStart, null);
+            else if (values[i + sourceStart] == null) arr.remove(i + destStart);
+            else arr.set(ctx, i + destStart, values[i + sourceStart]);
+        }
+    }
+
+    public void copyFrom(Context ctx, Object[] arr, int sourceStart, int destStart, int count) {
+        for (var i = 0; i < count; i++) {
+            set(ctx, i + destStart, arr[i + sourceStart]);
+        }
+    }
+
+    public void move(int srcI, int dstI, int n) {
+        values = alloc(dstI + n);
+
+        System.arraycopy(values, srcI, values, dstI, n);
+
+        if (dstI + n >= size) size = dstI + n;
+    }
+
+    public void sort(Comparator<Object> comparator) {
+        Arrays.sort(values, 0, size, (a, b) -> {
+            var _a = 0;
+            var _b = 0;
+
+            if (a == UNDEFINED) _a = 1;
+            if (a == null) _a = 2;
+
+            if (b == UNDEFINED) _b = 1;
+            if (b == null) _b = 2;
+
+            if (_a != 0 || _b != 0) return Integer.compare(_a, _b);
+
+            return comparator.compare(a, b);
+        });
+    }
+
+    @Override
+    protected Object getField(Context ctx, Object key) {
+        if (key instanceof Number) {
+            var i = ((Number)key).doubleValue();
+            if (i >= 0 && i - Math.floor(i) == 0) {
+                return get((int)i);
+            }
+        }
+
+        return super.getField(ctx, key);
+    }
+    @Override
+    protected boolean setField(Context ctx, Object key, Object val) {
+        if (key instanceof Number) {
+            var i = Values.number(key);
+            if (i >= 0 && i - Math.floor(i) == 0) {
+                set(ctx, (int)i, val);
+                return true;
+            }
+        }
+
+        return super.setField(ctx, key, val);
+    }
+    @Override
+    protected boolean hasField(Context ctx, Object key) {
+        if (key instanceof Number) {
+            var i = Values.number(key);
+            if (i >= 0 && i - Math.floor(i) == 0) {
+                return has((int)i);
+            }
+        }
+
+        return super.hasField(ctx, key);
+    }
+    @Override
+    protected void deleteField(Context ctx, Object key) {
+        if (key instanceof Number) {
+            var i = Values.number(key);
+            if (i >= 0 && i - Math.floor(i) == 0) {
+                remove((int)i);
+                return;
+            }
+        }
+
+        super.deleteField(ctx, key);
+    }
+
+    @Override
+    public List<Object> keys(boolean includeNonEnumerable) {
+        var res = super.keys(includeNonEnumerable);
+        for (var i = 0; i < size(); i++) {
+            if (has(i)) res.add(i);
+        }
+        return res;
+    }
+
+    @Override
+    public Iterator<Object> iterator() {
+        return new Iterator<Object>() {
+            private int i = 0;
+
+            @Override
+            public boolean hasNext() {
+                return i < size();
+            }
+            @Override
+            public Object next() {
+                if (!hasNext()) return null;
+                return get(i++);
+            }
+        };
+    }
+
+    public ArrayValue() {
+        super(PlaceholderProto.ARRAY);
+        values = new Object[16];
+        size = 0;
+    }
+    public ArrayValue(int cap) {
+        super(PlaceholderProto.ARRAY);
+        values = new Object[cap];
+        size = 0;
+    }
+    public ArrayValue(Context ctx, Object ...values) {
+        this();
+        this.values = new Object[values.length];
+        size = values.length;
+
+        for (var i = 0; i < size; i++) this.values[i] = Values.normalize(ctx, values[i]);
+    }
+
+    public static ArrayValue of(Context ctx, Collection<?> values) {
+        return new ArrayValue(ctx, values.toArray(Object[]::new));
+    }
+}

src/me/topchetoeu/jscript/engine/values/CodeFunction.java

@@ -1,60 +1,57 @@
-package me.topchetoeu.jscript.engine.values;
-
-import me.topchetoeu.jscript.Location;
-import me.topchetoeu.jscript.compilation.FunctionBody;
-import me.topchetoeu.jscript.compilation.Instruction;
-import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Environment;
-import me.topchetoeu.jscript.engine.StackData;
-import me.topchetoeu.jscript.engine.frame.CodeFrame;
-import me.topchetoeu.jscript.engine.frame.Runners;
-import me.topchetoeu.jscript.engine.scope.ValueVariable;
-
-public class CodeFunction extends FunctionValue {
-    public final int localsN;
-    public final int length;
-    public final Instruction[] body;
-    public final String[] captureNames, localNames;
-    public final ValueVariable[] captures;
-    public Environment environment;
-
-    public Location loc() {
-        for (var instr : body) {
-            if (instr.location != null) return instr.location;
-        }
-        return null;
-    }
-    public String readable() {
-        var loc = loc();
-        if (loc == null) return name;
-        else if (name.equals("")) return loc.toString();
-        else return name + "@" + loc;
-    }
-
-    @Override
-    public Object call(Context ctx, Object thisArg, Object ...args) {
-        var frame = new CodeFrame(ctx, thisArg, args, this);
-        try {
-            StackData.pushFrame(ctx, frame);
-
-            while (true) {
-                var res = frame.next(ctx, Runners.NO_RETURN, Runners.NO_RETURN, null);
-                if (res != Runners.NO_RETURN) return res;
-            }
-        }
-        finally {
-            StackData.popFrame(ctx, frame);
-        }
-    }
-
-    public CodeFunction(Environment environment, String name, int localsN, int length, ValueVariable[] captures, FunctionBody body) {
-        super(name, length);
-        this.captures = captures;
-        this.captureNames = body.captureNames;
-        this.localNames = body.localNames;
-        this.environment = environment;
-        this.localsN = localsN;
-        this.length = length;
-        this.body = body.instructions;
-    }
-}
+package me.topchetoeu.jscript.engine.values;
+
+import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.compilation.FunctionBody;
+import me.topchetoeu.jscript.compilation.Instruction;
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.Environment;
+import me.topchetoeu.jscript.engine.frame.CodeFrame;
+import me.topchetoeu.jscript.engine.scope.ValueVariable;
+
+public class CodeFunction extends FunctionValue {
+    public final int localsN;
+    public final Instruction[] body;
+    public final String[] captureNames, localNames;
+    public final ValueVariable[] captures;
+    public Environment environment;
+
+    public Location loc() {
+        for (var instr : body) {
+            if (instr.location != null) return instr.location;
+        }
+        return null;
+    }
+    public String readable() {
+        var loc = loc();
+        if (loc == null) return name;
+        else if (name.equals("")) return loc.toString();
+        else return name + "@" + loc;
+    }
+
+    @Override
+    public Object call(Context ctx, Object thisArg, Object ...args) {
+        var frame = new CodeFrame(ctx, thisArg, args, this);
+
+        frame.onPush();
+
+        try {
+            while (true) {
+                var res = frame.next(Values.NO_RETURN, Values.NO_RETURN, null);
+                if (res != Values.NO_RETURN) return res;
+            }
+        }
+        finally {
+            frame.onPop();
+        }
+    }
+
+    public CodeFunction(Environment environment, String name, FunctionBody body, ValueVariable... captures) {
+        super(name, body.argsN);
+        this.captures = captures;
+        this.captureNames = body.captureNames;
+        this.localNames = body.localNames;
+        this.environment = environment;
+        this.localsN = body.localsN;
+        this.body = body.instructions;
+    }
+}

src/me/topchetoeu/jscript/engine/values/FunctionValue.java

@@ -1,70 +1,70 @@
-package me.topchetoeu.jscript.engine.values;
-
-import java.util.List;
-
-import me.topchetoeu.jscript.engine.Context;
-
-public abstract class FunctionValue extends ObjectValue {
-    public String name = "";
-    public boolean special = false;
-    public int length;
-
-    @Override
-    public String toString() {
-        return "function(...) {  ...}";
-    }
-
-    public abstract Object call(Context ctx, Object thisArg, Object ...args);
-    public Object call(Context ctx) {
-        return call(ctx, null);
-    }
-
-    @Override
-    protected Object getField(Context ctx, Object key) {
-        if (key.equals("name")) return name;
-        if (key.equals("length")) return length;
-        return super.getField(ctx, key);
-    }
-    @Override
-    protected boolean setField(Context ctx, Object key, Object val) {
-        if (key.equals("name")) name = Values.toString(ctx, val);
-        else if (key.equals("length")) length = (int)Values.toNumber(ctx, val);
-        else return super.setField(ctx, key, val);
-        return true;
-    }
-    @Override
-    protected boolean hasField(Context ctx, Object key) {
-        if (key.equals("name")) return true;
-        if (key.equals("length")) return true;
-        return super.hasField(ctx, key);
-    }
-
-    @Override
-    public List<Object> keys(boolean includeNonEnumerable) {
-        var res = super.keys(includeNonEnumerable);
-        if (includeNonEnumerable) {
-            res.add("name");
-            res.add("length");
-        }
-        return res;
-    }
-
-    public FunctionValue(String name, int length) {
-        super(PlaceholderProto.FUNCTION);
-
-        if (name == null) name = "";
-        this.length = length;
-        this.name = name;
-
-        nonConfigurableSet.add("name");
-        nonEnumerableSet.add("name");
-        nonWritableSet.add("length");
-        nonConfigurableSet.add("length");
-        nonEnumerableSet.add("length");
-
-        var proto = new ObjectValue();
-        proto.defineProperty(null, "constructor", this, true, false, false);
-        this.defineProperty(null, "prototype", proto, true, false, false);
-    }
-}
-
+package me.topchetoeu.jscript.engine.values;
+
+import java.util.List;
+
+import me.topchetoeu.jscript.engine.Context;
+
+public abstract class FunctionValue extends ObjectValue {
+    public String name = "";
+    public boolean special = false;
+    public int length;
+
+    @Override
+    public String toString() {
+        return String.format("function %s(...)", name);
+    }
+
+    public abstract Object call(Context ctx, Object thisArg, Object ...args);
+    public Object call(Context ctx) {
+        return call(ctx, null);
+    }
+
+    @Override
+    protected Object getField(Context ctx, Object key) {
+        if ("name".equals(key)) return name;
+        if ("length".equals(key)) return length;
+        return super.getField(ctx, key);
+    }
+    @Override
+    protected boolean setField(Context ctx, Object key, Object val) {
+        if ("name".equals(key)) name = Values.toString(ctx, val);
+        else if ("length".equals(key)) length = (int)Values.toNumber(ctx, val);
+        else return super.setField(ctx, key, val);
+        return true;
+    }
+    @Override
+    protected boolean hasField(Context ctx, Object key) {
+        if ("name".equals(key)) return true;
+        if ("length".equals(key)) return true;
+        return super.hasField(ctx, key);
+    }
+
+    @Override
+    public List<Object> keys(boolean includeNonEnumerable) {
+        var res = super.keys(includeNonEnumerable);
+        if (includeNonEnumerable) {
+            res.add("name");
+            res.add("length");
+        }
+        return res;
+    }
+
+    public FunctionValue(String name, int length) {
+        super(PlaceholderProto.FUNCTION);
+
+        if (name == null) name = "";
+        this.length = length;
+        this.name = name;
+
+        nonConfigurableSet.add("name");
+        nonEnumerableSet.add("name");
+        nonWritableSet.add("length");
+        nonConfigurableSet.add("length");
+        nonEnumerableSet.add("length");
+
+        var proto = new ObjectValue();
+        proto.defineProperty(null, "constructor", this, true, false, false);
+        this.defineProperty(null, "prototype", proto, true, false, false);
+    }
+}
+

src/me/topchetoeu/jscript/engine/values/NativeFunction.java

@@ -1,25 +1,26 @@
-package me.topchetoeu.jscript.engine.values;
-
-import me.topchetoeu.jscript.engine.Context;
-
-public class NativeFunction extends FunctionValue {
-    public static interface NativeFunctionRunner {
-        Object run(Context ctx, Object thisArg, Object[] args);
-    }
-
-    public final NativeFunctionRunner action;
-
-    @Override
-    public Object call(Context ctx, Object thisArg, Object ...args) {
-        return action.run(ctx, thisArg, args);
-    }
-
-    public NativeFunction(String name, NativeFunctionRunner action) {
-        super(name, 0);
-        this.action = action;
-    }
-    public NativeFunction(NativeFunctionRunner action) {
-        super("", 0);
-        this.action = action;
-    }
-}
+package me.topchetoeu.jscript.engine.values;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.interop.Arguments;
+
+public class NativeFunction extends FunctionValue {
+    public static interface NativeFunctionRunner {
+        Object run(Arguments args);
+    }
+
+    public final NativeFunctionRunner action;
+
+    @Override
+    public Object call(Context ctx, Object thisArg, Object ...args) {
+        return action.run(new Arguments(ctx, thisArg, args));
+    }
+
+    public NativeFunction(String name, NativeFunctionRunner action) {
+        super(name, 0);
+        this.action = action;
+    }
+    public NativeFunction(NativeFunctionRunner action) {
+        super("", 0);
+        this.action = action;
+    }
+}

src/me/topchetoeu/jscript/engine/values/NativeWrapper.java

@@ -1,19 +1,32 @@
-package me.topchetoeu.jscript.engine.values;
-
-import me.topchetoeu.jscript.engine.Context;
-
-public class NativeWrapper extends ObjectValue {
-    private static final Object NATIVE_PROTO = new Object();
-    public final Object wrapped;
-
-    @Override
-    public ObjectValue getPrototype(Context ctx) {
-        if (prototype == NATIVE_PROTO) return ctx.environment().wrappers.getProto(wrapped.getClass());
-        else return super.getPrototype(ctx);
-    }
-
-    public NativeWrapper(Object wrapped) {
-        this.wrapped = wrapped;
-        prototype = NATIVE_PROTO;
-    }
-}
+package me.topchetoeu.jscript.engine.values;
+
+import me.topchetoeu.jscript.engine.Context;
+
+public class NativeWrapper extends ObjectValue {
+    private static final Object NATIVE_PROTO = new Object();
+    public final Object wrapped;
+
+    @Override
+    public ObjectValue getPrototype(Context ctx) {
+        if (prototype == NATIVE_PROTO) return ctx.environment.wrappers.getProto(wrapped.getClass());
+        else return super.getPrototype(ctx);
+    }
+
+    @Override
+    public String toString() {
+        return wrapped.toString();
+    }
+    @Override
+    public boolean equals(Object obj) {
+        return wrapped.equals(obj);
+    }
+    @Override
+    public int hashCode() {
+        return wrapped.hashCode();
+    }
+
+    public NativeWrapper(Object wrapped) {
+        this.wrapped = wrapped;
+        prototype = NATIVE_PROTO;
+    }
+}

src/me/topchetoeu/jscript/engine/values/ObjectValue.java

@@ -1,345 +1,345 @@
-package me.topchetoeu.jscript.engine.values;
-
-import java.util.ArrayList;
-import java.util.LinkedHashMap;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Map;
-
-import me.topchetoeu.jscript.engine.Context;
-
-public class ObjectValue {
-    public static enum PlaceholderProto {
-        NONE,
-        OBJECT,
-        ARRAY,
-        FUNCTION,
-        ERROR,
-        SYNTAX_ERROR,
-        TYPE_ERROR,
-        RANGE_ERROR,
-    }
-    public static enum State {
-        NORMAL,
-        NO_EXTENSIONS,
-        SEALED,
-        FROZEN,
-    }
-
-    public static class Property { 
-        public final FunctionValue getter;
-        public final FunctionValue setter;
-
-        public Property(FunctionValue getter, FunctionValue setter) {
-            this.getter = getter;
-            this.setter = setter;
-        }
-    }
-
-    private static final Object OBJ_PROTO = new Object();
-    private static final Object ARR_PROTO = new Object();
-    private static final Object FUNC_PROTO = new Object();
-    private static final Object ERR_PROTO = new Object();
-    private static final Object SYNTAX_ERR_PROTO = new Object();
-    private static final Object TYPE_ERR_PROTO = new Object();
-    private static final Object RANGE_ERR_PROTO = new Object();
-
-    protected Object prototype;
-
-    public State state = State.NORMAL;
-    public LinkedHashMap<Object, Object> values = new LinkedHashMap<>();
-    public LinkedHashMap<Object, Property> properties = new LinkedHashMap<>();
-    public LinkedHashSet<Object> nonWritableSet = new LinkedHashSet<>();
-    public LinkedHashSet<Object> nonConfigurableSet = new LinkedHashSet<>();
-    public LinkedHashSet<Object> nonEnumerableSet = new LinkedHashSet<>();
-
-    public final boolean memberWritable(Object key) {
-        if (state == State.FROZEN) return false;
-        return !values.containsKey(key) || !nonWritableSet.contains(key);
-    }
-    public final boolean memberConfigurable(Object key) {
-        if (state == State.SEALED || state == State.FROZEN) return false;
-        return !nonConfigurableSet.contains(key);
-    }
-    public final boolean memberEnumerable(Object key) {
-        return !nonEnumerableSet.contains(key);
-    }
-    public final boolean extensible() {
-        return state == State.NORMAL;
-    }
-
-    public final void preventExtensions() {
-        if (state == State.NORMAL) state = State.NO_EXTENSIONS;
-    }
-    public final void seal() {
-        if (state == State.NORMAL || state == State.NO_EXTENSIONS) state = State.SEALED;
-    }
-    public final void freeze() {
-        state = State.FROZEN;
-    }
-
-    public final boolean defineProperty(Context ctx, Object key, Object val, boolean writable, boolean configurable, boolean enumerable) {
-        key = Values.normalize(ctx, key); val = Values.normalize(ctx, val);
-        boolean reconfigured = 
-            writable != memberWritable(key) ||
-            configurable != memberConfigurable(key) ||
-            enumerable != memberEnumerable(key);
-
-        if (!reconfigured) {
-            if (!memberWritable(key)) {
-                var a = values.get(key);
-                var b = val;
-                if (a == null || b == null) return a == null && b == null;
-                return a == b || a.equals(b);
-            }
-            values.put(key, val);
-            return true;
-        }
-
-        if (
-            properties.containsKey(key) &&
-            values.get(key) == val &&
-            !reconfigured
-        ) return true;
-
-        if (!extensible() && !values.containsKey(key) && !properties.containsKey(key)) return false;
-        if (!memberConfigurable(key))
-            return false;
-
-        nonWritableSet.remove(key);
-        nonEnumerableSet.remove(key);
-        properties.remove(key);
-        values.remove(key);
-
-        if (!writable) nonWritableSet.add(key);
-        if (!configurable) nonConfigurableSet.add(key);
-        if (!enumerable) nonEnumerableSet.add(key);
-
-        values.put(key, val);
-        return true;
-    }
-    public final boolean defineProperty(Context ctx, Object key, Object val) {
-        return defineProperty(ctx, key, val, true, true, true);
-    }
-    public final boolean defineProperty(Context ctx, Object key, FunctionValue getter, FunctionValue setter, boolean configurable, boolean enumerable) {
-        key = Values.normalize(ctx, key);
-        if (
-            properties.containsKey(key) &&
-            properties.get(key).getter == getter &&
-            properties.get(key).setter == setter &&
-            !configurable == nonConfigurableSet.contains(key) &&
-            !enumerable == nonEnumerableSet.contains(key)
-        ) return true;
-        if (!extensible() && !values.containsKey(key) && !properties.containsKey(key)) return false;
-        if (!memberConfigurable(key)) return false;
-
-        nonWritableSet.remove(key);
-        nonEnumerableSet.remove(key);
-        properties.remove(key);
-        values.remove(key);
-
-        if (!configurable) nonConfigurableSet.add(key);
-        if (!enumerable) nonEnumerableSet.add(key);
-
-        properties.put(key, new Property(getter, setter));
-        return true;
-    }
-
-    public ObjectValue getPrototype(Context ctx) {
-        try {
-            if (prototype == OBJ_PROTO) return ctx.environment().proto("object");
-            if (prototype == ARR_PROTO) return ctx.environment().proto("array");
-            if (prototype == FUNC_PROTO) return ctx.environment().proto("function");
-            if (prototype == ERR_PROTO) return ctx.environment().proto("error");
-            if (prototype == RANGE_ERR_PROTO) return ctx.environment().proto("rangeErr");
-            if (prototype == SYNTAX_ERR_PROTO) return ctx.environment().proto("syntaxErr");
-            if (prototype == TYPE_ERR_PROTO) return ctx.environment().proto("typeErr");
-        }
-        catch (NullPointerException e) { return null; }
-
-        return (ObjectValue)prototype;
-    }
-    public final boolean setPrototype(Context ctx, Object val) {
-        val = Values.normalize(ctx, val);
-
-        if (!extensible()) return false;
-        if (val == null || val == Values.NULL) {
-            prototype = null;
-            return true;
-        }
-        else if (Values.isObject(val)) {
-            var obj = Values.object(val);
-
-            if (ctx != null && ctx.environment() != null) {
-                if (obj == ctx.environment().proto("object")) prototype = OBJ_PROTO;
-                else if (obj == ctx.environment().proto("array")) prototype = ARR_PROTO;
-                else if (obj == ctx.environment().proto("function")) prototype = FUNC_PROTO;
-                else if (obj == ctx.environment().proto("error")) prototype = ERR_PROTO;
-                else if (obj == ctx.environment().proto("syntaxErr")) prototype = SYNTAX_ERR_PROTO;
-                else if (obj == ctx.environment().proto("typeErr")) prototype = TYPE_ERR_PROTO;
-                else if (obj == ctx.environment().proto("rangeErr")) prototype = RANGE_ERR_PROTO;
-                else prototype = obj;
-            }
-            else prototype = obj;
-
-            return true;
-        }
-        return false;
-    }
-    public final boolean setPrototype(PlaceholderProto val) {
-        if (!extensible()) return false;
-        switch (val) {
-            case OBJECT: prototype = OBJ_PROTO; break;
-            case FUNCTION: prototype = FUNC_PROTO; break;
-            case ARRAY: prototype = ARR_PROTO; break;
-            case ERROR: prototype = ERR_PROTO; break;
-            case SYNTAX_ERROR: prototype = SYNTAX_ERR_PROTO; break;
-            case TYPE_ERROR: prototype = TYPE_ERR_PROTO; break;
-            case RANGE_ERROR: prototype = RANGE_ERR_PROTO; break;
-            case NONE: prototype = null; break;
-        }
-        return true;
-    }
-
-    protected Property getProperty(Context ctx, Object key) {
-        if (properties.containsKey(key)) return properties.get(key);
-        var proto = getPrototype(ctx);
-        if (proto != null) return proto.getProperty(ctx, key);
-        else return null;
-    }
-    protected Object getField(Context ctx, Object key) {
-        if (values.containsKey(key)) return values.get(key);
-        var proto = getPrototype(ctx);
-        if (proto != null) return proto.getField(ctx, key);
-        else return null;
-    }
-    protected boolean setField(Context ctx, Object key, Object val) {
-        if (val instanceof FunctionValue && ((FunctionValue)val).name.equals("")) {
-            ((FunctionValue)val).name = Values.toString(ctx, key);
-        }
-
-        values.put(key, val);
-        return true;
-    }
-    protected void deleteField(Context ctx, Object key) {
-        values.remove(key);
-    }
-    protected boolean hasField(Context ctx, Object key) {
-        return values.containsKey(key);
-    }
-
-    public final Object getMember(Context ctx, Object key, Object thisArg) {
-        key = Values.normalize(ctx, key);
-
-        if ("__proto__".equals(key)) {
-            var res = getPrototype(ctx);
-            return res == null ? Values.NULL : res;
-        }
-
-        var prop = getProperty(ctx, key);
-
-        if (prop != null) {
-            if (prop.getter == null) return null;
-            else return prop.getter.call(ctx, Values.normalize(ctx, thisArg));
-        }
-        else return getField(ctx, key);
-    }
-    public final Object getMember(Context ctx, Object key) {
-        return getMember(ctx, key, this);
-    }
-
-    public final boolean setMember(Context ctx, Object key, Object val, Object thisArg, boolean onlyProps) {
-        key = Values.normalize(ctx, key); val = Values.normalize(ctx, val);
-
-        var prop = getProperty(ctx, key);
-        if (prop != null) {
-            if (prop.setter == null) return false;
-            prop.setter.call(ctx, Values.normalize(ctx, thisArg), val);
-            return true;
-        }
-        else if (onlyProps) return false;
-        else if (!extensible() && !values.containsKey(key)) return false;
-        else if (key == null) {
-            values.put(key, val);
-            return true;
-        }
-        else if (key.equals("__proto__")) return setPrototype(ctx, val);
-        else if (nonWritableSet.contains(key)) return false;
-        else return setField(ctx, key, val);
-    }
-    public final boolean setMember(Context ctx, Object key, Object val, boolean onlyProps) {
-        return setMember(ctx, Values.normalize(ctx, key), Values.normalize(ctx, val), this, onlyProps);
-    }
-
-    public final boolean hasMember(Context ctx, Object key, boolean own) {
-        key = Values.normalize(ctx, key);
-
-        if (key != null && key.equals("__proto__")) return true;
-        if (hasField(ctx, key)) return true;
-        if (properties.containsKey(key)) return true;
-        if (own) return false;
-        var proto = getPrototype(ctx);
-        return proto != null && proto.hasMember(ctx, key, own);
-    }
-    public final boolean deleteMember(Context ctx, Object key) {
-        key = Values.normalize(ctx, key);
-
-        if (!memberConfigurable(key)) return false;
-        properties.remove(key);
-        nonWritableSet.remove(key);
-        nonEnumerableSet.remove(key);
-        deleteField(ctx, key);
-        return true;
-    }
-
-    public final ObjectValue getMemberDescriptor(Context ctx, Object key) {
-        key = Values.normalize(ctx, key);
-
-        var prop = properties.get(key);
-        var res = new ObjectValue();
-
-        res.defineProperty(ctx, "configurable", memberConfigurable(key));
-        res.defineProperty(ctx, "enumerable", memberEnumerable(key));
-
-        if (prop != null) {
-            res.defineProperty(ctx, "get", prop.getter);
-            res.defineProperty(ctx, "set", prop.setter);
-        }
-        else if (hasField(ctx, key)) {
-            res.defineProperty(ctx, "value", values.get(key));
-            res.defineProperty(ctx, "writable", memberWritable(key));
-        }
-        else return null;
-        return res;
-    }
-
-    public List<Object> keys(boolean includeNonEnumerable) {
-        var res = new ArrayList<Object>();
-
-        for (var key : values.keySet()) {
-            if (nonEnumerableSet.contains(key) && !includeNonEnumerable) continue;
-            res.add(key);
-        }
-        for (var key : properties.keySet()) {
-            if (nonEnumerableSet.contains(key) && !includeNonEnumerable) continue;
-            res.add(key);
-        }
-
-        return res;
-    }
-
-    public ObjectValue(Context ctx, Map<?, ?> values) {
-        this(PlaceholderProto.OBJECT);
-        for (var el : values.entrySet()) {
-            defineProperty(ctx, el.getKey(), el.getValue());
-        }
-    }
-    public ObjectValue(PlaceholderProto proto) {
-        nonConfigurableSet.add("__proto__");
-        nonEnumerableSet.add("__proto__");
-        setPrototype(proto);
-    }
-    public ObjectValue() {
-        this(PlaceholderProto.OBJECT);
-    }
-}
+package me.topchetoeu.jscript.engine.values;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.Environment;
+
+public class ObjectValue {
+    public static enum PlaceholderProto {
+        NONE,
+        OBJECT,
+        ARRAY,
+        FUNCTION,
+        ERROR,
+        SYNTAX_ERROR,
+        TYPE_ERROR,
+        RANGE_ERROR,
+    }
+    public static enum State {
+        NORMAL,
+        NO_EXTENSIONS,
+        SEALED,
+        FROZEN,
+    }
+
+    public static class Property { 
+        public final FunctionValue getter;
+        public final FunctionValue setter;
+
+        public Property(FunctionValue getter, FunctionValue setter) {
+            this.getter = getter;
+            this.setter = setter;
+        }
+    }
+
+    private static final Object OBJ_PROTO = new Object();
+    private static final Object ARR_PROTO = new Object();
+    private static final Object FUNC_PROTO = new Object();
+    private static final Object ERR_PROTO = new Object();
+    private static final Object SYNTAX_ERR_PROTO = new Object();
+    private static final Object TYPE_ERR_PROTO = new Object();
+    private static final Object RANGE_ERR_PROTO = new Object();
+
+    protected Object prototype;
+
+    public State state = State.NORMAL;
+    public LinkedHashMap<Object, Object> values = new LinkedHashMap<>();
+    public LinkedHashMap<Object, Property> properties = new LinkedHashMap<>();
+    public LinkedHashSet<Object> nonWritableSet = new LinkedHashSet<>();
+    public LinkedHashSet<Object> nonConfigurableSet = new LinkedHashSet<>();
+    public LinkedHashSet<Object> nonEnumerableSet = new LinkedHashSet<>();
+
+    public final boolean memberWritable(Object key) {
+        if (state == State.FROZEN) return false;
+        return !values.containsKey(key) || !nonWritableSet.contains(key);
+    }
+    public final boolean memberConfigurable(Object key) {
+        if (state == State.SEALED || state == State.FROZEN) return false;
+        return !nonConfigurableSet.contains(key);
+    }
+    public final boolean memberEnumerable(Object key) {
+        return !nonEnumerableSet.contains(key);
+    }
+    public final boolean extensible() {
+        return state == State.NORMAL;
+    }
+
+    public final void preventExtensions() {
+        if (state == State.NORMAL) state = State.NO_EXTENSIONS;
+    }
+    public final void seal() {
+        if (state == State.NORMAL || state == State.NO_EXTENSIONS) state = State.SEALED;
+    }
+    public final void freeze() {
+        state = State.FROZEN;
+    }
+
+    public final boolean defineProperty(Context ctx, Object key, Object val, boolean writable, boolean configurable, boolean enumerable) {
+        key = Values.normalize(ctx, key); val = Values.normalize(ctx, val);
+        boolean reconfigured = 
+            writable != memberWritable(key) ||
+            configurable != memberConfigurable(key) ||
+            enumerable != memberEnumerable(key);
+
+        if (!reconfigured) {
+            if (!memberWritable(key)) {
+                var a = values.get(key);
+                var b = val;
+                if (a == null || b == null) return a == null && b == null;
+                return a == b || a.equals(b);
+            }
+            values.put(key, val);
+            return true;
+        }
+
+        if (
+            properties.containsKey(key) &&
+            values.get(key) == val &&
+            !reconfigured
+        ) return true;
+
+        if (!extensible() && !values.containsKey(key) && !properties.containsKey(key)) return false;
+        if (!memberConfigurable(key)) return false;
+
+        nonWritableSet.remove(key);
+        nonEnumerableSet.remove(key);
+        properties.remove(key);
+        values.remove(key);
+
+        if (!writable) nonWritableSet.add(key);
+        if (!configurable) nonConfigurableSet.add(key);
+        if (!enumerable) nonEnumerableSet.add(key);
+
+        values.put(key, val);
+        return true;
+    }
+    public final boolean defineProperty(Context ctx, Object key, Object val) {
+        return defineProperty(ctx, key, val, true, true, true);
+    }
+    public final boolean defineProperty(Context ctx, Object key, FunctionValue getter, FunctionValue setter, boolean configurable, boolean enumerable) {
+        key = Values.normalize(ctx, key);
+        if (
+            properties.containsKey(key) &&
+            properties.get(key).getter == getter &&
+            properties.get(key).setter == setter &&
+            !configurable == nonConfigurableSet.contains(key) &&
+            !enumerable == nonEnumerableSet.contains(key)
+        ) return true;
+        if (!extensible() && !values.containsKey(key) && !properties.containsKey(key)) return false;
+        if (!memberConfigurable(key)) return false;
+
+        nonWritableSet.remove(key);
+        nonEnumerableSet.remove(key);
+        properties.remove(key);
+        values.remove(key);
+
+        if (!configurable) nonConfigurableSet.add(key);
+        if (!enumerable) nonEnumerableSet.add(key);
+
+        properties.put(key, new Property(getter, setter));
+        return true;
+    }
+
+    public ObjectValue getPrototype(Context ctx) {
+        try {
+            if (prototype == OBJ_PROTO) return ctx.get(Environment.OBJECT_PROTO);
+            if (prototype == ARR_PROTO) return ctx.get(Environment.ARRAY_PROTO);
+            if (prototype == FUNC_PROTO) return ctx.get(Environment.FUNCTION_PROTO);
+            if (prototype == ERR_PROTO) return ctx.get(Environment.ERROR_PROTO);
+            if (prototype == RANGE_ERR_PROTO) return ctx.get(Environment.RANGE_ERR_PROTO);
+            if (prototype == SYNTAX_ERR_PROTO) return ctx.get(Environment.SYNTAX_ERR_PROTO);
+            if (prototype == TYPE_ERR_PROTO) return ctx.get(Environment.TYPE_ERR_PROTO);
+        }
+        catch (NullPointerException e) { return null; }
+
+        return (ObjectValue)prototype;
+    }
+    public final boolean setPrototype(Context ctx, Object val) {
+        val = Values.normalize(ctx, val);
+
+        if (!extensible()) return false;
+        if (val == null || val == Values.NULL) {
+            prototype = null;
+            return true;
+        }
+        else if (val instanceof ObjectValue) {
+            var obj = Values.object(val);
+
+            if (ctx != null) {
+                if (obj == ctx.get(Environment.OBJECT_PROTO)) prototype = OBJ_PROTO;
+                else if (obj == ctx.get(Environment.ARRAY_PROTO)) prototype = ARR_PROTO;
+                else if (obj == ctx.get(Environment.FUNCTION_PROTO)) prototype = FUNC_PROTO;
+                else if (obj == ctx.get(Environment.ERROR_PROTO)) prototype = ERR_PROTO;
+                else if (obj == ctx.get(Environment.SYNTAX_ERR_PROTO)) prototype = SYNTAX_ERR_PROTO;
+                else if (obj == ctx.get(Environment.TYPE_ERR_PROTO)) prototype = TYPE_ERR_PROTO;
+                else if (obj == ctx.get(Environment.RANGE_ERR_PROTO)) prototype = RANGE_ERR_PROTO;
+                else prototype = obj;
+            }
+            else prototype = obj;
+
+            return true;
+        }
+        return false;
+    }
+    public final boolean setPrototype(PlaceholderProto val) {
+        if (!extensible()) return false;
+        switch (val) {
+            case OBJECT: prototype = OBJ_PROTO; break;
+            case FUNCTION: prototype = FUNC_PROTO; break;
+            case ARRAY: prototype = ARR_PROTO; break;
+            case ERROR: prototype = ERR_PROTO; break;
+            case SYNTAX_ERROR: prototype = SYNTAX_ERR_PROTO; break;
+            case TYPE_ERROR: prototype = TYPE_ERR_PROTO; break;
+            case RANGE_ERROR: prototype = RANGE_ERR_PROTO; break;
+            case NONE: prototype = null; break;
+        }
+        return true;
+    }
+
+    protected Property getProperty(Context ctx, Object key) {
+        if (properties.containsKey(key)) return properties.get(key);
+        var proto = getPrototype(ctx);
+        if (proto != null) return proto.getProperty(ctx, key);
+        else return null;
+    }
+    protected Object getField(Context ctx, Object key) {
+        if (values.containsKey(key)) return values.get(key);
+        var proto = getPrototype(ctx);
+        if (proto != null) return proto.getField(ctx, key);
+        else return null;
+    }
+    protected boolean setField(Context ctx, Object key, Object val) {
+        if (val instanceof FunctionValue && ((FunctionValue)val).name.equals("")) {
+            ((FunctionValue)val).name = Values.toString(ctx, key);
+        }
+
+        values.put(key, val);
+        return true;
+    }
+    protected void deleteField(Context ctx, Object key) {
+        values.remove(key);
+    }
+    protected boolean hasField(Context ctx, Object key) {
+        return values.containsKey(key);
+    }
+
+    public final Object getMember(Context ctx, Object key, Object thisArg) {
+        key = Values.normalize(ctx, key);
+
+        if ("__proto__".equals(key)) {
+            var res = getPrototype(ctx);
+            return res == null ? Values.NULL : res;
+        }
+
+        var prop = getProperty(ctx, key);
+
+        if (prop != null) {
+            if (prop.getter == null) return null;
+            else return prop.getter.call(ctx, Values.normalize(ctx, thisArg));
+        }
+        else return getField(ctx, key);
+    }
+    public final Object getMember(Context ctx, Object key) {
+        return getMember(ctx, key, this);
+    }
+
+    public final boolean setMember(Context ctx, Object key, Object val, Object thisArg, boolean onlyProps) {
+        key = Values.normalize(ctx, key); val = Values.normalize(ctx, val);
+
+        var prop = getProperty(ctx, key);
+        if (prop != null) {
+            if (prop.setter == null) return false;
+            prop.setter.call(ctx, Values.normalize(ctx, thisArg), val);
+            return true;
+        }
+        else if (onlyProps) return false;
+        else if (!extensible() && !values.containsKey(key)) return false;
+        else if (key == null) {
+            values.put(key, val);
+            return true;
+        }
+        else if ("__proto__".equals(key)) return setPrototype(ctx, val);
+        else if (nonWritableSet.contains(key)) return false;
+        else return setField(ctx, key, val);
+    }
+    public final boolean setMember(Context ctx, Object key, Object val, boolean onlyProps) {
+        return setMember(ctx, Values.normalize(ctx, key), Values.normalize(ctx, val), this, onlyProps);
+    }
+
+    public final boolean hasMember(Context ctx, Object key, boolean own) {
+        key = Values.normalize(ctx, key);
+
+        if (key != null && "__proto__".equals(key)) return true;
+        if (hasField(ctx, key)) return true;
+        if (properties.containsKey(key)) return true;
+        if (own) return false;
+        var proto = getPrototype(ctx);
+        return proto != null && proto.hasMember(ctx, key, own);
+    }
+    public final boolean deleteMember(Context ctx, Object key) {
+        key = Values.normalize(ctx, key);
+
+        if (!memberConfigurable(key)) return false;
+        properties.remove(key);
+        nonWritableSet.remove(key);
+        nonEnumerableSet.remove(key);
+        deleteField(ctx, key);
+        return true;
+    }
+
+    public final ObjectValue getMemberDescriptor(Context ctx, Object key) {
+        key = Values.normalize(ctx, key);
+
+        var prop = properties.get(key);
+        var res = new ObjectValue();
+
+        res.defineProperty(ctx, "configurable", memberConfigurable(key));
+        res.defineProperty(ctx, "enumerable", memberEnumerable(key));
+
+        if (prop != null) {
+            res.defineProperty(ctx, "get", prop.getter);
+            res.defineProperty(ctx, "set", prop.setter);
+        }
+        else if (hasField(ctx, key)) {
+            res.defineProperty(ctx, "value", values.get(key));
+            res.defineProperty(ctx, "writable", memberWritable(key));
+        }
+        else return null;
+        return res;
+    }
+
+    public List<Object> keys(boolean includeNonEnumerable) {
+        var res = new ArrayList<Object>();
+
+        for (var key : values.keySet()) {
+            if (nonEnumerableSet.contains(key) && !includeNonEnumerable) continue;
+            res.add(key);
+        }
+        for (var key : properties.keySet()) {
+            if (nonEnumerableSet.contains(key) && !includeNonEnumerable) continue;
+            res.add(key);
+        }
+
+        return res;
+    }
+
+    public ObjectValue(Context ctx, Map<?, ?> values) {
+        this(PlaceholderProto.OBJECT);
+        for (var el : values.entrySet()) {
+            defineProperty(ctx, el.getKey(), el.getValue());
+        }
+    }
+    public ObjectValue(PlaceholderProto proto) {
+        nonConfigurableSet.add("__proto__");
+        nonEnumerableSet.add("__proto__");
+        setPrototype(proto);
+    }
+    public ObjectValue() {
+        this(PlaceholderProto.OBJECT);
+    }
+}

src/me/topchetoeu/jscript/engine/values/ScopeValue.java

@@ -22,6 +22,9 @@ public class ScopeValue extends ObjectValue {
             return true;
         }
 
+        var proto = getPrototype(ctx);
+        if (proto != null && proto.hasField(ctx, key) && proto.setField(ctx, key, val)) return true;
+
         return super.setField(ctx, key, val);
     }
     @Override

src/me/topchetoeu/jscript/engine/values/Symbol.java

@@ -1,15 +1,28 @@
-package me.topchetoeu.jscript.engine.values;
-
-public final class Symbol {
-    public final String value;
-
-    public Symbol(String value) {
-        this.value = value;
-    }
-
-    @Override
-    public String toString() {
-        if (value == null) return "Symbol";
-        else return "@@" + value;
-    }
-}
+package me.topchetoeu.jscript.engine.values;
+
+import java.util.HashMap;
+
+public final class Symbol {
+    private static final HashMap<String, Symbol> registry = new HashMap<>();
+
+    public final String value;
+
+    public Symbol(String value) {
+        this.value = value;
+    }
+
+    @Override
+    public String toString() {
+        if (value == null) return "Symbol";
+        else return "@@" + value;
+    }
+
+    public static Symbol get(String name) {
+        if (registry.containsKey(name)) return registry.get(name);
+        else {
+            var res = new Symbol(name);
+            registry.put(name, res);
+            return res;
+        }
+    }
+}

src/me/topchetoeu/jscript/engine/values/Values.java

@@ -11,19 +11,36 @@ import java.util.List;
 import java.util.Map;
 
 import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.Environment;
 import me.topchetoeu.jscript.engine.Operation;
 import me.topchetoeu.jscript.engine.frame.ConvertHint;
 import me.topchetoeu.jscript.exceptions.ConvertException;
 import me.topchetoeu.jscript.exceptions.EngineException;
 import me.topchetoeu.jscript.exceptions.SyntaxException;
-import me.topchetoeu.jscript.exceptions.UncheckedException;
+import me.topchetoeu.jscript.lib.PromiseLib;
 
 public class Values {
-    public static final Object NULL = new Object();
+    public static enum CompareResult {
+        NOT_EQUAL,
+        EQUAL,
+        LESS,
+        GREATER;
+
+        public boolean less() { return this == LESS; }
+        public boolean greater() { return this == GREATER; }
+        public boolean lessOrEqual() { return this == LESS || this == EQUAL; }
+        public boolean greaterOrEqual() { return this == GREATER || this == EQUAL; }
+
+        public static CompareResult from(int cmp) {
+            if (cmp < 0) return LESS;
+            if (cmp > 0) return GREATER;
+            return EQUAL;
+        }
+    }
+
+    public static final Object NULL = new Object();
+    public static final Object NO_RETURN = new Object();
 
-    public static boolean isObject(Object val) { return val instanceof ObjectValue; }
-    public static boolean isFunction(Object val) { return val instanceof FunctionValue; }
-    public static boolean isArray(Object val) { return val instanceof ArrayValue; }
     public static boolean isWrapper(Object val) { return val instanceof NativeWrapper; }
     public static boolean isWrapper(Object val, Class<?> clazz) {
         if (!isWrapper(val)) return false;
@@ -51,8 +68,7 @@ public class Values {
 
     @SuppressWarnings("unchecked")
     public static <T> T wrapper(Object val, Class<T> clazz) { 
-        if (!isWrapper(val)) return null;
-
+        if (!isWrapper(val)) val = new NativeWrapper(val);
         var res = (NativeWrapper)val;
         if (res != null && clazz.isInstance(res.wrapped)) return (T)res.wrapped;
         else return null;
@@ -71,8 +87,8 @@ public class Values {
     private static Object tryCallConvertFunc(Context ctx, Object obj, String name) {
         var func = getMember(ctx, obj, name);
 
-        if (func != null) {
-            var res = ((FunctionValue)func).call(ctx, obj);
+        if (func instanceof FunctionValue) {
+            var res = Values.call(ctx, func, obj);
             if (isPrimitive(res)) return res;
         }
 
@@ -105,7 +121,7 @@ public class Values {
     }
     public static boolean toBoolean(Object obj) {
         if (obj == NULL || obj == null) return false;
-        if (obj instanceof Number && number(obj) == 0) return false;
+        if (obj instanceof Number && (number(obj) == 0 || Double.isNaN(number(obj)))) return false;
         if (obj instanceof String && ((String)obj).equals("")) return false;
         if (obj instanceof Boolean) return (Boolean)obj;
         return true;
@@ -117,7 +133,7 @@ public class Values {
         if (val instanceof Boolean) return ((Boolean)val) ? 1 : 0;
         if (val instanceof String) {
             try { return Double.parseDouble((String)val); }
-            catch (Throwable e) { throw new UncheckedException(e); }
+            catch (NumberFormatException e) { return Double.NaN; }
         }
         return Double.NaN;
     }
@@ -136,7 +152,7 @@ public class Values {
         }
         if (val instanceof Boolean) return (Boolean)val ? "true" : "false";
         if (val instanceof String) return (String)val;
-        if (val instanceof Symbol) return ((Symbol)val).toString();
+        if (val instanceof Symbol) return val.toString();
 
         return "Unknown value";
     }
@@ -190,12 +206,18 @@ public class Values {
         return _a >>> _b;
     }
 
-    public static int compare(Context ctx, Object a, Object b) {
+    public static CompareResult compare(Context ctx, Object a, Object b) {
         a = toPrimitive(ctx, a, ConvertHint.VALUEOF);
         b = toPrimitive(ctx, b, ConvertHint.VALUEOF);
 
-        if (a instanceof String && b instanceof String) return ((String)a).compareTo((String)b);
-        else return Double.compare(toNumber(ctx, a), toNumber(ctx, b));
+        if (a instanceof String && b instanceof String) CompareResult.from(((String)a).compareTo((String)b));
+
+        var _a = toNumber(ctx, a);
+        var _b = toNumber(ctx, b);
+
+        if (Double.isNaN(_a) || Double.isNaN(_b)) return CompareResult.NOT_EQUAL;
+
+        return CompareResult.from(Double.compare(_a, _b));
     }
 
     public static boolean not(Object obj) {
@@ -231,10 +253,10 @@ public class Values {
             case LOOSE_EQUALS: return looseEqual(ctx, args[0], args[1]);
             case LOOSE_NOT_EQUALS: return !looseEqual(ctx, args[0], args[1]);
 
-            case GREATER: return compare(ctx, args[0], args[1]) > 0;
-            case GREATER_EQUALS: return compare(ctx, args[0], args[1]) >= 0;
-            case LESS: return compare(ctx, args[0], args[1]) < 0;
-            case LESS_EQUALS: return compare(ctx, args[0], args[1]) <= 0;
+            case GREATER: return compare(ctx, args[0], args[1]).greater();
+            case GREATER_EQUALS: return compare(ctx, args[0], args[1]).greaterOrEqual();
+            case LESS: return compare(ctx, args[0], args[1]).less();
+            case LESS_EQUALS: return compare(ctx, args[0], args[1]).lessOrEqual();
 
             case INVERSE: return bitwiseNot(ctx, args[0]);
             case NOT: return not(args[0]);
@@ -259,7 +281,7 @@ public class Values {
         obj = normalize(ctx, obj); key = normalize(ctx, key);
         if (obj == null) throw new IllegalArgumentException("Tried to access member of undefined.");
         if (obj == NULL) throw new IllegalArgumentException("Tried to access member of null.");
-        if (isObject(obj)) return object(obj).getMember(ctx, key);
+        if (obj instanceof ObjectValue) return object(obj).getMember(ctx, key);
 
         if (obj instanceof String && key instanceof Number) {
             var i = number(key);
@@ -271,16 +293,21 @@ public class Values {
 
         var proto = getPrototype(ctx, obj);
 
-        if (proto == null) return key.equals("__proto__") ? NULL : null;
-        else if (key != null && key.equals("__proto__")) return proto;
+        if (proto == null) return "__proto__".equals(key) ? NULL : null;
+        else if (key != null && "__proto__".equals(key)) return proto;
         else return proto.getMember(ctx, key, obj);
     }
+    public static Object getMemberPath(Context ctx, Object obj, Object ...path) {
+        var res = obj;
+        for (var key : path) res = getMember(ctx, res, key);
+        return res;
+    }
     public static boolean setMember(Context ctx, Object obj, Object key, Object val) {
         obj = normalize(ctx, obj); key = normalize(ctx, key); val = normalize(ctx, val);
         if (obj == null) throw EngineException.ofType("Tried to access member of undefined.");
         if (obj == NULL) throw EngineException.ofType("Tried to access member of null.");
-        if (key.equals("__proto__")) return setPrototype(ctx, obj, val);
-        if (isObject(obj)) return object(obj).setMember(ctx, key, val, false);
+        if (key != null && "__proto__".equals(key)) return setPrototype(ctx, obj, val);
+        if (obj instanceof ObjectValue) return object(obj).setMember(ctx, key, val, false);
 
         var proto = getPrototype(ctx, obj);
         return proto.setMember(ctx, key, val, obj, true);
@@ -289,8 +316,8 @@ public class Values {
         if (obj == null || obj == NULL) return false;
         obj = normalize(ctx, obj); key = normalize(ctx, key);
 
-        if (key.equals("__proto__")) return true;
-        if (isObject(obj)) return object(obj).hasMember(ctx, key, own);
+        if ("__proto__".equals(key)) return true;
+        if (obj instanceof ObjectValue) return object(obj).hasMember(ctx, key, own);
 
         if (obj instanceof String && key instanceof Number) {
             var i = number(key);
@@ -307,30 +334,30 @@ public class Values {
         if (obj == null || obj == NULL) return false;
         obj = normalize(ctx, obj); key = normalize(ctx, key);
 
-        if (isObject(obj)) return object(obj).deleteMember(ctx, key);
+        if (obj instanceof ObjectValue) return object(obj).deleteMember(ctx, key);
         else return false;
     }
     public static ObjectValue getPrototype(Context ctx, Object obj) {
         if (obj == null || obj == NULL) return null;
         obj = normalize(ctx, obj);
-        if (isObject(obj)) return object(obj).getPrototype(ctx);
+        if (obj instanceof ObjectValue) return object(obj).getPrototype(ctx);
         if (ctx == null) return null;
 
-        if (obj instanceof String) return ctx.environment().proto("string");
-        else if (obj instanceof Number) return ctx.environment().proto("number");
-        else if (obj instanceof Boolean) return ctx.environment().proto("bool");
-        else if (obj instanceof Symbol) return ctx.environment().proto("symbol");
+        if (obj instanceof String) return ctx.get(Environment.STRING_PROTO);
+        else if (obj instanceof Number) return ctx.get(Environment.NUMBER_PROTO);
+        else if (obj instanceof Boolean) return ctx.get(Environment.BOOL_PROTO);
+        else if (obj instanceof Symbol) return ctx.get(Environment.SYMBOL_PROTO);
 
         return null;
     }
     public static boolean setPrototype(Context ctx, Object obj, Object proto) {
         obj = normalize(ctx, obj);
-        return isObject(obj) && object(obj).setPrototype(ctx, proto);
+        return obj instanceof ObjectValue && object(obj).setPrototype(ctx, proto);
     }
     public static List<Object> getMembers(Context ctx, Object obj, boolean own, boolean includeNonEnumerable) {  
         List<Object> res = new ArrayList<>();
 
-        if (isObject(obj)) res = object(obj).keys(includeNonEnumerable);
+        if (obj instanceof ObjectValue) res = object(obj).keys(includeNonEnumerable);
         if (obj instanceof String) {
             for (var i = 0; i < ((String)obj).length(); i++) res.add((double)i);
         }
@@ -366,18 +393,23 @@ public class Values {
     }
 
     public static Object call(Context ctx, Object func, Object thisArg, Object ...args) {
-        if (!isFunction(func)) throw EngineException.ofType("Tried to call a non-function value.");
+        if (!(func instanceof FunctionValue)) throw EngineException.ofType("Tried to call a non-function value.");
         return function(func).call(ctx, thisArg, args);
     }
     public static Object callNew(Context ctx, Object func, Object ...args) {
         var res = new ObjectValue();
-        var proto = Values.getMember(ctx, func, "prototype");
-        res.setPrototype(ctx, proto);
-
-        var ret = call(ctx, func, res, args);
-
-        if (ret != null && func instanceof FunctionValue && ((FunctionValue)func).special) return ret;
-        return res;
+        try {
+            var proto = Values.getMember(ctx, func, "prototype");
+            res.setPrototype(ctx, proto);
+    
+            var ret = call(ctx, func, res, args);
+    
+            if (ret != null && func instanceof FunctionValue && ((FunctionValue)func).special) return ret;
+            return res;
+        }
+        catch (IllegalArgumentException e) {
+            throw EngineException.ofType("Tried to call new on an invalid constructor.");
+        }
     }
 
     public static boolean strictEquals(Context ctx, Object a, Object b) {
@@ -441,7 +473,7 @@ public class Values {
 
         if (val instanceof Class) {
             if (ctx == null) return null;
-            else return ctx.environment().wrappers.getConstr((Class<?>)val);
+            else return ctx.environment.wrappers.getConstr((Class<?>)val);
         }
 
         return new NativeWrapper(val);
@@ -508,23 +540,26 @@ public class Values {
 
         if (obj == null) return null;
         if (clazz.isInstance(obj)) return (T)obj;
+        if (clazz.isAssignableFrom(NativeWrapper.class)) {
+            return (T)new NativeWrapper(obj);
+        }
 
         throw new ConvertException(type(obj), clazz.getSimpleName());
     }
 
-    public static Iterable<Object> toJavaIterable(Context ctx, Object obj) {
+    public static Iterable<Object> fromJSIterator(Context ctx, Object obj) {
         return () -> {
             try {
-                var symbol = ctx.environment().symbol("Symbol.iterator");
+                var symbol = Symbol.get("Symbol.iterator");
 
                 var iteratorFunc = getMember(ctx, obj, symbol);
-                if (!isFunction(iteratorFunc)) return Collections.emptyIterator();
+                if (!(iteratorFunc instanceof FunctionValue)) return Collections.emptyIterator();
                 var iterator = iteratorFunc instanceof FunctionValue ?
                     ((FunctionValue)iteratorFunc).call(ctx, obj, obj) :
                     iteratorFunc;
                 var nextFunc = getMember(ctx, call(ctx, iteratorFunc, obj), "next");
 
-                if (!isFunction(nextFunc)) return Collections.emptyIterator();
+                if (!(nextFunc instanceof FunctionValue)) return Collections.emptyIterator();
 
                 return new Iterator<Object>() {
                     private Object value = null;
@@ -565,28 +600,70 @@ public class Values {
         };
     }
 
-    public static ObjectValue fromJavaIterator(Context ctx, Iterator<?> it) {
+    public static ObjectValue toJSIterator(Context ctx, Iterator<?> it) {
         var res = new ObjectValue();
 
         try {
-            var key = getMember(ctx, getMember(ctx, ctx.environment().proto("symbol"), "constructor"), "iterator");
-            res.defineProperty(ctx, key, new NativeFunction("", (_ctx, thisArg, args) -> thisArg));
+            var key = getMember(ctx, getMember(ctx, ctx.get(Environment.SYMBOL_PROTO), "constructor"), "iterator");
+            res.defineProperty(ctx, key, new NativeFunction("", args -> args.self));
         }
         catch (IllegalArgumentException | NullPointerException e) { }
 
-        res.defineProperty(ctx, "next", new NativeFunction("", (_ctx, _th, _args) -> {
+        res.defineProperty(ctx, "next", new NativeFunction("", args -> {
             if (!it.hasNext()) return new ObjectValue(ctx, Map.of("done", true));
-            else return new ObjectValue(ctx, Map.of("value", it.next()));
+            else {
+                var obj = new ObjectValue();
+                obj.defineProperty(args.ctx, "value", it.next());
+                return obj;
+            }
         }));
 
         return res;
     }
 
-    public static ObjectValue fromJavaIterable(Context ctx, Iterable<?> it) {
-        return fromJavaIterator(ctx, it.iterator());
+    public static ObjectValue toJSIterator(Context ctx, Iterable<?> it) {
+        return toJSIterator(ctx, it.iterator());
     }
 
+    public static ObjectValue toJSAsyncIterator(Context ctx, Iterator<?> it) {
+        var res = new ObjectValue();
+
+        try {
+            var key = getMemberPath(ctx, ctx.get(Environment.SYMBOL_PROTO), "constructor", "asyncIterator");
+            res.defineProperty(ctx, key, new NativeFunction("", args -> args.self));
+        }
+        catch (IllegalArgumentException | NullPointerException e) { }
+
+        res.defineProperty(ctx, "next", new NativeFunction("", args -> {
+            return PromiseLib.await(args.ctx, () -> {
+                if (!it.hasNext()) return new ObjectValue(ctx, Map.of("done", true));
+                else {
+                    var obj = new ObjectValue();
+                    obj.defineProperty(args.ctx, "value", it.next());
+                    return obj;
+                }
+            });
+        }));
+
+        return res;
+    }
+
+    private static boolean isEmptyFunc(ObjectValue val) {
+        if (!(val instanceof FunctionValue)) return false;
+        if (!val.values.containsKey("prototype") || val.values.size() + val.properties.size() > 1) return false;
+        var proto = val.values.get("prototype");
+        if (!(proto instanceof ObjectValue)) return false;
+        var protoObj = (ObjectValue)proto;
+        if (protoObj.values.get("constructor") != val) return false;
+        if (protoObj.values.size() + protoObj.properties.size() != 1) return false;
+        return true;
+    }
     private static void printValue(Context ctx, Object val, HashSet<Object> passed, int tab) {
+        if (tab == 0 && val instanceof String) {
+            System.out.print(val);
+            return;
+        }
+
         if (passed.contains(val)) {
             System.out.print("[circular]");
             return;
@@ -595,10 +672,7 @@ public class Values {
         var printed = true;
 
         if (val instanceof FunctionValue) {
-            System.out.print("function ");
-            var name = Values.getMember(ctx, val, "name");
-            if (name != null) System.out.print(Values.toString(ctx, name));
-            System.out.print("(...)");
+            System.out.print(val.toString());
             var loc = val instanceof CodeFunction ? ((CodeFunction)val).loc() : null;
 
             if (loc != null) System.out.print(" @ " + loc);
@@ -628,7 +702,7 @@ public class Values {
             passed.add(val);
 
             var obj = (ObjectValue)val;
-            if (obj.values.size() + obj.properties.size() == 0) {
+            if (obj.values.size() + obj.properties.size() == 0 || isEmptyFunc(obj)) {
                 if (!printed) System.out.println("{}");
             }
             else {
@@ -646,12 +720,13 @@ public class Values {
                     printValue(ctx, el.getKey(), passed, tab + 1);
                     System.out.println(": [prop],");
                 }
-    
+
                 for (int i = 0; i < tab; i++) System.out.print("    ");
                 System.out.print("}");
-    
-                passed.remove(val);
+
             }
+
+            passed.remove(val);
         }
         else if (val == null) System.out.print("undefined");
         else if (val == Values.NULL) System.out.print("null");
@@ -666,7 +741,7 @@ public class Values {
         try {
             if (err instanceof EngineException) {
                 var ee = ((EngineException)err);
-                System.out.println(prefix + " " + ee.toString(new Context(ee.engine).pushEnv(ee.env)));
+                System.out.println(prefix + " " + ee.toString(new Context(ee.engine, ee.env)));
             }
             else if (err instanceof SyntaxException) {
                 System.out.println("Syntax error:" + ((SyntaxException)err).msg);

src/me/topchetoeu/jscript/events/Awaitable.java

@@ -1,25 +1,27 @@
-package me.topchetoeu.jscript.events;
-
-import me.topchetoeu.jscript.exceptions.InterruptException;
-
-public interface Awaitable<T> {
-    T await() throws FinishedException;
-
-    default Observable<T> toObservable() {
-        return sub -> {
-            var thread = new Thread(() -> {
-                try {
-                    sub.next(await());
-                    sub.finish();
-                }
-                catch (InterruptException | FinishedException e) { sub.finish(); }
-                catch (RuntimeException e) {
-                    sub.error(e);
-                }
-            }, "Awaiter");
-            thread.start();
-
-            return () -> thread.interrupt();
-        };
-    }
-}
+package me.topchetoeu.jscript.events;
+
+public interface Awaitable<T> {
+    public static interface ResultHandler<T> {
+        public void onResult(T data);
+    }
+    public static interface ErrorHandler {
+        public void onError(RuntimeException error);
+    }
+
+    T await();
+
+    default void handle(ResultHandler<T> onResult, ErrorHandler onError) {
+        var thread = new Thread(() -> {
+            try {
+                onResult.onResult(await());
+            }
+            catch (RuntimeException e) {
+                onError.onError(e);
+            }
+        }, "Awaiter");
+        thread.start();
+    }
+    default void handle(ResultHandler<T> onResult) {
+        handle(onResult, err -> {});
+    }
+}

src/me/topchetoeu/jscript/events/DataNotifier.java

@@ -1,34 +1,31 @@
-package me.topchetoeu.jscript.events;
-
-public class DataNotifier<T> implements Awaitable<T> {
-    private Notifier notifier = new Notifier();
-    private boolean isErr;
-    private T val;
-    private RuntimeException err;
-
-    public void error(RuntimeException t) {
-        err = t;
-        isErr = true;
-        notifier.next();
-    }
-    public void error(Throwable t) {
-        error(new RuntimeException(t));
-    }
-    public void next(T val) {
-        this.val = val;
-        isErr = false;
-        notifier.next();
-    }
-    public T await() {
-        notifier.await();
-
-        try {
-            if (isErr) throw err;
-            else return val;
-        }
-        finally {
-            this.err = null;
-            this.val = null;
-        }
-    }
-}
+package me.topchetoeu.jscript.events;
+
+public class DataNotifier<T> implements Awaitable<T> {
+    private Notifier notifier = new Notifier();
+    private boolean isErr;
+    private T val;
+    private RuntimeException err;
+
+    public void error(RuntimeException t) {
+        err = t;
+        isErr = true;
+        notifier.next();
+    }
+    public void next(T val) {
+        this.val = val;
+        isErr = false;
+        notifier.next();
+    }
+    public T await() {
+        notifier.await();
+
+        try {
+            if (isErr) throw err;
+            else return val;
+        }
+        finally {
+            this.err = null;
+            this.val = null;
+        }
+    }
+}

src/me/topchetoeu/jscript/events/Event.java

@@ -1,49 +0,0 @@
-package me.topchetoeu.jscript.events;
-
-import java.util.HashSet;
-
-public class Event<T> implements Observer<T>, Observable<T> {
-    private HashSet<Observer<T>> handlers = new HashSet<>();
-
-    public Handle on(Observer<T> handler) {
-        if (handlers == null) {
-            handler.finish();
-            return () -> {};
-        }
-
-        handlers.add(handler);
-        return () -> {
-            if (handlers == null) return;
-            handlers.remove(handler);
-        };
-    }
-
-    public boolean isFinished() {
-        return handlers == null;
-    }
-
-    public void next(T value) {
-        if (handlers == null) throw new IllegalStateException("Cannot use a finished event.");
-        for (var handler : handlers) {
-            handler.next(value);
-        }
-    }
-    public void error(RuntimeException value) {
-        if (handlers == null) throw new IllegalStateException("Cannot use a finished event.");
-        for (var handler : handlers) {
-            handler.error(value);
-        }
-
-        handlers.clear();
-        handlers = null;
-    }
-    public void finish() {
-        if (handlers == null) throw new IllegalStateException("Cannot use a finished event.");
-        for (var handler : handlers) {
-            handler.finish();
-        }
-
-        handlers.clear();
-        handlers = null;
-    }
-}