refactor: some minor fixes, rewrite README example

.github/workflows/tagged-release.yml

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

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) { }
 }
 ```

src/me/topchetoeu/jscript/Main.java

@@ -8,12 +8,9 @@ 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;
@@ -47,61 +44,42 @@ public class Main {
         System.out.println(String.format("Running %s v%s by %s", Metadata.NAME, Metadata.VERSION, Metadata.AUTHOR));
         engine = new Engine(true);
 
-        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));
+        
+        env = Internals.apply(new Environment(null, null, null));
+
+        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");
+            }
+        });
 
         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();
-
         try {
-            var tsEnv = env.child();
-            tsEnv.global.define(null, "module", false, new ObjectValue());
+            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,

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/engine/Context.java

@@ -54,6 +54,11 @@ public class Context {
         this.engine = engine;
     }
     public Context(Engine engine) {
-        this(engine, null);
+        this(engine, (Data)null);
+    }
+    public Context(Engine engine, Environment env) {
+        this(engine, (Data)null);
+        this.pushEnv(env);
+        
     }
 }

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

@@ -58,7 +58,7 @@ public class Engine implements DebugController {
     private LinkedBlockingDeque<Task> microTasks = new LinkedBlockingDeque<>();
 
     public final int id = ++nextId;
-    public final Data data = new Data().set(StackData.MAX_FRAMES, 200);
+    public final Data data = new Data().set(StackData.MAX_FRAMES, 10000);
     public final boolean debugging;
     private final HashMap<Filename, String> sources = new HashMap<>();
     private final HashMap<Filename, TreeSet<Location>> bpts = new HashMap<>();

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

@@ -17,7 +17,8 @@ public class StackData {
     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!");
+        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) {

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

@@ -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;

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

@@ -596,6 +596,16 @@ public class Values {
         return fromJavaIterator(ctx, it.iterator());
     }
 
+    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);
@@ -643,7 +653,7 @@ 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 +671,13 @@ 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/js/bootstrap.js

@@ -1,6 +1,6 @@
 (function (_arguments) {
     var ts = _arguments[0];
-    var src = '', lib = _arguments[2].concat([ 'declare const exit: never;' ]).join(''), decls = '', version = 0;
+    var src = '', lib = _arguments[2].concat([ 'declare const exit: never; declare const go: any;' ]).join(''), decls = '', version = 0;
     var libSnapshot = ts.ScriptSnapshot.fromString(lib);
 
     var settings = {
@@ -20,11 +20,11 @@
     var reg = ts.createDocumentRegistry();
     var service = ts.createLanguageService({
         getCurrentDirectory: function() { return "/"; },
-        getDefaultLibFileName: function() { return "/lib_.d.ts"; },
+        getDefaultLibFileName: function() { return "/lib.d.ts"; },
         getScriptFileNames: function() { return [ "/src.ts", "/lib.d.ts", "/glob.d.ts" ]; },
         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);
@@ -37,11 +37,12 @@
         },
     }, reg);
 
-    service.getEmitOutput('/lib.d.ts');
-    log('Loaded libraries!');
+    service.getEmitOutput("/lib.d.ts");
+    log("Loaded libraries!");
 
     function compile(code, filename) {
-        src = code, version++;
+        src = code;
+        version++;
 
         var emit = service.getEmitOutput("/src.ts");
 
@@ -61,7 +62,7 @@
             });
 
         if (diagnostics.length > 0) {
-            throw new SyntaxError(diagnostics.join('\n'));
+            throw new SyntaxError(diagnostics.join("\n"));
         }
 
         return {

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

@@ -309,8 +309,9 @@ 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 +324,6 @@ 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, ",");
     }

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 {
@@ -110,7 +113,7 @@ 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));
 
@@ -154,6 +157,6 @@ public class Internals {
         wp.getProto(ObjectLib.class).setPrototype(null, null);
         env.regexConstructor = wp.getConstr(RegExpLib.class);
 
-        System.out.println("Loaded polyfills!");
+        return env;
     }
 }