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refactor: some minor fixes, rewrite README example

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TopchetoEU 2023-11-06 10:55:38 +02:00
parent f5d1287948
commit fdfa8d7713
Signed by: topchetoeu
GPG Key ID: 6531B8583E5F6ED4
7 changed files with 58 additions and 170152 deletions
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37
README.md
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@ -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 (EngineException e) { Values.printError(e, ""); }
catch (SyntaxException ex) {
System.out.println("Syntax error:" + ex.msg);
}
catch (InterruptedException _e) { return; }
}
catch (IOException | InterruptedException e) { return; }
catch (IOException e) { }
}
```

38
src/me/topchetoeu/jscript/Main.java
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@ -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;
@ -47,16 +44,11 @@ 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));
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 = Internals.apply(new Environment(null, null, null));
env.global.define("exit", _ctx -> {
exited[0] = true;
@ -72,36 +64,22 @@ public class Main {
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();
engineTask = engine.start();
debugTask = server.start(new InetSocketAddress("127.0.0.1", 9229), true);
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,

2
src/me/topchetoeu/jscript/compilation/CompoundStatement.java
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@ -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());
}
}

7
src/me/topchetoeu/jscript/engine/Context.java
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@ -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);
}
}

1
src/me/topchetoeu/jscript/engine/debug/SimpleDebugger.java
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@ -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;

170093
src/me/topchetoeu/jscript/js/ts.js
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File diff suppressed because one or more lines are too long

4
src/me/topchetoeu/jscript/lib/Internals.java
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@ -113,7 +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));
@ -157,6 +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;
}
}