X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=c6d5dd6b0a97ad0ca1f985882083b16facdb5933;hb=6261c41b2ac9d182d8c3541e8e0e5fd00062fa43;hp=256c33a6ee36a74a966343e2bf779d3ead76d05e;hpb=190e32962a4936670125a38c266f81adc098b539;p=org.ibex.core.git diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java index 256c33a..c6d5dd6 100644 --- a/src/org/xwt/js/JS.java +++ b/src/org/xwt/js/JS.java @@ -1,28 +1,55 @@ // Copyright 2003 Adam Megacz, see the COPYING file for licensing [GPL] - package org.xwt.js; + import org.xwt.util.*; +import org.xwt.*; import java.io.*; import java.util.*; -/** - * The public API for the JS engine. JS itself is actually a class - * implementing the absolute minimal amount of functionality for an - * Object which can be manipulated by JavaScript code. The static - * methods, fields, and inner classes of JS define the publicly - * visible API for the XWT JavaScript engine; code outside this - * package should never depend on anything not defined in this file. - */ -public abstract class JS { +/** The minimum set of functionality required for objects which are manipulated by JavaScript */ +public class JS extends org.xwt.util.BalancedTree { + // Static Interpreter Control Methods /////////////////////////////////////////////////////////////// - // Public Helper Methods ////////////////////////////////////////////////////////////////////// + /** log a message with the current JavaScript sourceName/line */ + public static void log(Object o, Object message) { log(message); } + public static void log(Object message) { Log.echo(JS.getSourceName() + ":" + JS.getLine(), message); } - /** parse and compile a function */ - public static CompiledFunction parse(String sourceName, int firstLine, Reader sourceCode) throws IOException { - return new CompiledFunction(sourceName, firstLine, sourceCode, null); + public static int getLine() { + Interpreter c = Interpreter.current(); + return c == null || c.f == null || c.pc < 0 || c.pc >= c.f.size ? -1 : c.f.line[c.pc]; } + public static String getSourceName() { + Interpreter c = Interpreter.current(); + return c == null || c.f == null ? null : c.f.sourceName; + } + + public static class NotPauseableException extends Exception { NotPauseableException() { } } + + /** returns a callback which will restart the context; expects a value to be pushed onto the stack when unpaused */ + public static UnpauseCallback pause() throws NotPauseableException { + Interpreter i = Interpreter.current(); + if (i.pausecount == -1) throw new NotPauseableException(); + i.pausecount++; + return new JS.UnpauseCallback(i); + } + + public static class UnpauseCallback implements Scheduler.Task { + Interpreter i; + UnpauseCallback(Interpreter i) { this.i = i; } + public void perform() throws JSExn { unpause(null); } + public void unpause(Object o) throws JSExn { + // FIXME: if o instanceof JSExn, throw it into the JSworld + i.stack.push(o); + i.resume(); + } + } + + + + // Static Helper Methods /////////////////////////////////////////////////////////////////////////////////// + /** coerce an object to a Boolean */ public static boolean toBoolean(Object o) { if (o == null) return false; @@ -49,17 +76,18 @@ public abstract class JS { /** coerce an object to a Number */ public static Number toNumber(Object o) { - if (o == null) return new Long(0); + if (o == null) return ZERO; if (o instanceof Number) return ((Number)o); // NOTE: There are about 3 pages of rules in ecma262 about string to number conversions // We aren't even close to following all those rules. We probably never will be. - if (o instanceof String) try { return new Double((String)o); } catch (NumberFormatException e) { return new Double(Double.NaN); } - if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? new Long(1) : new Long(0); + if (o instanceof String) + try { return N((String)o); } catch (NumberFormatException e) { return N(Double.NaN); } + if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? N(1) : ZERO; if (o instanceof JS) return ((JS)o).coerceToNumber(); throw new Error("toNumber() got object of type " + o.getClass().getName() + " which we don't know how to handle"); } - + /** coerce an object to a String */ public static String toString(Object o) { if(o == null) return "null"; @@ -73,186 +101,124 @@ public abstract class JS { } return o.toString(); } + // Instance Methods //////////////////////////////////////////////////////////////////// + + public static final Integer ZERO = new Integer(0); - public abstract Object get(Object key) throws JS.Exn; - public abstract void put(Object key, Object val) throws JS.Exn; - public abstract Object[] keys(); - public Object callMethod(Object method, Array args, boolean checkOnly) throws JS.Exn { - if(checkOnly) return Boolean.FALSE; - Object o = get(method); - if(o instanceof JS.Callable) { - return ((JS.Callable)o).call(args); - } else if(o == null) { - throw new JS.Exn("Attempted to call non-existent method: " + method); - } else { - throw new JS.Exn("Attempted to call a non-method: " +method); - } + // this gets around a wierd fluke in the Java type checking rules for ?..: + public static final Object T = Boolean.TRUE; + public static final Object F = Boolean.FALSE; + + public static final Boolean B(boolean b) { return b ? Boolean.TRUE : Boolean.FALSE; } + public static final Boolean B(int i) { return i==0 ? Boolean.FALSE : Boolean.TRUE; } + public static final Number N(String s) { return s.indexOf('.') == -1 ? N(Integer.parseInt(s)) : new Double(s); } + public static final Number N(double d) { return (int)d == d ? N((int)d) : new Double(d); } + public static final Number N(long l) { return N((int)l); } + + private static final Integer[] smallIntCache = new Integer[65535 / 4]; + private static final Integer[] largeIntCache = new Integer[65535 / 4]; + public static final Number N(int i) { + Integer ret = null; + int idx = i + smallIntCache.length / 2; + if (idx < smallIntCache.length && idx > 0) { + ret = smallIntCache[idx]; + if (ret != null) return ret; + } + else ret = largeIntCache[Math.abs(idx % largeIntCache.length)]; + if (ret == null || ret.intValue() != i) { + ret = new Integer(i); + if (idx < smallIntCache.length && idx > 0) smallIntCache[idx] = ret; + else largeIntCache[Math.abs(idx % largeIntCache.length)] = ret; + } + return ret; } - public Number coerceToNumber() { return new Integer(0); } - public String coerceToString() { throw new JS.Exn("tried to coerce a JavaScript object to a String"); } - public boolean coerceToBoolean() { return true; } + private static Enumeration emptyEnumeration = new Enumeration() { + public boolean hasMoreElements() { return false; } + public Object nextElement() { throw new NoSuchElementException(); } + }; - public String typeName() { return "object"; } + private Hash entries = null; + public Enumeration keys() throws JSExn { + return entries == null ? emptyEnumeration : entries.keys(); + } + public Object get(Object key) throws JSExn { return entries == null ? null : entries.get(key, null); } + public void put(Object key, Object val) throws JSExn { + if (entries == null) entries = new Hash(); + entries.put(key, null, val); + } - // Inner Classes ///////////////////////////////////////////////////////////////////////// - - /** A sensible implementation of the abstract methods in the JS class */ - public static class Obj extends JS { - private Hash entries = null; - private boolean sealed = false; - public Obj() { this(false); } - public Obj(boolean sealed) { this.sealed = sealed; } - public void setSeal(boolean sealed) { this.sealed = sealed; } ///< a sealed object cannot have its properties modified - public void put(Object key, Object val) { put(key, null, val); } - protected void put(Object key, Object key2, Object val) { - if (sealed) return; - if (entries == null) entries = new Hash(); - entries.put(key, key2, val); } - public Object[] keys() { return entries == null ? new Object[0] : entries.keys(); } - public Object get(Object key) { return get(key, null); } - protected Object get(Object key, Object key2) { - if (entries == null) return null; - if(key2 == null && callMethod((String)key, null, true) == Boolean.TRUE) - return new Internal.CallableStub(this, key); - return entries.get(key, key2); - } - } + // Trap support ////////////////////////////////////////////////////////////////////////////// - /** An exception which can be thrown and caught by JavaScript code */ - public static class Exn extends RuntimeException { - private Object js = null; - public Exn(Object js) { this.js = js; } - public String toString() { return "JS.Exn: " + js; } - public String getMessage() { return toString(); } - public Object getObject() { return js; } - } + /** override and return true to allow placing traps on this object. + * if isRead true, this is a read trap, otherwise write trap + **/ + protected boolean isTrappable(Object name, boolean isRead) { return false; } - /** The publicly-visible face of JavaScript Array objects */ - public static class Array extends ArrayImpl { - public Array() { } - public Array(int size) { super(size); } - public void setSize(int i) { super.setSize(i); } - public int length() { return super.length(); } - public Object elementAt(int i) { return super.elementAt(i); } - public void addElement(Object o) { super.addElement(o); } - public void setElementAt(Object o, int i) { super.setElementAt(o, i); } - public Object get(Object key) { return super._get(key); } - public void put(Object key, Object val) { super._put(key, val); } + /** performs a put, triggering traps if present; traps are run in an unpauseable interpreter */ + public void putAndTriggerTraps(Object key, Object value) throws JSExn { + Trap t = getTrap(key); + if (t != null) t.invoke(value); + else put(key, value); } - /** Any object which becomes part of the scope chain must support this interface */ - public static class Scope extends ScopeImpl { - public Scope(Scope parentScope) { this(parentScope, false); } - public Scope(Scope parentScope, boolean sealed) { super(parentScope, sealed); } - /** transparent scopes are not returned by THIS */ - public boolean isTransparent() { return super.isTransparent(); } - public boolean has(Object key) { return super.has(key); } - public Object get(Object key) { return super._get(key); } - public void put(Object key, Object val) { super._put(key, val); } - public void declare(String s) { super.declare(s); } - } + /** performs a get, triggering traps if present; traps are run in an unpauseable interpreter */ + public Object getAndTriggerTraps(Object key) throws JSExn { + Trap t = getTrap(key); + if (t != null) return t.invoke(); + else return get(key); + } - /** the result of a graft */ - public static class Graft extends JS { - private JS graftee; - private Object replaced_key; - private Object replaced_val; - public Graft(JS graftee, Object key, Object val) { - if (graftee instanceof Array) throw new JS.Exn("can't graft onto Arrays (yet)"); - if (graftee instanceof Callable) throw new JS.Exn("can't graft onto Callables (yet)"); - if (graftee instanceof Scope) throw new JS.Exn("can't graft onto Scopes (yet)"); - this.graftee = graftee; - replaced_key = key; - replaced_val = val; - } - public boolean equals(Object o) { return (this == o || graftee.equals(o)); } - public int hashCode() { return graftee.hashCode(); } - public Object get(Object key) { return replaced_key.equals(key) ? replaced_val : graftee.get(key); } - public void put(Object key, Object val) { graftee.put(key, val); } - public Object callMethod(Object method, Array args, boolean checkOnly) throws JS.Exn { - if (!replaced_key.equals(method)) return graftee.callMethod(method, args, checkOnly); - if (replaced_val instanceof Callable) return checkOnly ? Boolean.TRUE : ((Callable)replaced_val).call(args); - if (checkOnly) return Boolean.FALSE; - throw new JS.Exn("attempt to call non-function"); - } - public Number coerceToNumber() { return graftee.coerceToNumber(); } - public String coerceToString() { return graftee.coerceToString(); } - public boolean coerceToBoolean() { return graftee.coerceToBoolean(); } - public String typeName() { return graftee.typeName(); } - public Object[] keys() { - Object[] ret = graftee.keys(); - for(int i=0; i 1) throw new JSExn("traps must take either one argument (write) or no arguments (read)"); + boolean isRead = f.numFormalArgs == 0; + if (!isTrappable(name, isRead)) throw new JSExn("not allowed "+(isRead?"read":"write")+" trap on property: "+name); + for(Trap t = getTrap(name); t != null; t = t.next) if (t.f == f) return; + putTrap(name, new Trap(this, name.toString(), f, (Trap)getTrap(name))); } - - /** a scope that is populated with js objects and functions normally found in the global scope */ - public static class GlobalScope extends GlobalScopeImpl { - public GlobalScope() { this(null); } - public GlobalScope(JS.Scope parent) { super(parent); } + + /** deletes a trap, if present */ + protected final void delTrap(Object name, JSFunction f) { + Trap t = (Trap)getTrap(name); + if (t == null) return; + if (t.f == f) { putTrap(t.name, t.next); return; } + for(; t.next != null; t = t.next) if (t.next.f == f) { t.next = t.next.next; return; } } - public static final JS Math = new org.xwt.js.Math(); - - /** encapsulates a single JavaScript thread; the JS.Thread->java.lang.Thread mapping is 1:1 */ - public static class Thread { - CompiledFunction currentCompiledFunction = null; - Vec stack = new Vec(); - public Scope scope = null; - int pc = 0; - boolean paused = false; + // Call Support ////////////////////////////////////////////////////////////////////////////// - CompiledFunction tailCallFunction = null; - JS.Array tailCallArgs = null; + // return this from get() if the key was actually a method. + public static final Object METHOD = new Object(); + public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn { + throw new JSExn("attempted to call the null value (method "+method+")"); + } + public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn { + throw new JSExn("you cannot call this object (class=" + this.getClass().getName() +")"); + } - public Thread(CompiledFunction function) { - this(function, new CompiledFunctionImpl.FunctionScope("unknown", function.parentScope)); - } - public Thread(CompiledFunction function, Scope scope) { - stack.push(new CompiledFunctionImpl.CallMarker(this)); - stack.push(new JS.Array()); - this.currentCompiledFunction = function; - this.scope = scope; - } - public void setTailCall(JS.CompiledFunction f, JS.Array args) { tailCallFunction = f; tailCallArgs = args; } + // Typing Support ////////////////////////////////////////////////////////////////////////////// - public static JS.Thread current() { return (JS.Thread)javaThreadToJSThread.get(java.lang.Thread.currentThread()); } + public Number coerceToNumber() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a Number"); } + public String coerceToString() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a String"); } + public boolean coerceToBoolean() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a Boolean"); } - public void resume() { bind(); paused = false; CompiledFunctionImpl.eval(this); } - public void pause() { paused = true; unbind(); } - public void bind() { javaThreadToJSThread.put(java.lang.Thread.currentThread(), this); } - public void unbind() { if (current() == this) javaThreadToJSThread.put(java.lang.Thread.currentThread(), this); } - public int getLine() { return currentCompiledFunction == null ? -1 : currentCompiledFunction.getLine(this); } - public String getSourceName() { return currentCompiledFunction == null ? null : currentCompiledFunction.getSourceName(); } + public String typeName() { return "object"; } - /** fetches the currently-executing javascript function */ - public JS.CompiledFunction getCurrentCompiledFunction() { return currentCompiledFunction; } - private static Hashtable javaThreadToJSThread = new Hashtable(); - } } - - - -