fix: make code java 11 compatible

Permissions and filesystems

.github/workflows/tagged-release.yml

@@ -15,7 +15,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'adopt'
-          java-version: '17'
+          java-version: '11'
       - name: Clone repository
         uses: GuillaumeFalourd/clone-github-repo-action@main
         with:

README.md

@@ -4,31 +4,42 @@
 
 **WARNING: Currently, this code is mostly 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`:
 
 ```java
-var engine = new PolyfillEngine(new File("."));
-var in = new BufferedReader(new InputStreamReader(System.in));
+var engine = new Engine(true /* false if you dont want debugging */);
+var env = new Environment(null, null, null);
+var debugger = new DebugServer();
+
+// Create one target for the engine and start debugging server
+debugger.targets.put("target", (socket, req) -> new SimpleDebugger(socket, engine));
+debugger.start(new InetSocketAddress("127.0.0.1", 9229), true);
+
+// Queue code to load internal libraries and start engine
+engine.pushMsg(false, null, new Internals().getApplier(env));
 engine.start();
 
 while (true) {
     try {
-        var raw = in.readLine();
+        var raw = Reading.read();
+        if (raw == null) break;
 
-        var res = engine.pushMsg(false, engine.global(), Map.of(), "<stdio>", raw, null).await();
-        Values.printValue(engine.context(), res);
-        System.out.println();
+        // Push a message to the engine with the raw REPL code
+        var res = engine.pushMsg(
+            false, new Context(engine).pushEnv(env),
+            new Filename("jscript", "repl.js"), raw, null
+        ).await();
+
+        Values.printValue(null, res);
     }
-    catch (EngineException e) {
-        try {
-            System.out.println("Uncaught " + e.toString(engine.context()));
-        }
-        catch (InterruptedException _e) {  return; }
+    catch (EngineException e) { Values.printError(e, ""); }
+    catch (SyntaxException ex) {
+        System.out.println("Syntax error:" + ex.msg);
     }
-    catch (IOException | InterruptedException e) { return; }
+    catch (IOException e) { }
 }
 ```

build.js

@@ -1,7 +1,7 @@
 const { spawn } = require('child_process');
 const fs = require('fs/promises');
 const pt = require('path');
-const { argv } = require('process');
+const { argv, exit } = require('process');
 
 const conf = {
     name: "java-jscript",
@@ -74,6 +74,7 @@ async function compileJava() {
     }
     catch (e) {
         if (argv[2] === 'debug') throw e;
-        else console.log(e.toString());
+        console.log(e.toString());
+        exit(-1);
     }
 })();

src/me/topchetoeu/jscript/Filename.java

@@ -51,4 +51,10 @@ public class Filename {
         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());
+    }
 }

src/me/topchetoeu/jscript/Main.java

@@ -8,26 +8,21 @@ 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.StackData;
 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.events.Observer;
 import me.topchetoeu.jscript.exceptions.EngineException;
 import me.topchetoeu.jscript.exceptions.InterruptException;
 import me.topchetoeu.jscript.exceptions.SyntaxException;
+import me.topchetoeu.jscript.filesystem.MemoryFilesystem;
+import me.topchetoeu.jscript.filesystem.Mode;
+import me.topchetoeu.jscript.filesystem.PhysicalFilesystem;
 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 class Main {   
+    public static class Printer implements Observer<Object> {
         public void next(Object data) {
             Values.printValue(null, data);
             System.out.println();
@@ -37,115 +32,132 @@ public class Main {
             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(true);
+    static Thread engineTask, debugTask;
+    static Engine engine = new Engine(true);
+    static DebugServer debugServer = new DebugServer();
+    static Environment environment = new Environment(null, null, null);
 
-        env = new Environment(null, null, null);
-        var exited = new boolean[1];
-        var server = new DebugServer();
-        server.targets.put("target", (ws, req) -> new SimpleDebugger(ws, engine));
-
-        engineTask = engine.start();
-        debugTask = server.start(new InetSocketAddress("127.0.0.1", 9229), true);
-
-        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");
-                }
-            });
-            // TODO: make better API
-            env.global.define(true, new NativeFunction("include", (_ctx, th, __args) -> {
-                try {
-                    var currFilename = StackData.peekFrame(_ctx).function.loc().filename();
-                    var loc = Path.of("").toAbsolutePath();
-                    if (currFilename.protocol.equals("file")) loc = Path.of(currFilename.path).getParent();
-                    var path = loc.resolve(Path.of(__args.length >= 1 ? Values.toString(_ctx, __args[0]) : ""));
-                    var src = Files.readString(path);
-                    var func = _ctx.compile(Filename.fromFile(path.toFile()), src);
-                    var callArgs = new ArrayValue();
-                    if (__args.length >= 2 && __args[1] instanceof ArrayValue) callArgs = (ArrayValue)__args[1];
-                    return func.call(_ctx, null, callArgs);
-                }
-                catch (IOException e) { throw EngineException.ofError("IOError", "Couldn't open file."); }
-            }));
-
-            return null;
-        }), null).await();
+    static int j = 0;
+    static boolean exited = false;
+    static String[] args;
 
+    private static void reader() {
         try {
-            var tsEnv = env.child();
-            tsEnv.global.define(null, "module", false, new ObjectValue());
+            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, new Context(engine, 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.read();
+
+                    if (raw == null) break;
+                    var res = engine.pushMsg(
+                        false, new Context(engine, 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("exit", _ctx -> {
+            exited = true;
+            throw new InterruptException();
+        });
+        environment.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");
+            }
+        });
+
+        environment.filesystem.protocols.put("temp", new MemoryFilesystem(Mode.READ_WRITE));
+        environment.filesystem.protocols.put("file", new PhysicalFilesystem(Path.of(".").toAbsolutePath()));
+    }
+    private static void initEngine() {
+        debugServer.targets.put("target", (ws, req) -> new SimpleDebugger(ws, engine));
+        engineTask = engine.start();
+        debugTask = debugServer.start(new InetSocketAddress("127.0.0.1", 9229), true);
+    }
+    private static void initTypescript() {
+        try {
+            var tsEnv = Internals.apply(new Environment(null, null, null));
+            var bsEnv = Internals.apply(new Environment(null, null, null));
+
             engine.pushMsg(
-                false, new Context(engine).pushEnv(tsEnv),
+                false, new Context(engine, tsEnv),
                 new Filename("jscript", "ts.js"),
                 Reading.resourceToString("js/ts.js"), null
             ).await();
             System.out.println("Loaded typescript!");
 
-            var ctx = new Context(engine).pushEnv(env.child());
+            var ctx = new Context(engine, bsEnv);
 
             engine.pushMsg(
                 false, ctx,
                 new Filename("jscript", "internals/bootstrap.js"), Reading.resourceToString("js/bootstrap.js"), null,
-                tsEnv.global.get(ctx, "ts"), env, new ArrayValue(null, Reading.resourceToString("js/lib.d.ts"))
+                tsEnv.global.get(ctx, "ts"), environment, new ArrayValue(null, Reading.resourceToString("js/lib.d.ts"))
             ).await();
         }
         catch (EngineException e) {
             Values.printError(e, "(while initializing TS)");
         }
+    }
 
-        var reader = new Thread(() -> {
-            try {
-                for (var arg : args) {
-                    try {
-                        var file = Path.of(arg);
-                        var raw = Files.readString(file);
-                        valuePrinter.next(engine.pushMsg(false, new Context(engine).pushEnv(env), Filename.fromFile(file.toFile()), raw, null).await());
-                    }
-                    catch (EngineException e) { Values.printError(e, ""); }
-                }
-                for (var i = 0; ; i++) {
-                    try {
-                        var raw = Reading.read();
+    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();
 
-                        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) { exited[0] = true; }
-            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();
-                }
-            }
-            if (exited[0]) debugTask.interrupt();
-        });
         reader.setDaemon(true);
         reader.setName("STD Reader");
         reader.start();

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/compilation/CompoundStatement.java

@@ -24,9 +24,7 @@ public class CompoundStatement extends Statement {
     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());
             }
         }

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

@@ -33,8 +33,8 @@ public class SwitchStatement extends Statement {
 
     @Override
     public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
-        var caseMap = new HashMap<Integer, Integer>();
-        var stmIndexMap = new HashMap<Integer, Integer>();
+        var caseToStatement = new HashMap<Integer, Integer>();
+        var statementToIndex = new HashMap<Integer, Integer>();
 
         value.compile(target, scope, true);
 
@@ -42,7 +42,7 @@ public class SwitchStatement extends Statement {
             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);
+            caseToStatement.put(target.size(), ccase.statementI);
             target.add(Instruction.nop().locate(ccase.value.loc()));
         }
 
@@ -51,28 +51,31 @@ public class SwitchStatement extends Statement {
         target.add(Instruction.nop());
 
         for (var stm : body) {
-            stmIndexMap.put(stmIndexMap.size(), target.size());
+            statementToIndex.put(statementToIndex.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());
+        int end = target.size();
+        target.add(Instruction.discard().locate(loc()));
+        if (pollute) target.add(Instruction.loadValue(null));
 
-        for (int i = start; i < target.size(); i++) {
+        if (defaultI < 0 || defaultI >= body.length) target.set(start, Instruction.jmp(end - start).locate(loc()));
+        else target.set(start, Instruction.jmp(statementToIndex.get(defaultI) - start)).locate(loc());
+
+        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(target.size() - i).locate(instr.location));
+                target.set(i, Instruction.jmp(end - i).locate(instr.location));
             }
         }
-        for (var el : caseMap.entrySet()) {
+        for (var el : caseToStatement.entrySet()) {
             var loc = target.get(el.getKey()).location;
-            var i = stmIndexMap.get(el.getValue());
-            if (i == null) i = target.size();
+            var i = statementToIndex.get(el.getValue());
+            if (i == null) i = end;
             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) {

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

@@ -13,7 +13,7 @@ public class CommaStatement extends Statement {
     @Override
     public void compile(CompileTarget target, ScopeRecord scope, boolean pollute) {
         for (var i = 0; i < values.length; i++) {
-            values[i].compile(target, scope, i == values.length - 1 && pollute);
+            values[i].compileWithDebug(target, scope, i == values.length - 1 && pollute);
         }
     }
     

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

@@ -1,18 +1,23 @@
 package me.topchetoeu.jscript.engine;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 import java.util.Stack;
 import java.util.TreeSet;
 
 import me.topchetoeu.jscript.Filename;
 import me.topchetoeu.jscript.Location;
+import me.topchetoeu.jscript.engine.frame.CodeFrame;
 import me.topchetoeu.jscript.engine.values.FunctionValue;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
 import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.exceptions.EngineException;
 import me.topchetoeu.jscript.parsing.Parsing;
 
 public class Context {
     private final Stack<Environment> env = new Stack<>();
-    public final Data data;
+    private final ArrayList<CodeFrame> frames = new ArrayList<>();
     public final Engine engine;
 
     public Environment environment() {
@@ -28,7 +33,8 @@ public class Context {
     }
 
     public FunctionValue compile(Filename filename, String raw) {
-        var transpiled = environment().compile.call(this, null, raw, filename.toString());
+        var env = environment();
+        var transpiled = env.compile.call(this, null, raw, filename.toString(), env);
         String source = null;
         FunctionValue runner = null;
 
@@ -40,7 +46,7 @@ public class Context {
         else source = Values.toString(this, transpiled);
 
         var breakpoints = new TreeSet<Location>();
-        FunctionValue res = Parsing.compile(Engine.functions, breakpoints, environment(), filename, source);
+        FunctionValue res = Parsing.compile(Engine.functions, breakpoints, env, filename, source);
         engine.onSource(filename, source, breakpoints);
 
         if (runner != null) res = (FunctionValue)runner.call(this, null, res);
@@ -48,12 +54,58 @@ public class Context {
         return res;
     }
 
-    public Context(Engine engine, Data data) {
-        this.data = new Data(engine.data);
-        if (data != null) this.data.addAll(data);
+
+    public void pushFrame(CodeFrame frame) {
+        frames.add(frame);
+        if (frames.size() > engine.maxStackFrames) throw EngineException.ofRange("Stack overflow!");
+        pushEnv(frame.function.environment);
+    }
+    public boolean popFrame(CodeFrame frame) {
+        if (frames.size() == 0) return false;
+        if (frames.get(frames.size() - 1) != frame) return false;
+        frames.remove(frames.size() - 1);
+        popEnv();
+        engine.onFramePop(this, frame);
+        return true;
+    }
+    public CodeFrame peekFrame() {
+        if (frames.size() == 0) return null;
+        return frames.get(frames.size() - 1);
+    }
+
+    public List<CodeFrame> frames() {
+        return Collections.unmodifiableList(frames);
+    }
+    public List<String> stackTrace() {
+        var res = new ArrayList<String>();
+
+        for (var i = frames.size() - 1; i >= 0; i--) {
+            var el = frames.get(i);
+            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;
+    }
+
+    public Context(Engine engine) {
         this.engine = engine;
     }
-    public Context(Engine engine) {
-        this(engine, null);
+    public Context(Engine engine, Environment env) {
+        this(engine);
+        this.pushEnv(env);
+        
     }
 }

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

@@ -5,7 +5,6 @@ import java.util.Map;
 
 @SuppressWarnings("unchecked")
 public class Data {
-    public final Data parent;
     private HashMap<DataKey<Object>, Object> data = new HashMap<>();
 
     public Data copy() {
@@ -33,19 +32,12 @@ public class Data {
         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);
-            }
-        }
-
+        if (data.containsKey(key)) return (T)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);
-        }
+        if (data.containsKey(key)) return (T)data.get((DataKey<Object>)key);
         return null;
     }
     public boolean has(DataKey<?> key) { return data.containsKey(key); }
@@ -61,11 +53,4 @@ public class Data {
     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/Engine.java

@@ -2,7 +2,7 @@ package me.topchetoeu.jscript.engine;
 
 import java.util.HashMap;
 import java.util.TreeSet;
-import java.util.concurrent.LinkedBlockingDeque;
+import java.util.concurrent.PriorityBlockingQueue;
 
 import me.topchetoeu.jscript.Filename;
 import me.topchetoeu.jscript.Location;
@@ -35,34 +35,41 @@ public class Engine implements DebugController {
         }
     }
 
-    private static class Task {
+    private static class Task implements Comparable<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 final boolean micro;
 
-        public Task(Context ctx, FunctionValue func, Object thisArg, Object[] args) {
+        public Task(Context ctx, FunctionValue func, Object thisArg, Object[] args, boolean micro) {
             this.ctx = ctx;
             this.func = func;
             this.thisArg = thisArg;
             this.args = args;
+            this.micro = micro;
+        }
+
+        @Override
+        public int compareTo(Task other) {
+            return Integer.compare(this.micro ? 0 : 1, other.micro ? 0 : 1);
         }
     }
 
     private static int nextId = 0;
     public static final HashMap<Long, FunctionBody> functions = new HashMap<>();
 
-    private Thread thread;
-    private LinkedBlockingDeque<Task> macroTasks = new LinkedBlockingDeque<>();
-    private LinkedBlockingDeque<Task> microTasks = new LinkedBlockingDeque<>();
-
     public final int id = ++nextId;
-    public final Data data = new Data().set(StackData.MAX_FRAMES, 200);
     public final boolean debugging;
+    public int maxStackFrames = 10000;
+
     private final HashMap<Filename, String> sources = new HashMap<>();
     private final HashMap<Filename, TreeSet<Location>> bpts = new HashMap<>();
+
     private DebugController debugger;
+    private Thread thread;
+    private PriorityBlockingQueue<Task> tasks = new PriorityBlockingQueue<>();
 
     public boolean attachDebugger(DebugController debugger) {
         if (!debugging || this.debugger != null) return false;
@@ -80,20 +87,6 @@ public class Engine implements DebugController {
         return true;
     }
 
-    @Override public void onFramePop(Context ctx, CodeFrame frame) {
-        if (debugging && debugger != null) debugger.onFramePop(ctx, frame);
-    }
-    @Override public boolean onInstruction(Context ctx, CodeFrame frame, Instruction instruction, Object returnVal, EngineException error, boolean caught) {
-        if (debugging && 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) {
-        if (!debugging) return;
-        if (debugger != null) debugger.onSource(filename, source, breakpoints);
-        sources.put(filename, source);
-        bpts.put(filename, breakpoints);
-    }
-
     private void runTask(Task task) {
         try {
             task.notifier.next(task.func.call(task.ctx, task.thisArg, task.args));
@@ -104,18 +97,12 @@ public class Engine implements DebugController {
         }
     }
     public void run(boolean untilEmpty) {
-        while (!untilEmpty || !macroTasks.isEmpty()) {
+        while (!untilEmpty || !tasks.isEmpty()) {
             try {
-                runTask(macroTasks.take());
-
-                while (!microTasks.isEmpty()) {
-                    runTask(microTasks.take());
-                }
+                runTask(tasks.take());
             }
             catch (InterruptedException | InterruptException e) {
-                for (var msg : macroTasks) {
-                    msg.notifier.error(new InterruptException(e));
-                }
+                for (var msg : tasks) msg.notifier.error(new InterruptException(e));
                 break;
             }
         }
@@ -140,15 +127,28 @@ public class Engine implements DebugController {
     }
 
     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);
+        var msg = new Task(ctx == null ? new Context(this) : ctx, func, thisArg, args, micro);
+        tasks.add(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);
     }
 
+    @Override public void onFramePop(Context ctx, CodeFrame frame) {
+        if (debugging && debugger != null) debugger.onFramePop(ctx, frame);
+    }
+    @Override public boolean onInstruction(Context ctx, CodeFrame frame, Instruction instruction, Object returnVal, EngineException error, boolean caught) {
+        if (debugging && 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) {
+        if (!debugging) return;
+        if (debugger != null) debugger.onSource(filename, source, breakpoints);
+        sources.put(filename, source);
+        bpts.put(filename, breakpoints);
+    }
+
     public Engine(boolean debugging) {
         this.debugging = debugging;
     }

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

@@ -8,12 +8,15 @@ 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.exceptions.EngineException;
+import me.topchetoeu.jscript.filesystem.RootFilesystem;
 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.permissions.Permission;
+import me.topchetoeu.jscript.permissions.PermissionsProvider;
 
-public class Environment {
+public class Environment implements PermissionsProvider {
     private HashMap<String, ObjectValue> prototypes = new HashMap<>();
 
     public final Data data = new Data();
@@ -21,6 +24,12 @@ public class Environment {
 
     public GlobalScope global;
     public WrappersProvider wrappers;
+    public PermissionsProvider permissions = null;
+    public final RootFilesystem filesystem = new RootFilesystem(this);
+
+    private static int nextId = 0;
+
+    @Native public int id = ++nextId;
 
     @Native public FunctionValue compile;
     @Native public FunctionValue regexConstructor = new NativeFunction("RegExp", (ctx, thisArg, args) -> {
@@ -68,9 +77,13 @@ public class Environment {
         return res;
     }
 
-    public Context context(Engine engine, Data data) {
-        return new Context(engine, data).pushEnv(this);
+    @Override public boolean hasPermission(Permission perm, char delim) {
+        return permissions == null || permissions.hasPermission(perm, delim);
     }
+    @Override public boolean hasPermission(Permission perm) {
+        return permissions == null || permissions.hasPermission(perm);
+    }
+
     public Context context(Engine engine) {
         return new Context(engine).pushEnv(this);
     }

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.Location;
-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();
-        ctx.engine.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;
-            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;
-    }
-}

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

@@ -19,7 +19,7 @@ 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<>();
 
@@ -236,9 +236,9 @@ public class DebugServer {
             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("${AUTHOR}", Metadata.AUTHOR)
+                .replace("${NAME}", Metadata.name())
+                .replace("${VERSION}", Metadata.version())
+                .replace("${AUTHOR}", Metadata.author())
                 .getBytes();
         }
         catch (IOException e) { throw new UncheckedIOException(e); }

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

@@ -15,7 +15,6 @@ import me.topchetoeu.jscript.compilation.Instruction;
 import me.topchetoeu.jscript.compilation.Instruction.Type;
 import me.topchetoeu.jscript.engine.Context;
 import me.topchetoeu.jscript.engine.Engine;
-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.GlobalScope;
@@ -32,6 +31,7 @@ import me.topchetoeu.jscript.json.JSONElement;
 import me.topchetoeu.jscript.json.JSONList;
 import me.topchetoeu.jscript.json.JSONMap;
 
+// very simple indeed
 public class SimpleDebugger implements Debugger {
     public static final String CHROME_GET_PROP_FUNC = "function s(e){let t=this;const n=JSON.parse(e);for(let e=0,i=n.length;e<i;++e)t=t[n[e]];return t}";
     public static final String VSCODE_STRINGIFY_VAL = "function(...runtimeArgs){\n    let t = 1024; let e = null;\n    if(e)try{let r=\"<<default preview>>\",i=e.call(this,r);if(i!==r)return String(i)}catch(r){return`<<indescribable>>${JSON.stringify([String(r),\"object\"])}`}if(typeof this==\"object\"&&this){let r;for(let i of[Symbol.for(\"debug.description\"),Symbol.for(\"nodejs.util.inspect.custom\")])try{r=this[i]();break}catch{}if(!r&&!String(this.toString).includes(\"[native code]\")&&(r=String(this)),r&&!r.startsWith(\"[object \"))return r.length>=t?r.slice(0,t)+\"\\u2026\":r}\n  ;\n\n}";
@@ -112,7 +112,6 @@ public class SimpleDebugger implements Debugger {
             this.frame = frame;
             this.func = frame.function;
             this.id = id;
-            this.local = new ObjectValue();
             this.location = frame.function.loc();
 
             this.global = frame.function.environment.global.obj;
@@ -138,7 +137,7 @@ public class SimpleDebugger implements Debugger {
         }
     }
 
-    private class RunResult {
+    private static class RunResult {
         public final Context ctx;
         public final Object result;
         public final EngineException error;
@@ -188,7 +187,7 @@ public class SimpleDebugger implements Debugger {
     }
 
     private void updateFrames(Context ctx) {
-        var frame = StackData.peekFrame(ctx);
+        var frame = ctx.peekFrame();
         if (frame == null) return;
 
         if (!codeFrameToFrame.containsKey(frame)) {
@@ -203,7 +202,7 @@ public class SimpleDebugger implements Debugger {
     }
     private JSONList serializeFrames(Context ctx) {
         var res = new JSONList();
-        var frames = StackData.frames(ctx);
+        var frames = ctx.frames();
 
         for (var i = frames.size() - 1; i >= 0; i--) {
             res.add(codeFrameToFrame.get(frames.get(i)).serialized);
@@ -475,8 +474,9 @@ public class SimpleDebugger implements Debugger {
     @Override public void setBreakpointByUrl(V8Message msg) {
         var line = (int)msg.params.number("lineNumber") + 1;
         var col = (int)msg.params.number("columnNumber", 0) + 1;
-        var cond = msg.params.string("condition", null);
+        var cond = msg.params.string("condition", "").trim();
 
+        if (cond.equals("")) cond = null;
         if (cond != null) cond  = "(" + cond + ")";
 
         Pattern regex;
@@ -600,10 +600,10 @@ public class SimpleDebugger implements Debugger {
         if (obj != emptyObject) {
             for (var key : obj.keys(true)) {
                 var propDesc = new JSONMap();
-    
+
                 if (obj.properties.containsKey(key)) {
                     var prop = obj.properties.get(key);
-    
+
                     propDesc.set("name", Values.toString(ctx, key));
                     if (prop.getter != null) propDesc.set("get", serializeObj(ctx, prop.getter));
                     if (prop.setter != null) propDesc.set("set", serializeObj(ctx, prop.setter));
@@ -783,7 +783,7 @@ public class SimpleDebugger implements Debugger {
         try { idToFrame.remove(codeFrameToFrame.remove(frame).id); }
         catch (NullPointerException e) { }
 
-        if (StackData.frames(ctx).size() == 0) resume(State.RESUMED);
+        if (ctx.frames().size() == 0) resume(State.RESUMED);
         else if (stepOutFrame != null && stepOutFrame.frame == frame &&
             (state == State.STEPPING_OUT || state == State.STEPPING_IN || state == State.STEPPING_OVER)
         ) {

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

@@ -118,8 +118,6 @@ public class WebSocket implements AutoCloseable {
         else send(msg.textData());
     }
     public void send(Object data) {
-        // TODO: Remove
-        // System.out.println("SEND: " + data);
         if (closed) throw new IllegalStateException("Object is closed.");
         write(1, data.toString().getBytes());
     }
@@ -201,10 +199,6 @@ public class WebSocket implements AutoCloseable {
                 if (!fin) continue;
                 var raw = data.toByteArray();
 
-                // TODO: Remove
-                // System.out.println("RECEIVED: " + new String(raw));
-
-
                 if (type == 1) return new WebSocketMessage(new String(raw));
                 else return new WebSocketMessage(raw);
             }

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

@@ -4,6 +4,7 @@ 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.scope.LocalScope;
 import me.topchetoeu.jscript.engine.scope.ValueVariable;
@@ -151,15 +152,17 @@ public class CodeFrame {
     public Object next(Context ctx, Object value, Object returnValue, EngineException error) {
         if (value != Runners.NO_RETURN) push(ctx, value);
 
+        Instruction instr = null;
+        if (codePtr >= 0 && codePtr < function.body.length) instr = function.body[codePtr];
+
         if (returnValue == Runners.NO_RETURN && error == null) {
             try {
                 if (Thread.currentThread().isInterrupted()) throw new InterruptException();
 
-                var instr = function.body[codePtr];
-                ctx.engine.onInstruction(ctx, this, instr, Runners.NO_RETURN, null, false);
-
-                if (codePtr < 0 || codePtr >= function.body.length) returnValue = null;
+                if (instr == null) returnValue = null;
                 else {
+                    ctx.engine.onInstruction(ctx, this, instr, Runners.NO_RETURN, null, false);
+
                     if (instr.location != null) prevLoc = instr.location;
 
                     try {
@@ -278,11 +281,11 @@ public class CodeFrame {
         }
 
         if (error != null) {
-            ctx.engine.onInstruction(ctx, this, function.body[codePtr], null, error, false);
+            ctx.engine.onInstruction(ctx, this, instr, null, error, false);
             throw error;
         }
         if (returnValue != Runners.NO_RETURN) {
-            ctx.engine.onInstruction(ctx, this, function.body[codePtr], returnValue, null, false);
+            ctx.engine.onInstruction(ctx, this, instr, returnValue, null, false);
             return returnValue;
         }
 

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

@@ -5,7 +5,6 @@ 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;
@@ -35,7 +34,7 @@ public class CodeFunction extends FunctionValue {
     public Object call(Context ctx, Object thisArg, Object ...args) {
         var frame = new CodeFrame(ctx, thisArg, args, this);
         try {
-            StackData.pushFrame(ctx, frame);
+            ctx.pushFrame(frame);
 
             while (true) {
                 var res = frame.next(ctx, Runners.NO_RETURN, Runners.NO_RETURN, null);
@@ -43,7 +42,7 @@ public class CodeFunction extends FunctionValue {
             }
         }
         finally {
-            StackData.popFrame(ctx, frame);
+            ctx.popFrame(frame);
         }
     }
 

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

@@ -11,7 +11,7 @@ public abstract class FunctionValue extends ObjectValue {
 
     @Override
     public String toString() {
-        return "function(...) {  ...}";
+        return String.format("function %s(...)", name);
     }
 
     public abstract Object call(Context ctx, Object thisArg, Object ...args);
@@ -21,21 +21,21 @@ public abstract class FunctionValue extends ObjectValue {
 
     @Override
     protected Object getField(Context ctx, Object key) {
-        if (key.equals("name")) return name;
-        if (key.equals("length")) return length;
+        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 (key.equals("name")) name = Values.toString(ctx, val);
-        else if (key.equals("length")) length = (int)Values.toNumber(ctx, 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 (key.equals("name")) return true;
-        if (key.equals("length")) return true;
+        if ("name".equals(key)) return true;
+        if ("length".equals(key)) return true;
         return super.hasField(ctx, key);
     }
 

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

@@ -12,6 +12,19 @@ public class NativeWrapper extends ObjectValue {
         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

@@ -262,7 +262,7 @@ public class ObjectValue {
             values.put(key, val);
             return true;
         }
-        else if (key.equals("__proto__")) return setPrototype(ctx, val);
+        else if ("__proto__".equals(key)) return setPrototype(ctx, val);
         else if (nonWritableSet.contains(key)) return false;
         else return setField(ctx, key, val);
     }
@@ -273,7 +273,7 @@ public class ObjectValue {
     public final boolean hasMember(Context ctx, Object key, boolean own) {
         key = Values.normalize(ctx, key);
 
-        if (key != null && key.equals("__proto__")) return true;
+        if (key != null && "__proto__".equals(key)) return true;
         if (hasField(ctx, key)) return true;
         if (properties.containsKey(key)) return true;
         if (own) return false;

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

@@ -17,8 +17,27 @@ 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 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 boolean isObject(Object val) { return val instanceof ObjectValue; }
@@ -105,7 +124,7 @@ 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;
@@ -137,7 +156,7 @@ 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";
     }
@@ -191,12 +210,18 @@ 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) {
@@ -232,10 +257,10 @@ 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]);
@@ -272,15 +297,20 @@ 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 (key != null && "__proto__".equals(key)) return setPrototype(ctx, obj, val);
         if (isObject(obj)) return object(obj).setMember(ctx, key, val, false);
 
         var proto = getPrototype(ctx, obj);
@@ -290,7 +320,7 @@ 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 ("__proto__".equals(key)) return true;
         if (isObject(obj)) return object(obj).hasMember(ctx, key, own);
 
         if (obj instanceof String && key instanceof Number) {
@@ -518,7 +548,7 @@ public class Values {
         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");
@@ -571,7 +601,7 @@ public class Values {
         };
     }
 
-    public static ObjectValue fromJavaIterator(Context ctx, Iterator<?> it) {
+    public static ObjectValue toJSIterator(Context ctx, Iterator<?> it) {
         var res = new ObjectValue();
 
         try {
@@ -592,10 +622,43 @@ public class Values {
         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.environment().proto("symbol"), "constructor", "asyncIterator");
+            res.defineProperty(ctx, key, new NativeFunction("", (_ctx, thisArg, args) -> thisArg));
+        }
+        catch (IllegalArgumentException | NullPointerException e) { }
+
+        res.defineProperty(ctx, "next", new NativeFunction("", (_ctx, _th, _args) -> {
+            return PromiseLib.await(ctx, () -> {
+                if (!it.hasNext()) return new ObjectValue(ctx, Map.of("done", true));
+                else {
+                    var obj = new ObjectValue();
+                    obj.defineProperty(_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);
@@ -610,10 +673,7 @@ 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);
@@ -643,7 +703,7 @@ 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 {
@@ -661,12 +721,13 @@ 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");

src/me/topchetoeu/jscript/filesystem/Buffer.java

@@ -0,0 +1,41 @@
+package me.topchetoeu.jscript.filesystem;
+
+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 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);
+    }
+}

src/me/topchetoeu/jscript/filesystem/EntryType.java

@@ -1,7 +1,13 @@
 package me.topchetoeu.jscript.filesystem;
 
 public enum EntryType {
-    NONE,
-    FILE,
-    FOLDER,
+    NONE("none"),
+    FILE("file"),
+    FOLDER("folder");
+
+    public final String name;
+
+    private EntryType(String name) {
+        this.name = name;
+    }
 }

src/me/topchetoeu/jscript/filesystem/File.java

@@ -1,27 +1,39 @@
 package me.topchetoeu.jscript.filesystem;
 
-import java.io.IOException;
-
 public interface File {
-    int read() throws IOException, InterruptedException;
-    boolean write(byte val) throws IOException, InterruptedException;
-    long tell() throws IOException, InterruptedException;
-    void seek(long offset, int pos) throws IOException, InterruptedException;
-    void close() throws IOException, InterruptedException;
-    Permissions perms();
+    int read(byte[] buff);
+    void write(byte[] buff);
+    long getPtr();
+    void setPtr(long offset, int pos);
+    void close();
+    Mode mode();
 
-    default String readToString() throws IOException, InterruptedException {
-        seek(0, 2);
-        long len = tell();
+    default String readToString() {
+        setPtr(0, 2);
+        long len = getPtr();
         if (len < 0) return null;
 
-        seek(0, 0);
-        byte[] res = new byte[(int)len];
+        setPtr(0, 0);
 
-        for (var i = 0; i < len; i++) {
-            res[i] = (byte)read();
-        }
+        byte[] res = new byte[(int)len];
+        read(res);
 
         return new String(res);
     }
+    default String readLine() {
+        var res = new Buffer(new byte[0]);
+        var buff = new byte[1];
+
+        while (true) {
+            if (read(buff) == 0) {
+                if (res.length() == 0) return null;
+                else break;
+            }
+
+            if (buff[0] == '\n') break;
+
+            res.write(res.length(), buff);
+        }
+        return new String(res.data());
+    }
 }

src/me/topchetoeu/jscript/filesystem/FileStat.java

@@ -0,0 +1,11 @@
+package me.topchetoeu.jscript.filesystem;
+
+public class FileStat {
+    public final Mode mode;
+    public final EntryType type;
+
+    public FileStat(Mode mode, EntryType type) {
+        this.mode = mode;
+        this.type = type;
+    }
+}

src/me/topchetoeu/jscript/filesystem/Filesystem.java

@@ -1,10 +1,7 @@
 package me.topchetoeu.jscript.filesystem;
 
-import java.io.IOException;
-
 public interface Filesystem {
-    File open(String path) throws IOException, InterruptedException;
-    boolean mkdir(String path) throws IOException, InterruptedException;
-    EntryType type(String path) throws IOException, InterruptedException;
-    boolean rm(String path) throws IOException, InterruptedException;
-}
+    File open(String path, Mode mode) throws FilesystemException;
+    void create(String path, EntryType type) throws FilesystemException;
+    FileStat stat(String path) throws FilesystemException;
+}

src/me/topchetoeu/jscript/filesystem/FilesystemException.java

@@ -0,0 +1,55 @@
+package me.topchetoeu.jscript.filesystem;
+
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.exceptions.EngineException;
+
+public class FilesystemException extends RuntimeException {
+    public static enum FSCode {
+        DOESNT_EXIST(0x1),
+        NOT_FILE(0x2),
+        NOT_FOLDER(0x3),
+        NO_PERMISSIONS_R(0x4),
+        NO_PERMISSIONS_RW(0x5),
+        FOLDER_NOT_EMPTY(0x6),
+        ALREADY_EXISTS(0x7),
+        FOLDER_EXISTS(0x8);
+
+        public final int code;
+
+        private FSCode(int code) { this.code = code; }
+    }
+
+    public static final String[] MESSAGES = {
+        "How did we get here?",
+        "The file or folder '%s' doesn't exist or is inaccessible.",
+        "'%s' is not a file",
+        "'%s' is not a folder",
+        "No permissions to read '%s'",
+        "No permissions to write '%s'",
+        "Can't delete '%s', since it is a full folder.",
+        "'%s' already exists."
+    };
+
+    public final String message, filename;
+    public final FSCode code;
+
+    public FilesystemException(String message, String filename, FSCode code) {
+        super(code + ": " + String.format(message, filename));
+        this.message = message;
+        this.code = code;
+        this.filename = filename;
+    }
+    public FilesystemException(String filename, FSCode code) {
+        super(code + ": " + String.format(MESSAGES[code.code], filename));
+        this.message = MESSAGES[code.code];
+        this.code = code;
+        this.filename = filename;
+    }
+
+    public EngineException toEngineException() {
+        var res = EngineException.ofError("IOError", getMessage());
+        Values.setMember(null, res.value, "code", code);
+        Values.setMember(null, res.value, "filename", filename.toString());
+        return res;
+    }
+}

src/me/topchetoeu/jscript/filesystem/InaccessibleFile.java

@@ -1,35 +0,0 @@
-package me.topchetoeu.jscript.filesystem;
-
-import java.io.IOException;
-
-public class InaccessibleFile implements File {
-    public static final InaccessibleFile INSTANCE = new InaccessibleFile();
-
-    @Override
-    public int read() throws IOException, InterruptedException {
-        return -1;
-    }
-
-    @Override
-    public boolean write(byte val) throws IOException, InterruptedException {
-        return false;
-    }
-
-    @Override
-    public long tell() throws IOException, InterruptedException {
-        return 0;
-    }
-
-    @Override
-    public void seek(long offset, int pos) throws IOException, InterruptedException { }
-
-    @Override
-    public void close() throws IOException, InterruptedException { }
-
-    @Override
-    public Permissions perms() {
-        return Permissions.NONE;
-    }
-
-    private InaccessibleFile() { }
-}

src/me/topchetoeu/jscript/filesystem/MemoryFile.java

@@ -1,53 +1,66 @@
 package me.topchetoeu.jscript.filesystem;
 
-import java.io.IOException;
+import me.topchetoeu.jscript.filesystem.FilesystemException.FSCode;
 
 public class MemoryFile implements File {
     private int ptr;
-    private Permissions mode;
-    public final byte[] data;
+    private Mode mode;
+    private Buffer data;
+    private String filename;
+
+    public Buffer data() { return data; }
 
     @Override
-    public int read() throws IOException, InterruptedException {
-        if (data == null || !mode.readable || ptr >= data.length) return -1;
-        return data[ptr++];
+    public int read(byte[] buff) {
+        if (data == null || !mode.readable) throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R);
+        var res = data.read(ptr, buff);
+        ptr += res;
+        return res;
+    }
+    @Override
+    public void write(byte[] buff) {
+        if (data == null || !mode.writable) throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_RW);
+
+        data.write(ptr, buff);
+        ptr += buff.length;
     }
 
     @Override
-    public boolean write(byte val) throws IOException, InterruptedException {
-        if (data == null || !mode.writable || ptr >= data.length) return false;
-        data[ptr++] = val;
-        return true;
-    }
-
-    @Override
-    public long tell() throws IOException, InterruptedException {
+    public long getPtr() {
+        if (data == null || !mode.readable) throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R);
         return ptr;
     }
-
     @Override
-    public void seek(long offset, int pos) throws IOException, InterruptedException {
-        if (data == null) return;
+    public void setPtr(long offset, int pos) {
+        if (data == null || !mode.readable) throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R);
 
         if (pos == 0) ptr = (int)offset;
         else if (pos == 1) ptr += (int)offset;
-        else if (pos == 2) ptr = data.length - (int)offset;
+        else if (pos == 2) ptr = data.length() - (int)offset;
     }
 
     @Override
-    public void close() throws IOException, InterruptedException {
-        mode = null;
+    public void close() {
+        mode = Mode.NONE;
         ptr = 0;
     }
-
     @Override
-    public Permissions perms() {
-        if (data == null) return Permissions.NONE;
+    public Mode mode() {
+        if (data == null) return Mode.NONE;
         return mode;
     }
 
-    public MemoryFile(byte[] buff, Permissions mode) {
+    public MemoryFile(String filename, Buffer buff, Mode mode) {
+        this.filename = filename;
         this.data = buff;
         this.mode = mode;
     }
+
+    public static MemoryFile fromFileList(String filename, java.io.File[] list) {
+        var res = new StringBuilder();
+
+        for (var el : list) res.append(el.getName()).append('\n');
+
+        return new MemoryFile(filename, new Buffer(res.toString().getBytes()), Mode.READ);
+    }
 }

src/me/topchetoeu/jscript/filesystem/MemoryFilesystem.java

@@ -0,0 +1,89 @@
+package me.topchetoeu.jscript.filesystem;
+
+import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.HashSet;
+
+import me.topchetoeu.jscript.filesystem.FilesystemException.FSCode;
+
+public class MemoryFilesystem implements Filesystem {
+    public final Mode mode;
+    private HashMap<Path, Buffer> files = new HashMap<>();
+    private HashSet<Path> folders = new HashSet<>();
+
+    private Path getPath(String name) {
+        return Path.of("/" + name.replace("\\", "/")).normalize();
+    }
+
+    @Override
+    public void create(String path, EntryType type) {
+        var _path = getPath(path);
+
+        switch (type) {
+            case FILE:
+                if (!folders.contains(_path.getParent())) throw new FilesystemException(path, FSCode.DOESNT_EXIST);
+                if (folders.contains(_path) || files.containsKey(_path)) throw new FilesystemException(path, FSCode.ALREADY_EXISTS);
+                if (folders.contains(_path)) throw new FilesystemException(path, FSCode.ALREADY_EXISTS);
+                files.put(_path, new Buffer(new byte[0]));
+                break;
+            case FOLDER:
+                if (!folders.contains(_path.getParent())) throw new FilesystemException(path, FSCode.DOESNT_EXIST);
+                if (folders.contains(_path) || files.containsKey(_path)) throw new FilesystemException(path, FSCode.ALREADY_EXISTS);
+                folders.add(_path);
+                break;
+            default:
+            case NONE:
+                if (!folders.remove(_path) && files.remove(_path) == null) throw new FilesystemException(path, FSCode.DOESNT_EXIST);
+        }
+    }
+
+    @Override
+    public File open(String path, Mode perms) {
+        var _path = getPath(path);
+        var pcount = _path.getNameCount();
+
+        if (files.containsKey(_path)) return new MemoryFile(path, files.get(_path), perms);
+        else if (folders.contains(_path)) {
+            var res = new StringBuilder();
+            for (var folder : folders) {
+                if (pcount + 1 != folder.getNameCount()) continue;
+                if (!folder.startsWith(_path)) continue;
+                res.append(folder.toFile().getName()).append('\n');
+            }
+            for (var file : files.keySet()) {
+                if (pcount + 1 != file.getNameCount()) continue;
+                if (!file.startsWith(_path)) continue;
+                res.append(file.toFile().getName()).append('\n');
+            }
+            return new MemoryFile(path, new Buffer(res.toString().getBytes()), perms.intersect(Mode.READ));
+        }
+        else throw new FilesystemException(path, FSCode.DOESNT_EXIST);
+    }
+
+    @Override
+    public FileStat stat(String path) {
+        var _path = getPath(path);
+
+        if (files.containsKey(_path)) return new FileStat(mode, EntryType.FILE);
+        else if (folders.contains(_path)) return new FileStat(mode, EntryType.FOLDER);
+        else throw new FilesystemException(path, FSCode.DOESNT_EXIST);
+    }
+
+    public MemoryFilesystem put(String path, byte[] data) {
+        var _path = getPath(path);
+        var _curr = "/";
+
+        for (var seg : _path) {
+            create(_curr, EntryType.FOLDER);
+            _curr += seg + "/";
+        }
+
+        files.put(_path, new Buffer(data));
+        return this;
+    }
+
+    public MemoryFilesystem(Mode mode) {
+        this.mode = mode;
+        folders.add(Path.of("/"));
+    }
+}

src/me/topchetoeu/jscript/filesystem/Mode.java

@@ -0,0 +1,31 @@
+package me.topchetoeu.jscript.filesystem;
+
+public enum Mode {
+    NONE("", false, false),
+    READ("r", true, false),
+    READ_WRITE("rw", true, true);
+
+    public final String name;
+    public final boolean readable;
+    public final boolean writable;
+
+    public Mode intersect(Mode other) {
+        if (this == NONE || other == NONE) return NONE;
+        if (this == READ_WRITE && other == READ_WRITE) return READ_WRITE;
+        return READ;
+    }
+
+    private Mode(String mode, boolean r, boolean w) {
+        this.name = mode;
+        this.readable = r;
+        this.writable = w;
+    }
+
+    public static Mode parse(String mode) {
+        switch (mode) {
+            case "r": return READ;
+            case "rw": return READ_WRITE;
+            default: return NONE;
+        }
+    }
+}

src/me/topchetoeu/jscript/filesystem/Permissions.java

@@ -1,17 +0,0 @@
-package me.topchetoeu.jscript.filesystem;
-
-public enum Permissions {
-    NONE("", false, false),
-    READ("r", true, false),
-    READ_WRITE("rw", true, true);
-
-    public final String readMode;
-    public final boolean readable;
-    public final boolean writable;
-
-    private Permissions(String mode, boolean r, boolean w) {
-        this.readMode = mode;
-        this.readable = r;
-        this.writable = w;
-    }
-}

src/me/topchetoeu/jscript/filesystem/PhysicalFile.java

@@ -1,50 +1,62 @@
 package me.topchetoeu.jscript.filesystem;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.RandomAccessFile;
 
+import me.topchetoeu.jscript.filesystem.FilesystemException.FSCode;
+
 public class PhysicalFile implements File {
+    private String filename;
     private RandomAccessFile file;
-    private Permissions perms;
+    private Mode perms;
 
     @Override
-    public int read() throws IOException, InterruptedException {
-        if (file == null || !perms.readable) return -1;
-        else return file.read();
+    public int read(byte[] buff) {
+        if (file == null || !perms.readable) throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R);
+        else try { return file.read(buff); }
+        catch (IOException e) { throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R); }
+    }
+    @Override
+    public void write(byte[] buff) {
+        if (file == null || !perms.writable) throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_RW);
+        else try { file.write(buff); }
+        catch (IOException e) { throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_RW); }
     }
 
     @Override
-    public boolean write(byte val) throws IOException, InterruptedException {
-        if (file == null || !perms.writable) return false;
-        file.write(val);
-        return true;
+    public long getPtr() {
+        if (file == null || !perms.readable) throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R);
+        else try { return file.getFilePointer(); }
+        catch (IOException e) { throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R); }
+    }
+    @Override
+    public void setPtr(long offset, int pos) {
+        if (file == null || !perms.readable) throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R);
+
+        try {
+            if (pos == 1) pos += file.getFilePointer();
+            else if (pos == 2) pos += file.length();
+            file.seek(pos);
+        }
+        catch (IOException e) { throw new FilesystemException(filename, FSCode.NO_PERMISSIONS_R); }
     }
 
     @Override
-    public long tell() throws IOException, InterruptedException {
-        if (file == null) return 0;
-        return file.getFilePointer();
-    }
-    @Override
-    public void seek(long offset, int pos) throws IOException, InterruptedException {
+    public void close() {
         if (file == null) return;
-        if (pos == 0) file.seek(pos);
-        else if (pos == 1) file.seek(file.getFilePointer() + pos);
-        else if (pos == 2) file.seek(file.length() + pos);
+        try { file.close(); }
+        catch (IOException e) {} // SHUT
+        file = null;
+        perms = Mode.NONE;
     }
-
     @Override
-    public void close() throws IOException, InterruptedException {
-        if (file == null) return;
-        file.close();
-    }
+    public Mode mode() { return perms; }
 
-    @Override
-    public Permissions perms() { return perms; }
-    
-    public PhysicalFile(String path, Permissions mode) throws IOException {
-        if (mode == Permissions.NONE) file = null;
-        else file = new RandomAccessFile(path, mode.readMode);
+    public PhysicalFile(String path, Mode mode) throws FileNotFoundException {
+        if (mode == Mode.NONE) file = null;
+        else try { file = new RandomAccessFile(path, mode.name); }
+        catch (FileNotFoundException e) { throw new FilesystemException(filename, FSCode.DOESNT_EXIST); }
 
         perms = mode;
     }

src/me/topchetoeu/jscript/filesystem/PhysicalFilesystem.java

@@ -1,74 +1,74 @@
 package me.topchetoeu.jscript.filesystem;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.Path;
 
+import me.topchetoeu.jscript.filesystem.FilesystemException.FSCode;
+
 public class PhysicalFilesystem implements Filesystem {
     public final Path root;
 
-    private Permissions getPerms(Path path) {
-        var file = path.toFile();
-        if (!path.startsWith(root)) return Permissions.NONE;
-        if (file.canRead() && file.canWrite()) return Permissions.READ_WRITE;
-        if (file.canRead()) return Permissions.READ;
-
-        return Permissions.NONE;
-    }
     private Path getPath(String name) {
-        return root.resolve(name);
+        return root.resolve(name.replace("\\", "/")).normalize();
+    }
+
+    private void checkMode(Path path, Mode mode) {
+        if (!path.startsWith(root)) throw new FilesystemException(path.toString(), FSCode.NO_PERMISSIONS_R);
+        if (mode.readable && !path.toFile().canRead()) throw new FilesystemException(path.toString(), FSCode.NO_PERMISSIONS_R);
+        if (mode.writable && !path.toFile().canWrite()) throw new FilesystemException(path.toString(), FSCode.NO_PERMISSIONS_RW);
     }
 
     @Override
-    public File open(String path) throws IOException, InterruptedException {
-        var _path = root.resolve(path);
-
-        var perms = getPerms(_path);
-        if (perms == Permissions.NONE) return InaccessibleFile.INSTANCE;
-
+    public File open(String path, Mode perms) {
+        var _path = getPath(path);
         var f = _path.toFile();
 
-        if (f.isDirectory()) {
-            var res = new StringBuilder();
+        checkMode(_path, perms);
 
-            for (var child : f.listFiles()) res.append(child.toString()).append('\n');
 
-            return new MemoryFile(res.toString().getBytes(), Permissions.READ);
+        if (f.isDirectory()) return MemoryFile.fromFileList(path, f.listFiles());
+        else try { return new PhysicalFile(path, perms); }
+        catch (FileNotFoundException e) { throw new FilesystemException(_path.toString(), FSCode.DOESNT_EXIST); }
+    }
+
+    @Override
+    public void create(String path, EntryType type) {
+        var _path = getPath(path);
+        var f = _path.toFile();
+
+        switch (type) {
+            case FILE:
+                try {
+                    if (!f.createNewFile()) throw new FilesystemException(_path.toString(), FSCode.ALREADY_EXISTS);
+                    else break;
+                } 
+                catch (IOException e) { throw new FilesystemException(_path.toString(), FSCode.NO_PERMISSIONS_RW); }
+            case FOLDER:
+                if (!f.mkdir()) throw new FilesystemException(_path.toString(), FSCode.ALREADY_EXISTS);
+                else break;
+            case NONE:
+            default:
+                if (!f.delete()) throw new FilesystemException(_path.toString(), FSCode.DOESNT_EXIST);
+                else break;
         }
-        else return new PhysicalFile(path, perms);
     }
 
     @Override
-    public boolean mkdir(String path) throws IOException, InterruptedException {
+    public FileStat stat(String path) {
         var _path = getPath(path);
-        var perms = getPerms(_path);
         var f = _path.toFile();
 
-        if (!perms.writable) return false;
-        else return f.mkdir();
-    }
+        if (!f.exists()) throw new FilesystemException(_path.toString(), FSCode.DOESNT_EXIST);
+        checkMode(_path, Mode.READ);
 
-    @Override
-    public EntryType type(String path) throws IOException, InterruptedException {
-        var _path = getPath(path);
-        var perms = getPerms(_path);
-        var f = _path.toFile();
-
-        if (perms == Permissions.NONE) return EntryType.NONE;
-        else if (f.isFile()) return EntryType.FILE;
-        else return EntryType.FOLDER;
-    }
-
-    @Override
-    public boolean rm(String path) throws IOException, InterruptedException {
-        var _path = getPath(path);
-        var perms = getPerms(_path);
-        var f = _path.toFile();
-
-        if (!perms.writable) return false;
-        else return f.delete();
+        return new FileStat(
+            f.canWrite() ? Mode.READ_WRITE : Mode.READ,
+            f.isFile() ? EntryType.FILE : EntryType.FOLDER
+        );
     }
 
     public PhysicalFilesystem(Path root) {
-        this.root = root;
+        this.root = root.toAbsolutePath().normalize();
     }
 }

src/me/topchetoeu/jscript/filesystem/RootFilesystem.java

@@ -0,0 +1,57 @@
+package me.topchetoeu.jscript.filesystem;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import me.topchetoeu.jscript.Filename;
+import me.topchetoeu.jscript.filesystem.FilesystemException.FSCode;
+import me.topchetoeu.jscript.permissions.PermissionsProvider;
+
+public class RootFilesystem implements Filesystem {
+    public final Map<String, Filesystem> protocols = new HashMap<>();
+    public final PermissionsProvider perms;
+
+    private boolean canRead(String _path) {
+        return perms.hasPermission("jscript.file.read:" + _path, '/');
+    }
+    private boolean canWrite(String _path) {
+        return perms.hasPermission("jscript.file.write:" + _path, '/');
+    }
+
+    private void modeAllowed(String _path, Mode mode) throws FilesystemException {
+        if (mode.readable && perms != null && !canRead(_path)) throw new FilesystemException(_path, FSCode.NO_PERMISSIONS_R);
+        if (mode.writable && perms != null && !canWrite(_path)) throw new FilesystemException(_path, FSCode.NO_PERMISSIONS_RW);
+    }
+
+    @Override public File open(String path, Mode perms) throws FilesystemException {
+        var filename = Filename.parse(path);
+        var protocol = protocols.get(filename.protocol);
+        if (protocol == null) throw new FilesystemException(filename.toString(), FSCode.DOESNT_EXIST);
+        modeAllowed(filename.toString(), perms);
+
+        try { return protocol.open(filename.path, perms); }
+        catch (FilesystemException e) { throw new FilesystemException(filename.toString(), e.code); }
+    }
+    @Override public void create(String path, EntryType type) throws FilesystemException {
+        var filename = Filename.parse(path);
+        var protocol = protocols.get(filename.protocol);
+        if (protocol == null) throw new FilesystemException(filename.toString(), FSCode.DOESNT_EXIST);
+        modeAllowed(filename.toString(), Mode.READ_WRITE);
+
+        try { protocol.create(filename.path, type); }
+        catch (FilesystemException e) { throw new FilesystemException(filename.toString(), e.code); }
+    }
+    @Override public FileStat stat(String path) throws FilesystemException {
+        var filename = Filename.parse(path);
+        var protocol = protocols.get(filename.protocol);
+        if (protocol == null) throw new FilesystemException(filename.toString(), FSCode.DOESNT_EXIST);
+        modeAllowed(filename.toString(), Mode.READ);
+
+        try { return protocol.stat(path); }
+        catch (FilesystemException e) { throw new FilesystemException(filename.toString(), e.code); }
+    }
+
+    public RootFilesystem(PermissionsProvider perms) {
+        this.perms = perms;
+    }
+}

src/me/topchetoeu/jscript/interop/NativeWrapperProvider.java

@@ -108,6 +108,12 @@ public class NativeWrapperProvider implements WrappersProvider {
         }
     }
 
+    public static String getName(Class<?> clazz) {
+        var classNat = clazz.getAnnotation(Native.class);
+        if (classNat != null && !classNat.value().trim().equals("")) return classNat.value().trim();
+        else return clazz.getSimpleName();
+    }
+
     /**
      * Generates a prototype for the given class.
      * The returned object will have appropriate wrappers for all instance members.
@@ -117,6 +123,8 @@ public class NativeWrapperProvider implements WrappersProvider {
     public static ObjectValue makeProto(Environment ctx, Class<?> clazz) {
         var res = new ObjectValue();
 
+        res.defineProperty(null, ctx.symbol("Symbol.typeName"), getName(clazz));
+
         for (var overload : clazz.getDeclaredMethods()) {
             var init = overload.getAnnotation(NativeInit.class);
             if (init == null || init.value() != InitType.PROTOTYPE) continue;
@@ -137,11 +145,7 @@ public class NativeWrapperProvider implements WrappersProvider {
      * @param clazz The class for which a constructor should be generated
      */
     public static FunctionValue makeConstructor(Environment ctx, Class<?> clazz) {
-        var name = clazz.getName();
-        var classNat = clazz.getAnnotation(Native.class);
-        if (classNat != null && !classNat.value().trim().equals("")) name = classNat.value().trim();
-
-        FunctionValue func = new OverloadFunction(name);
+        FunctionValue func = new OverloadFunction(getName(clazz));
 
         for (var overload : clazz.getDeclaredConstructors()) {
             var nat = overload.getAnnotation(Native.class);
@@ -256,7 +260,27 @@ public class NativeWrapperProvider implements WrappersProvider {
         constructors.put(clazz, value);
     }
 
+    private void initError() {
+        var proto = new ObjectValue();
+        proto.defineProperty(null, "message", new NativeFunction("message", (ctx, thisArg, args) -> {
+            if (thisArg instanceof Throwable) return ((Throwable)thisArg).getMessage();
+            else return null;
+        }));
+        proto.defineProperty(null, "name", new NativeFunction("name", (ctx, thisArg, args) -> getName(thisArg.getClass())));
+
+        var constr = makeConstructor(null, Throwable.class);
+        proto.defineProperty(null, "constructor", constr, true, false, false);
+        constr.defineProperty(null, "prototype", proto, true, false, false);
+
+        proto.setPrototype(null, getProto(Object.class));
+        constr.setPrototype(null, getConstr(Object.class));
+
+        setProto(Throwable.class, proto);
+        setConstr(Throwable.class, constr);
+    }
+
     public NativeWrapperProvider(Environment env) {
         this.env = env;
+        initError();
     }
 }

src/me/topchetoeu/jscript/interop/OverloadFunction.java

@@ -8,6 +8,7 @@ import java.util.List;
 import me.topchetoeu.jscript.Location;
 import me.topchetoeu.jscript.engine.Context;
 import me.topchetoeu.jscript.engine.values.FunctionValue;
+import me.topchetoeu.jscript.engine.values.NativeWrapper;
 import me.topchetoeu.jscript.engine.values.Values;
 import me.topchetoeu.jscript.exceptions.ConvertException;
 import me.topchetoeu.jscript.exceptions.EngineException;
@@ -92,7 +93,14 @@ public class OverloadFunction extends FunctionValue {
                     throw new InterruptException();
                 }
                 else {
-                    throw EngineException.ofError(e.getTargetException().getMessage()).add(name, loc);
+                    var target = e.getTargetException();
+                    var targetClass = target.getClass();
+                    var err = new NativeWrapper(e.getTargetException());
+
+                    err.defineProperty(ctx, "message", target.getMessage());
+                    err.defineProperty(ctx, "name", NativeWrapperProvider.getName(targetClass));
+
+                    throw new EngineException(err).add(name, loc);
                 }
             }
             catch (ReflectiveOperationException e) {

src/me/topchetoeu/jscript/js/bootstrap.js

@@ -1,7 +1,13 @@
 (function (_arguments) {
     var ts = _arguments[0];
-    var src = '', lib = _arguments[2].concat([ 'declare const exit: never;' ]).join(''), decls = '', version = 0;
+    var src = '', version = 0;
+    var lib = _arguments[2].concat([
+        'declare const exit: never; declare const go: any;',
+        'declare function getTsDeclarations(): string[];'
+    ]).join('');
     var libSnapshot = ts.ScriptSnapshot.fromString(lib);
+    var environments = {};
+    var declSnapshots = [];
 
     var settings = {
         outDir: "/out",
@@ -20,29 +26,41 @@
     var reg = ts.createDocumentRegistry();
     var service = ts.createLanguageService({
         getCurrentDirectory: function() { return "/"; },
-        getDefaultLibFileName: function() { return "/lib_.d.ts"; },
-        getScriptFileNames: function() { return [ "/src.ts", "/lib.d.ts", "/glob.d.ts" ]; },
+        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);
-            if (filename === "/glob.d.ts") return ts.ScriptSnapshot.fromString(decls);
+
+            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") return 0;
+            if (filename === "/lib.d.ts" || filename.startsWith("/glob.")) return 0;
             else return version;
         },
     }, reg);
 
-    service.getEmitOutput('/lib.d.ts');
-    log('Loaded libraries!');
+    service.getEmitOutput("/lib.d.ts");
+    log("Loaded libraries!");
 
-    function compile(code, filename) {
-        src = code, version++;
+    function compile(code, filename, env) {
+        src = code;
+        version++;
 
+        if (!environments[env.id]) environments[env.id] = []
+        declSnapshots = environments[env.id];
         var emit = service.getEmitOutput("/src.ts");
 
         var diagnostics = []
@@ -57,31 +75,37 @@
                     if (file === "src.ts") file = filename;
                     return file + ":" + (pos.line + 1) + ":" + (pos.character + 1) + ": " + message;
                 }
-                else return "Error: " + message;
+                else return message;
             });
 
         if (diagnostics.length > 0) {
-            throw new SyntaxError(diagnostics.join('\n'));
+            throw new SyntaxError(diagnostics.join("\n"));
         }
 
-        return {
-            result: emit.outputFiles[0].text,
-            declaration: emit.outputFiles[1].text
-        };
-    }
-
-    _arguments[1].compile = function (filename, code) {
-        var res = compile(filename, code);
+        var result = emit.outputFiles[0].text;
+        var declaration = emit.outputFiles[1].text;
+        
 
         return {
-            source: res.result,
+            source: result,
             runner: function(func) {
                 return function() {
                     var val = func.apply(this, arguments);
-                    decls += res.declaration;
+                    if (declaration !== '') {
+                        declSnapshots.push(ts.ScriptSnapshot.fromString(declaration));
+                    }
                     return val;
                 }
             }
+        };
+    }
+
+    function apply(env) {
+        env.compile = compile;
+        env.global.getTsDeclarations = function() {
+            return environments[env.id];
         }
     }
+
+    apply(_arguments[1]);
 })(arguments);

src/me/topchetoeu/jscript/js/lib.d.ts

@@ -482,6 +482,35 @@ 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>;
+    readonly mode: Promise<'' | 'r' | 'rw'>;
+
+    read(n: number): Promise<number[]>;
+    write(buff: number[]): Promise<void>;
+    close(): Promise<void>;
+    setPointer(val: number): Promise<void>;
+}
+interface Filesystem {
+    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>;
+}
+
+interface Encoding {
+    encode(val: string): number[];
+    decode(val: number[]): string;
+}
+
 declare var String: StringConstructor;
 //@ts-ignore
 declare const arguments: IArguments;
@@ -508,6 +537,8 @@ 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;

src/me/topchetoeu/jscript/lib/ArrayLib.java

@@ -4,16 +4,14 @@ import java.util.Iterator;
 import java.util.Stack;
 
 import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Environment;
 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.Values;
-import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
 import me.topchetoeu.jscript.interop.NativeGetter;
-import me.topchetoeu.jscript.interop.NativeInit;
 import me.topchetoeu.jscript.interop.NativeSetter;
 
 @Native("Array") public class ArrayLib {
@@ -25,10 +23,10 @@ import me.topchetoeu.jscript.interop.NativeSetter;
     }
     
     @Native(thisArg = true) public static ObjectValue values(Context ctx, ArrayValue thisArg) {
-        return Values.fromJavaIterable(ctx, thisArg);
+        return Values.toJSIterator(ctx, thisArg);
     }
     @Native(thisArg = true) public static ObjectValue keys(Context ctx, ArrayValue thisArg) {
-        return Values.fromJavaIterable(ctx, () -> new Iterator<Object>() {
+        return Values.toJSIterator(ctx, () -> new Iterator<Object>() {
             private int i = 0;
 
             @Override
@@ -43,7 +41,7 @@ import me.topchetoeu.jscript.interop.NativeSetter;
         });
     }
     @Native(thisArg = true) public static ObjectValue entries(Context ctx, ArrayValue thisArg) {
-        return Values.fromJavaIterable(ctx, () -> new Iterator<Object>() {
+        return Values.toJSIterator(ctx, () -> new Iterator<Object>() {
             private int i = 0;
 
             @Override
@@ -94,8 +92,11 @@ import me.topchetoeu.jscript.interop.NativeSetter;
     }
 
     @Native(thisArg = true) public static ArrayValue sort(Context ctx, ArrayValue arr, FunctionValue cmp) {
+        var defaultCmp = new NativeFunction("", (_ctx, thisArg, args) -> {
+            return Values.toString(ctx, args[0]).compareTo(Values.toString(ctx, args[1]));
+        });
         arr.sort((a, b) -> {
-            var res = Values.toNumber(ctx, cmp.call(ctx, null, a, b));
+            var res = Values.toNumber(ctx, (cmp == null ? defaultCmp : cmp).call(ctx, null, a, b));
             if (res < 0) return -1;
             if (res > 0) return 1;
             return 0;
@@ -309,8 +310,9 @@ import me.topchetoeu.jscript.interop.NativeSetter;
         return res;
     }
 
-    @Native(thisArg = true) public static ArrayValue splice(Context ctx, ArrayValue arr, int start, int deleteCount, Object ...items) {
+    @Native(thisArg = true) public static ArrayValue splice(Context ctx, ArrayValue arr, int start, Object _deleteCount, Object ...items) {
         start = normalizeI(arr.size(), start, true);
+        int deleteCount = _deleteCount == null ? arr.size() - 1 : (int)Values.toNumber(ctx, _deleteCount);
         deleteCount = normalizeI(arr.size(), deleteCount, true);
         if (start + deleteCount >= arr.size()) deleteCount = arr.size() - start;
 
@@ -323,9 +325,6 @@ import me.topchetoeu.jscript.interop.NativeSetter;
 
         return res;
     }
-    @Native(thisArg = true) public static ArrayValue splice(Context ctx, ArrayValue arr, int start) {
-        return splice(ctx, arr, start, arr.size() - start);
-    }
     @Native(thisArg = true) public static String toString(Context ctx, ArrayValue arr) {
         return join(ctx, arr, ",");
     }
@@ -371,8 +370,4 @@ import me.topchetoeu.jscript.interop.NativeSetter;
 
         return res;
     }
-
-    @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "Array");
-    }
 }

src/me/topchetoeu/jscript/lib/AsyncFunctionLib.java

@@ -1,7 +1,6 @@
 package me.topchetoeu.jscript.lib;
 
 import me.topchetoeu.jscript.engine.Context;
-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.values.CodeFunction;
@@ -21,7 +20,7 @@ import me.topchetoeu.jscript.interop.Native;
 
         private void next(Context ctx, Object inducedValue, Object inducedError) {
             Object res = null;
-            StackData.pushFrame(ctx, frame);
+            ctx.pushFrame(frame);
             ctx.pushEnv(frame.function.environment);
 
             awaiting = false;
@@ -40,7 +39,7 @@ import me.topchetoeu.jscript.interop.Native;
                 }
             }
 
-            StackData.popFrame(ctx, frame);
+            ctx.popFrame(frame);
 
             if (awaiting) {
                 PromiseLib.then(ctx, frame.pop(), new NativeFunction(this::fulfill), new NativeFunction(this::reject));

src/me/topchetoeu/jscript/lib/AsyncGeneratorLib.java

@@ -3,7 +3,6 @@ package me.topchetoeu.jscript.lib;
 import java.util.Map;
 
 import me.topchetoeu.jscript.engine.Context;
-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.values.NativeFunction;
@@ -29,7 +28,7 @@ import me.topchetoeu.jscript.interop.Native;
         }
 
         Object res = null;
-        StackData.pushFrame(ctx, frame);
+        ctx.pushFrame(frame);
         state = 0;
 
         while (state == 0) {
@@ -50,7 +49,7 @@ import me.topchetoeu.jscript.interop.Native;
             }
         }
 
-        StackData.popFrame(ctx, frame);
+        ctx.popFrame(frame);
 
         if (state == 1) {
             PromiseLib.then(ctx, frame.pop(), new NativeFunction(this::fulfill), new NativeFunction(this::reject));

src/me/topchetoeu/jscript/lib/BooleanLib.java

@@ -1,13 +1,10 @@
 package me.topchetoeu.jscript.lib;
 
 import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Environment;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
 import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
-import me.topchetoeu.jscript.interop.NativeInit;
 
 @Native("Boolean") public class BooleanLib {
     public static final BooleanLib TRUE = new BooleanLib(true);
@@ -30,7 +27,4 @@ import me.topchetoeu.jscript.interop.NativeInit;
     public BooleanLib(boolean val) {
         this.value = val;
     }
-    @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "Boolean");
-    }
 }

src/me/topchetoeu/jscript/lib/EncodingLib.java

@@ -0,0 +1,20 @@
+package me.topchetoeu.jscript.lib;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.interop.Native;
+
+@Native("Encoding")
+public class EncodingLib {
+    @Native public static ArrayValue encode(String value) {
+        var res = new ArrayValue();
+        for (var el : value.getBytes()) res.set(null, res.size(), (int)el);
+        return res;
+    }
+    @Native public static String decode(Context ctx, ArrayValue raw) {
+        var res = new byte[raw.size()];
+        for (var i = 0; i < raw.size(); i++) res[i] = (byte)Values.toNumber(ctx, raw.get(i));
+        return new String(res);
+    }
+}

src/me/topchetoeu/jscript/lib/ErrorLib.java

@@ -2,10 +2,10 @@ package me.topchetoeu.jscript.lib;
 
 import me.topchetoeu.jscript.engine.Context;
 import me.topchetoeu.jscript.engine.Environment;
-import me.topchetoeu.jscript.engine.StackData;
 import me.topchetoeu.jscript.engine.values.ArrayValue;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
 import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.engine.values.ObjectValue.PlaceholderProto;
 import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
@@ -51,8 +51,8 @@ import me.topchetoeu.jscript.interop.NativeInit;
         var target = new ObjectValue();
         if (thisArg instanceof ObjectValue) target = (ObjectValue)thisArg;
 
-        target.defineProperty(ctx, "stack", ArrayValue.of(ctx, StackData.stackTrace(ctx)));
-        target.defineProperty(ctx, "name", "Error");
+        target.setPrototype(PlaceholderProto.ERROR);
+        target.defineProperty(ctx, "stack", ArrayValue.of(ctx, ctx.stackTrace()));
         if (message == null) target.defineProperty(ctx, "message", "");
         else target.defineProperty(ctx, "message", Values.toString(ctx, message));
 
@@ -60,7 +60,6 @@ import me.topchetoeu.jscript.interop.NativeInit;
     }
 
     @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "Error");
         target.defineProperty(null, "name", "Error");
     }
 }

src/me/topchetoeu/jscript/lib/FileLib.java

@@ -0,0 +1,89 @@
+package me.topchetoeu.jscript.lib;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.filesystem.File;
+import me.topchetoeu.jscript.filesystem.FilesystemException;
+import me.topchetoeu.jscript.interop.Native;
+import me.topchetoeu.jscript.interop.NativeGetter;
+
+@Native("File")
+public class FileLib {
+    public final File file;
+
+    @NativeGetter public PromiseLib pointer(Context ctx) {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                return file.getPtr();
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+    @NativeGetter public PromiseLib length(Context ctx) {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                long curr = file.getPtr();
+                file.setPtr(0, 2);
+                long res = file.getPtr();
+                file.setPtr(curr, 0);
+                return res;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+    @NativeGetter public PromiseLib getMode(Context ctx) {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                return file.mode().name;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+
+    @Native public PromiseLib read(Context ctx, int n) {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                var buff = new byte[n];
+                var res = new ArrayValue();
+                int resI = file.read(buff);
+    
+                for (var i = resI - 1; i >= 0; i--) res.set(ctx, i, (int)buff[i]);
+                return res;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+    @Native public PromiseLib write(Context ctx, ArrayValue val) {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                var res = new byte[val.size()];
+
+                for (var i = 0; i < val.size(); i++) res[i] = (byte)Values.toNumber(ctx, val.get(i));
+                file.write(res);
+
+                return null;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+    @Native public PromiseLib close(Context ctx) {
+        return PromiseLib.await(ctx, () -> {
+            file.close();
+            return null;
+        });
+    }
+    @Native public PromiseLib setPointer(Context ctx, long ptr) {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                file.setPtr(ptr, 0);
+                return null;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+
+    public FileLib(File file) {
+        this.file = file;
+    }
+}

src/me/topchetoeu/jscript/lib/FilesystemLib.java

@@ -0,0 +1,165 @@
+package me.topchetoeu.jscript.lib;
+
+import java.io.IOException;
+import java.util.Iterator;
+import java.util.Stack;
+
+import me.topchetoeu.jscript.Filename;
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.exceptions.EngineException;
+import me.topchetoeu.jscript.filesystem.EntryType;
+import me.topchetoeu.jscript.filesystem.File;
+import me.topchetoeu.jscript.filesystem.FileStat;
+import me.topchetoeu.jscript.filesystem.Filesystem;
+import me.topchetoeu.jscript.filesystem.FilesystemException;
+import me.topchetoeu.jscript.filesystem.Mode;
+import me.topchetoeu.jscript.filesystem.FilesystemException.FSCode;
+import me.topchetoeu.jscript.interop.Native;
+
+@Native("Filesystem")
+public class FilesystemLib {
+    private static Filesystem fs(Context ctx) {
+        var env = ctx.environment();
+        if (env != null) {
+            var fs = ctx.environment().filesystem;
+            if (fs != null) return fs;
+        }
+        throw EngineException.ofError("Current environment doesn't have a file system.");
+    }
+
+    @Native public static PromiseLib open(Context ctx, String _path, String mode) {
+        var filename = Filename.parse(_path);
+        var _mode = Mode.parse(mode);
+
+        return PromiseLib.await(ctx, () -> {
+            try {
+                if (fs(ctx).stat(filename.path).type != EntryType.FILE) {
+                    throw new FilesystemException(filename.toString(), FSCode.NOT_FILE);
+                }
+
+                var file = fs(ctx).open(filename.path, _mode);
+                return new FileLib(file);
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+    @Native public static ObjectValue ls(Context ctx, String _path) throws IOException {
+        var filename = Filename.parse(_path);
+
+        return Values.toJSAsyncIterator(ctx, new Iterator<>() {
+            private boolean failed, done;
+            private File file;
+            private String nextLine;
+
+            private void update() {
+                if (done) return;
+                if (!failed) {
+                    if (file == null) {
+                        if (fs(ctx).stat(filename.path).type != EntryType.FOLDER) {
+                            throw new FilesystemException(filename.toString(), FSCode.NOT_FOLDER);
+                        }
+
+                        file = fs(ctx).open(filename.path, Mode.READ);
+                    }
+
+                    if (nextLine == null) {
+                        while (true) {
+                            nextLine = file.readLine();
+                            if (nextLine == null) {
+                                done = true;
+                                return;
+                            }
+                            nextLine = nextLine.trim();
+                            if (!nextLine.equals("")) break;
+                        }
+                    }
+                }
+            }
+
+            @Override
+            public boolean hasNext() {
+                try {
+                    update();
+                    return !done && !failed;
+                }
+                catch (FilesystemException e) { throw e.toEngineException(); }
+            }
+            @Override
+            public String next() {
+                try {
+                    update();
+                    var res = nextLine;
+                    nextLine = null;
+                    return res;
+                }
+                catch (FilesystemException e) { throw e.toEngineException(); }
+            }
+        });
+    }
+    @Native public static PromiseLib mkdir(Context ctx, String _path) throws IOException {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                fs(ctx).create(Filename.parse(_path).toString(), EntryType.FOLDER);
+                return null;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+
+    }
+    @Native public static PromiseLib mkfile(Context ctx, String _path) throws IOException {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                fs(ctx).create(Filename.parse(_path).toString(), EntryType.FILE);
+                return null;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+    @Native public static PromiseLib rm(Context ctx, String _path, boolean recursive) throws IOException {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                if (!recursive) fs(ctx).create(Filename.parse(_path).toString(), EntryType.NONE);
+                else {
+                    var stack = new Stack<String>();
+                    stack.push(_path);
+
+                    while (!stack.empty()) {
+                        var path = Filename.parse(stack.pop()).toString();
+                        FileStat stat;
+
+                        try { stat = fs(ctx).stat(path); }
+                        catch (FilesystemException e) { continue; }
+
+                        if (stat.type == EntryType.FOLDER) {
+                            for (var el : fs(ctx).open(path, Mode.READ).readToString().split("\n")) stack.push(el);
+                        }
+                        else fs(ctx).create(path, EntryType.NONE);
+                    }
+                }
+                return null;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+    @Native public static PromiseLib stat(Context ctx, String _path) throws IOException {
+        return PromiseLib.await(ctx, () -> {
+            try {
+                var stat = fs(ctx).stat(_path);
+                var res = new ObjectValue();
+
+                res.defineProperty(ctx, "type", stat.type.name);
+                res.defineProperty(ctx, "mode", stat.mode.name);
+                return res;
+            }
+            catch (FilesystemException e) { throw e.toEngineException(); }
+        });
+    }
+    @Native public static PromiseLib exists(Context ctx, String _path) throws IOException {
+        return PromiseLib.await(ctx, () -> {
+            try { fs(ctx).stat(_path); return true; }
+            catch (FilesystemException e) { return false; }
+        });
+    }
+}

src/me/topchetoeu/jscript/lib/FunctionLib.java

@@ -2,16 +2,12 @@ package me.topchetoeu.jscript.lib;
 
 import me.topchetoeu.jscript.Location;
 import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Environment;
 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.NativeFunction;
-import me.topchetoeu.jscript.engine.values.ObjectValue;
 import me.topchetoeu.jscript.exceptions.EngineException;
-import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
-import me.topchetoeu.jscript.interop.NativeInit;
 
 @Native("Function") public class FunctionLib {
     @Native(thisArg = true) public static Object location(Context ctx, FunctionValue func) {
@@ -43,7 +39,7 @@ import me.topchetoeu.jscript.interop.NativeInit;
         });
     }
     @Native(thisArg = true) public static String toString(Context ctx, Object func) {
-        return "function (...) { ... }";
+        return func.toString();
     }
 
     @Native public static FunctionValue async(FunctionValue func) {
@@ -55,8 +51,4 @@ import me.topchetoeu.jscript.interop.NativeInit;
     @Native public static FunctionValue generator(FunctionValue func) {
         return new GeneratorFunctionLib(func);
     }
-
-    @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "Function");
-    }
 }

src/me/topchetoeu/jscript/lib/GeneratorLib.java

@@ -1,7 +1,6 @@
 package me.topchetoeu.jscript.lib;
 
 import me.topchetoeu.jscript.engine.Context;
-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.values.ObjectValue;
@@ -25,7 +24,7 @@ import me.topchetoeu.jscript.interop.Native;
         }
 
         Object res = null;
-        StackData.pushFrame(ctx, frame);
+        ctx.pushFrame(frame);
         yielding = false;
 
         while (!yielding) {
@@ -43,7 +42,7 @@ import me.topchetoeu.jscript.interop.Native;
             }
         }
 
-        StackData.popFrame(ctx, frame);
+        ctx.popFrame(frame);
         if (done) frame = null;
         else res = frame.pop();
 

src/me/topchetoeu/jscript/lib/Internals.java

@@ -18,12 +18,15 @@ public class Internals {
     private static final DataKey<Integer> I = new DataKey<>();
 
 
-    @Native public static void log(Context ctx, Object ...args) {
+    @Native public static Object log(Context ctx, Object ...args) {
         for (var arg : args) {
             Values.printValue(ctx, arg);
             System.out.print(" ");
         }
         System.out.println();
+
+        if (args.length == 0) return null;
+        else return args[0];
     }
     @Native public static String readline(Context ctx) {
         try {
@@ -110,12 +113,14 @@ public class Internals {
         return Double.POSITIVE_INFINITY;
     }
 
-    public void apply(Environment env) {
+    public static Environment apply(Environment env) {
         var wp = env.wrappers;
         var glob = env.global = new GlobalScope(wp.getNamespace(Internals.class));
 
         glob.define(null, "Math", false, wp.getNamespace(MathLib.class));
         glob.define(null, "JSON", false, wp.getNamespace(JSONLib.class));
+        glob.define(null, "Encoding", false, wp.getNamespace(EncodingLib.class));
+        glob.define(null, "Filesystem", false, wp.getNamespace(FilesystemLib.class));
 
         glob.define(null, "Date", false, wp.getConstr(DateLib.class));
         glob.define(null, "Object", false, wp.getConstr(ObjectLib.class));
@@ -154,6 +159,6 @@ public class Internals {
         wp.getProto(ObjectLib.class).setPrototype(null, null);
         env.regexConstructor = wp.getConstr(RegExpLib.class);
 
-        System.out.println("Loaded polyfills!");
+        return env;
     }
 }

src/me/topchetoeu/jscript/lib/MapLib.java

@@ -35,15 +35,15 @@ import me.topchetoeu.jscript.interop.NativeGetter;
         var res = map.entrySet().stream().map(v -> {
             return new ArrayValue(ctx, v.getKey(), v.getValue());
         }).collect(Collectors.toList());
-        return Values.fromJavaIterator(ctx, res.iterator());
+        return Values.toJSIterator(ctx, res.iterator());
     }
     @Native public ObjectValue keys(Context ctx) {
         var res = new ArrayList<>(map.keySet());
-        return Values.fromJavaIterator(ctx, res.iterator());
+        return Values.toJSIterator(ctx, res.iterator());
     }
     @Native public ObjectValue values(Context ctx) {
         var res = new ArrayList<>(map.values());
-        return Values.fromJavaIterator(ctx, res.iterator());
+        return Values.toJSIterator(ctx, res.iterator());
     }
 
     @Native public Object get(Object key) {
@@ -68,7 +68,7 @@ import me.topchetoeu.jscript.interop.NativeGetter;
     }
 
     @Native public MapLib(Context ctx, Object iterable) {
-        for (var el : Values.toJavaIterable(ctx, iterable)) {
+        for (var el : Values.fromJSIterator(ctx, iterable)) {
             try {
                 set(Values.getMember(ctx, el, 0), Values.getMember(ctx, el, 1));
             }

src/me/topchetoeu/jscript/lib/NumberLib.java

@@ -1,13 +1,10 @@
 package me.topchetoeu.jscript.lib;
 
 import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Environment;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
 import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
-import me.topchetoeu.jscript.interop.NativeInit;
 
 @Native("Number") public class NumberLib {
     @Native public static final double EPSILON = java.lang.Math.ulp(1.0);
@@ -52,8 +49,4 @@ import me.topchetoeu.jscript.interop.NativeInit;
     public NumberLib(double val) {
         this.value = val;
     }
-
-    @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "Number");
-    }
 }

src/me/topchetoeu/jscript/lib/ObjectLib.java

@@ -1,17 +1,14 @@
 package me.topchetoeu.jscript.lib;
 
 import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Environment;
 import me.topchetoeu.jscript.engine.values.ArrayValue;
 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;
-import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
-import me.topchetoeu.jscript.interop.NativeInit;
 
 @Native("Object") public class ObjectLib {
     @Native public static ObjectValue assign(Context ctx, ObjectValue dst, Object... src) {
@@ -143,7 +140,7 @@ import me.topchetoeu.jscript.interop.NativeInit;
     @Native public static ObjectValue fromEntries(Context ctx, Object iterable) {
         var res = new ObjectValue();
 
-        for (var el : Values.toJavaIterable(ctx, iterable)) {
+        for (var el : Values.fromJSIterator(ctx, iterable)) {
             if (el instanceof ArrayValue) {
                 res.defineProperty(ctx, ((ArrayValue)el).get(0), ((ArrayValue)el).get(1));
             }
@@ -212,8 +209,4 @@ import me.topchetoeu.jscript.interop.NativeInit;
         // else if (arg instanceof Symbol) return SymbolPolyfill.constructor(ctx, thisArg, arg);
         else return arg;
     }
-
-    @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "Object");
-    }
 }

src/me/topchetoeu/jscript/lib/PromiseLib.java

@@ -5,7 +5,6 @@ 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.values.ArrayValue;
 import me.topchetoeu.jscript.engine.values.FunctionValue;
 import me.topchetoeu.jscript.engine.values.NativeFunction;
@@ -13,12 +12,12 @@ import me.topchetoeu.jscript.engine.values.NativeWrapper;
 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.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
-import me.topchetoeu.jscript.interop.NativeInit;
 
 @Native("Promise") public class PromiseLib {
+    public static interface PromiseRunner {
+        Object run();
+    }
     private static class Handle {
         public final Context ctx;
         public final FunctionValue fulfilled;
@@ -171,9 +170,7 @@ import me.topchetoeu.jscript.interop.NativeInit;
         }
 
         var fulfillHandle = new NativeFunction(null, (_ctx, th, a) -> {
-            try {
-                res.fulfill(ctx, Values.convert(ctx, fulfill.call(ctx, null, a[0]), Object.class));
-            }
+            try { res.fulfill(ctx, Values.convert(ctx, fulfill.call(ctx, null, a[0]), Object.class)); }
             catch (EngineException err) { res.reject(ctx, err.value); }
             return null;
         });
@@ -234,7 +231,7 @@ import me.topchetoeu.jscript.interop.NativeInit;
     private boolean handled = false;
     private Object val;
 
-    public void fulfill(Context ctx, Object val) {
+    public synchronized void fulfill(Context ctx, Object val) {
         if (this.state != STATE_PENDING) return;
 
         if (val instanceof PromiseLib) ((PromiseLib)val).handle(ctx,
@@ -242,12 +239,12 @@ import me.topchetoeu.jscript.interop.NativeInit;
             new NativeFunction(null, (e, th, a) -> { this.reject(ctx, a[0]); return null; })
         );
         else {
-            Object next;
-            try { next = Values.getMember(ctx, val, "next"); }
-            catch (IllegalArgumentException e) { next = null; }
+            Object then;
+            try { then = Values.getMember(ctx, val, "then"); }
+            catch (IllegalArgumentException e) { then = null; }
 
             try {
-                if (next instanceof FunctionValue) ((FunctionValue)next).call(ctx, val,
+                if (then instanceof FunctionValue) ((FunctionValue)then).call(ctx, val,
                     new NativeFunction((e, _thisArg, a) -> { this.fulfill(ctx, a.length > 0 ? a[0] : null); return null; }),
                     new NativeFunction((e, _thisArg, a) -> { this.reject(ctx, a.length > 0 ? a[0] : null); return null; })
                 );
@@ -255,9 +252,13 @@ import me.topchetoeu.jscript.interop.NativeInit;
                     this.val = val;
                     this.state = STATE_FULFILLED;
 
-                    for (var handle : handles) handle.fulfilled.call(handle.ctx, null, val);
-
-                    handles = null;
+                    ctx.engine.pushMsg(true, ctx, new NativeFunction((_ctx, _thisArg, _args) -> {
+                        for (var handle : handles) {
+                            handle.fulfilled.call(handle.ctx, null, val);
+                        }
+                        handles = null;
+                        return null;
+                    }), null);
                 }
             }
             catch (EngineException err) {
@@ -265,7 +266,7 @@ import me.topchetoeu.jscript.interop.NativeInit;
             }
         }
     }
-    public void reject(Context ctx, Object val) {
+    public synchronized void reject(Context ctx, Object val) {
         if (this.state != STATE_PENDING) return;
 
         if (val instanceof PromiseLib) ((PromiseLib)val).handle(ctx,
@@ -273,12 +274,12 @@ import me.topchetoeu.jscript.interop.NativeInit;
             new NativeFunction(null, (e, th, a) -> { this.reject(ctx, a[0]); return null; })
         );
         else {
-            Object next;
-            try { next = Values.getMember(ctx, val, "next"); }
-            catch (IllegalArgumentException e) { next = null; }
+            Object then;
+            try { then = Values.getMember(ctx, val, "then"); }
+            catch (IllegalArgumentException e) { then = null; }
 
             try {
-                if (next instanceof FunctionValue) ((FunctionValue)next).call(ctx, val,
+                if (then instanceof FunctionValue) ((FunctionValue)then).call(ctx, val,
                     new NativeFunction((e, _thisArg, a) -> { this.reject(ctx, a.length > 0 ? a[0] : null); return null; }),
                     new NativeFunction((e, _thisArg, a) -> { this.reject(ctx, a.length > 0 ? a[0] : null); return null; })
                 );
@@ -286,19 +287,14 @@ import me.topchetoeu.jscript.interop.NativeInit;
                     this.val = val;
                     this.state = STATE_REJECTED;
 
-                    for (var handle : handles) handle.rejected.call(handle.ctx, null, val);
-                    if (handles.size() == 0) {
-                        ctx.engine.pushMsg(true, ctx, new NativeFunction((_ctx, _thisArg, _args) -> {
-                            if (!handled) {
-                                Values.printError(new EngineException(val).setCtx(ctx.environment(), ctx.engine), "(in promise)");
-                                throw new InterruptException();
-                            }
-
-                            return null;
-                        }), null);
-                    }
-
-                    handles = null;
+                    ctx.engine.pushMsg(true, ctx, new NativeFunction((_ctx, _thisArg, _args) -> {
+                        for (var handle : handles) handle.rejected.call(handle.ctx, null, val);
+                        if (!handled) {
+                            Values.printError(new EngineException(val).setCtx(ctx.environment(), ctx.engine), "(in promise)");
+                        }
+                        handles = null;
+                        return null;
+                    }), null);
                 }
             }
             catch (EngineException err) {
@@ -353,7 +349,18 @@ import me.topchetoeu.jscript.interop.NativeInit;
         this(STATE_PENDING, null);
     }
 
-    @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "Promise");
+    public static PromiseLib await(Context ctx, PromiseRunner runner) {
+        var res = new PromiseLib();
+
+        new Thread(() -> {
+            try {
+                res.fulfill(ctx, runner.run());
+            }
+            catch (EngineException e) {
+                res.reject(ctx, e.value);
+            }
+        }, "Promisifier").start();
+
+        return res;
     }
 }

src/me/topchetoeu/jscript/lib/RangeErrorLib.java

@@ -3,6 +3,7 @@ package me.topchetoeu.jscript.lib;
 import me.topchetoeu.jscript.engine.Context;
 import me.topchetoeu.jscript.engine.Environment;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.ObjectValue.PlaceholderProto;
 import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
@@ -11,11 +12,11 @@ import me.topchetoeu.jscript.interop.NativeInit;
 @Native("RangeError") public class RangeErrorLib extends ErrorLib {
     @NativeConstructor(thisArg = true) public static ObjectValue constructor(Context ctx, Object thisArg, Object message) {
         var target = ErrorLib.constructor(ctx, thisArg, message);
+        target.setPrototype(PlaceholderProto.SYNTAX_ERROR);
         target.defineProperty(ctx, "name", "RangeError");
         return target;
     }
     @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "RangeError");
         target.defineProperty(null, "name", "RangeError");
     }
 }

src/me/topchetoeu/jscript/lib/RegExpLib.java

@@ -153,7 +153,7 @@ import me.topchetoeu.jscript.interop.NativeGetter;
     @Native("@@Symbol.matchAll") public Object matchAll(Context ctx, String target) {
         var pattern = new RegExpLib(this.source, this.flags() + "g");
 
-        return Values.fromJavaIterator(ctx, new Iterator<Object>() {
+        return Values.toJSIterator(ctx, new Iterator<Object>() {
             private Object val = null;
             private boolean updated = false;
 

src/me/topchetoeu/jscript/lib/SetLib.java

@@ -22,15 +22,15 @@ import me.topchetoeu.jscript.interop.NativeGetter;
 
     @Native public ObjectValue entries(Context ctx) {
         var res = set.stream().map(v -> new ArrayValue(ctx, v, v)).collect(Collectors.toList());
-        return Values.fromJavaIterator(ctx, res.iterator());
+        return Values.toJSIterator(ctx, res.iterator());
     }
     @Native public ObjectValue keys(Context ctx) {
         var res = new ArrayList<>(set);
-        return Values.fromJavaIterator(ctx, res.iterator());
+        return Values.toJSIterator(ctx, res.iterator());
     }
     @Native public ObjectValue values(Context ctx) {
         var res = new ArrayList<>(set);
-        return Values.fromJavaIterator(ctx, res.iterator());
+        return Values.toJSIterator(ctx, res.iterator());
     }
 
     @Native public Object add(Object key) {
@@ -58,6 +58,6 @@ import me.topchetoeu.jscript.interop.NativeGetter;
     }
 
     @Native public SetLib(Context ctx, Object iterable) {
-        for (var el : Values.toJavaIterable(ctx, iterable)) add(el);
+        for (var el : Values.fromJSIterator(ctx, iterable)) add(el);
     }
 }

src/me/topchetoeu/jscript/lib/StringLib.java

@@ -3,17 +3,14 @@ package me.topchetoeu.jscript.lib;
 import java.util.regex.Pattern;
 
 import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Environment;
 import me.topchetoeu.jscript.engine.values.ArrayValue;
 import me.topchetoeu.jscript.engine.values.FunctionValue;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
 import me.topchetoeu.jscript.engine.values.Values;
 import me.topchetoeu.jscript.exceptions.EngineException;
-import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
 import me.topchetoeu.jscript.interop.NativeGetter;
-import me.topchetoeu.jscript.interop.NativeInit;
 
 // TODO: implement index wrapping properly
 @Native("String") public class StringLib {
@@ -263,8 +260,4 @@ import me.topchetoeu.jscript.interop.NativeInit;
     public StringLib(String val) {
         this.value = val;
     }
-
-    @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "String");
-    }
 }

src/me/topchetoeu/jscript/lib/SymbolLib.java

@@ -4,16 +4,13 @@ import java.util.HashMap;
 import java.util.Map;
 
 import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.Environment;
 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.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
 import me.topchetoeu.jscript.interop.NativeGetter;
-import me.topchetoeu.jscript.interop.NativeInit;
 
 @Native("Symbol") public class SymbolLib {
     private static final Map<String, Symbol> symbols = new HashMap<>();
@@ -63,8 +60,4 @@ import me.topchetoeu.jscript.interop.NativeInit;
     public SymbolLib(Symbol val) {
         this.value = val;
     }
-
-    @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "Symbol");
-    }
 }

src/me/topchetoeu/jscript/lib/SyntaxErrorLib.java

@@ -3,6 +3,7 @@ package me.topchetoeu.jscript.lib;
 import me.topchetoeu.jscript.engine.Context;
 import me.topchetoeu.jscript.engine.Environment;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.ObjectValue.PlaceholderProto;
 import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
@@ -11,11 +12,10 @@ import me.topchetoeu.jscript.interop.NativeInit;
 @Native("SyntaxError") public class SyntaxErrorLib extends ErrorLib {
     @NativeConstructor(thisArg = true) public static ObjectValue constructor(Context ctx, Object thisArg, Object message) {
         var target = ErrorLib.constructor(ctx, thisArg, message);
-        target.defineProperty(ctx, "name", "SyntaxError");
+        target.setPrototype(PlaceholderProto.SYNTAX_ERROR);
         return target;
     }
     @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "SyntaxError");
         target.defineProperty(null, "name", "SyntaxError");
     }
 }

src/me/topchetoeu/jscript/lib/TypeErrorLib.java

@@ -3,6 +3,7 @@ package me.topchetoeu.jscript.lib;
 import me.topchetoeu.jscript.engine.Context;
 import me.topchetoeu.jscript.engine.Environment;
 import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.ObjectValue.PlaceholderProto;
 import me.topchetoeu.jscript.interop.InitType;
 import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
@@ -11,11 +12,10 @@ import me.topchetoeu.jscript.interop.NativeInit;
 @Native("TypeError") public class TypeErrorLib extends ErrorLib {
     @NativeConstructor(thisArg = true) public static ObjectValue constructor(Context ctx, Object thisArg, Object message) {
         var target = ErrorLib.constructor(ctx, thisArg, message);
-        target.defineProperty(ctx, "name", "TypeError");
+        target.setPrototype(PlaceholderProto.SYNTAX_ERROR);
         return target;
     }
     @NativeInit(InitType.PROTOTYPE) public static void init(Environment env, ObjectValue target) {
-        target.defineProperty(null, env.symbol("Symbol.typeName"), "TypeError");
         target.defineProperty(null, "name", "TypeError");
     }
 }

src/me/topchetoeu/jscript/parsing/Parsing.java

@@ -11,7 +11,6 @@ import java.util.TreeSet;
 import me.topchetoeu.jscript.Filename;
 import me.topchetoeu.jscript.Location;
 import me.topchetoeu.jscript.compilation.*;
-import me.topchetoeu.jscript.compilation.Instruction.Type;
 import me.topchetoeu.jscript.compilation.VariableDeclareStatement.Pair;
 import me.topchetoeu.jscript.compilation.control.*;
 import me.topchetoeu.jscript.compilation.control.SwitchStatement.SwitchCase;
@@ -1896,10 +1895,7 @@ public class Parsing {
             res.add(Instruction.throwSyntax(e));
         }
 
-        if (res.size() != 0 && res.get(res.size() - 1).type == Type.DISCARD) {
-            res.set(res.size() - 1, Instruction.ret());
-        }
-        else res.add(Instruction.ret());
+        res.add(Instruction.ret());
 
         return new CodeFunction(environment, "", subscope.localsCount(), 0, new ValueVariable[0], new FunctionBody(res.array(), subscope.captures(), subscope.locals()));
     }

src/me/topchetoeu/jscript/permissions/Permission.java

@@ -0,0 +1,124 @@
+package me.topchetoeu.jscript.permissions;
+
+import java.util.LinkedList;
+
+public class Permission {
+    private static class State {
+        public final int predI, trgI, wildcardI;
+        public final boolean wildcard;
+
+        @Override
+        public String toString() {
+            return String.format("State [pr=%s;trg=%s;wildN=%s;wild=%s]", predI, trgI, wildcardI, wildcard);
+        }
+
+        public State(int predicateI, int targetI, int wildcardI, boolean wildcard) {
+            this.predI = predicateI;
+            this.trgI = targetI;
+            this.wildcardI = wildcardI;
+            this.wildcard = wildcard;
+        }
+    }
+
+    public final String namespace;
+    public final String value;
+
+    public boolean match(Permission perm) {
+        if (!Permission.match(namespace, perm.namespace, '.')) return false;
+        if (value == null || perm.value == null) return true;
+        return Permission.match(value, perm.value);
+    }
+    public boolean match(Permission perm, char delim) {
+        if (!Permission.match(namespace, perm.namespace, '.')) return false;
+        if (value == null || perm.value == null) return true;
+        return Permission.match(value, perm.value, delim);
+    }
+
+    public boolean match(String perm) {
+        return match(new Permission(perm));
+    }
+    public boolean match(String perm, char delim) {
+        return match(new Permission(perm), delim);
+    }
+
+    @Override
+    public String toString() {
+        if (value != null) return namespace + ":" + value;
+        else return namespace;
+    }
+
+    public Permission(String raw) {
+        var i = raw.indexOf(':');
+
+        if (i > 0) {
+            value = raw.substring(i + 1);
+            namespace = raw.substring(0, i);
+        }
+        else {
+            value = null;
+            namespace = raw;
+        }
+    }
+
+    public static boolean match(String predicate, String target, char delim) {
+        if (predicate.equals("")) return target.equals("");
+
+        var queue = new LinkedList<State>();
+        queue.push(new State(0, 0, 0, false));
+
+        while (!queue.isEmpty()) {
+            var state = queue.poll();
+            var predEnd = state.predI >= predicate.length();
+
+            if (state.trgI >= target.length()) return predEnd;
+            var predC = predEnd ? 0 : predicate.charAt(state.predI);
+            var trgC = target.charAt(state.trgI);
+
+            if (state.wildcard) {
+                if (state.wildcardI == 2 || trgC != delim) {
+                    queue.add(new State(state.predI, state.trgI + 1, state.wildcardI, true));
+                }
+                queue.add(new State(state.predI, state.trgI, 0, false));
+            }
+            else if (predC == '*') {
+                queue.add(new State(state.predI + 1, state.trgI, state.wildcardI + 1, false));
+            }
+            else if (state.wildcardI > 0) {
+                if (state.wildcardI > 2) throw new IllegalArgumentException("Too many sequential stars.");
+                queue.add(new State(state.predI, state.trgI, state.wildcardI, true));
+            }
+            else if (!predEnd && (predC == '?' || predC == trgC)) {
+                queue.add(new State(state.predI + 1, state.trgI + 1, 0, false));
+            }
+        }
+
+        return false;
+    }
+    public static boolean match(String predicate, String target) {
+        if (predicate.equals("")) return target.equals("");
+
+        var queue = new LinkedList<State>();
+        queue.push(new State(0, 0, 0, false));
+
+        while (!queue.isEmpty()) {
+            var state = queue.poll();
+
+            if (state.predI >= predicate.length() || state.trgI >= target.length()) {
+                return state.predI >= predicate.length() && state.trgI >= target.length();
+            }
+
+            var predC = predicate.charAt(state.predI);
+            var trgC = target.charAt(state.trgI);
+
+            if (predC == '*') {
+                queue.add(new State(state.predI, state.trgI + 1, state.wildcardI, true));
+                queue.add(new State(state.predI + 1, state.trgI, 0, false));
+            }
+            else if (predC == '?' || predC == trgC) {
+                queue.add(new State(state.predI + 1, state.trgI + 1, 0, false));
+            }
+        }
+
+        return false;
+    }
+}

src/me/topchetoeu/jscript/permissions/PermissionsManager.java

@@ -0,0 +1,34 @@
+package me.topchetoeu.jscript.permissions;
+
+import java.util.ArrayList;
+
+public class PermissionsManager implements PermissionsProvider {
+    public static final PermissionsProvider ALL_PERMS = new PermissionsManager().add(new Permission("**"));
+
+    public final ArrayList<Permission> allowed = new ArrayList<>();
+    public final ArrayList<Permission> denied = new ArrayList<>();
+
+    public PermissionsProvider add(Permission perm) {
+        allowed.add(perm);
+        return this;
+    }
+    public PermissionsProvider add(String perm) {
+        allowed.add(new Permission(perm));
+        return this;
+    }
+
+    @Override
+    public boolean hasPermission(Permission perm, char delim) {
+        for (var el : denied) if (el.match(perm, delim)) return false;
+        for (var el : allowed) if (el.match(perm, delim)) return true;
+
+        return false;
+    }
+    @Override
+    public boolean hasPermission(Permission perm) {
+        for (var el : denied) if (el.match(perm)) return false;
+        for (var el : allowed) if (el.match(perm)) return true;
+
+        return false;
+    }
+}

src/me/topchetoeu/jscript/permissions/PermissionsProvider.java

@@ -0,0 +1,13 @@
+package me.topchetoeu.jscript.permissions;
+
+public interface PermissionsProvider {
+    boolean hasPermission(Permission perm, char delim);
+    boolean hasPermission(Permission perm);
+
+    default boolean hasPermission(String perm, char delim) {
+        return hasPermission(new Permission(perm), delim);
+    }
+    default boolean hasPermission(String perm) {
+        return hasPermission(new Permission(perm));
+    }
+}