X-Git-Url: http://git.megacz.com/?p=org.ibex.js.git;a=blobdiff_plain;f=src%2Forg%2Fibex%2Fjs%2FJS.java;h=a7270482ea2ed6e323f2abf7ab18ae9d48dc23c2;hp=538fc1aa27d0d0ff80757e2abc53efb78ebb180a;hb=aaf060ff38871512d80f1bbf04a6596648b284c7;hpb=19d66e161db458135518efd3539048f44e1e5622 diff --git a/src/org/ibex/js/JS.java b/src/org/ibex/js/JS.java index 538fc1a..a727048 100644 --- a/src/org/ibex/js/JS.java +++ b/src/org/ibex/js/JS.java @@ -1,4 +1,7 @@ -// Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL] +// Copyright 2000-2005 the Contributors, as shown in the revision logs. +// Licensed under the Apache Public Source License 2.0 ("the License"). +// You may not use this file except in compliance with the License. + package org.ibex.js; import org.ibex.util.*; @@ -6,314 +9,358 @@ import java.io.*; import java.util.*; /** The minimum set of functionality required for objects which are manipulated by JavaScript */ -public abstract class JS { - public static final JS METHOD = new JS() { }; - - public JS.Enumeration keys() throws JSExn { throw new JSExn("you can't enumerate the keys of this object (class=" + getClass().getName() +")"); } - public JS get(JS key) throws JSExn { return null; } - public void put(JS key, JS val) throws JSExn { throw new JSExn("" + key + " is read only (class=" + getClass().getName() +")"); } - - public JS callMethod(JS method, JS a0, JS a1, JS a2, JS[] rest, int nargs) throws JSExn { - throw new JSExn("method not found (" + JS.debugToString(method) + ")"); - } - public JS call(JS a0, JS a1, JS a2, JS[] rest, int nargs) throws JSExn { - throw new JSExn("you cannot call this object (class=" + this.getClass().getName() +")"); - } - public InputStream getInputStream() throws IOException { - throw new IOException("this object doesn't have a stream associated with it " + getClass().getName() + ")"); - } - - public final JS unclone() { return _unclone(); } - public final JS jsclone() throws JSExn { return new Clone(this); } - public final boolean hasTrap(JS key) { return getTrap(key) != null; } - public final boolean equals(Object o) { return this == o || ((o instanceof JS) && jsequals((JS)o)); } - // Discourage people from using toString() - public final String toString() { return "JS Object [class=" + getClass().getName() + "]"; } - - // Package private methods - Trap getTrap(JS key) { return null; } - void putTrap(JS key, Trap value) throws JSExn { throw new JSExn("traps cannot be placed on this object (class=" + this.getClass().getName() +")"); } - String coerceToString() throws JSExn { throw new JSExn("can't coerce to a string (class=" + getClass().getName() +")"); } - boolean jsequals(JS o) { return this == o; } - JS _unclone() { return this; } - - public static class O extends JS implements Cloneable { - private Hash entries; - - public Enumeration keys() throws JSExn { return entries == null ? (Enumeration)EMPTY_ENUMERATION : (Enumeration)new JavaEnumeration(null,entries.keys()); } - public JS get(JS key) throws JSExn { return entries == null ? null : (JS)entries.get(key, null); } - public void put(JS key, JS val) throws JSExn { (entries==null?entries=new Hash():entries).put(key,null,val); } - - /** retrieve a trap from the entries hash */ - final Trap getTrap(JS key) { - return entries == null ? null : (Trap)entries.get(key, Trap.class); +public interface JS extends Pausable { + + /** Returns an enumeration of the keys in this object. */ + public JS.Enumeration keys() throws JSExn; + + /** Return the value associated with the given key. */ + public JS get(JS key) throws JSExn; + + /** Store a specific value against the given key. */ + public void put(JS key, JS value) throws JSExn; + + /** Executes or unpauses the task, running it in a + * pausable context. */ + public Object run(Object o) throws Exception, AlreadyRunningException; + + /** Pauses the running task at its convienience. */ + public void pause() throws NotPausableException; + + /** Calls a specific method with given arguments on this object. + * An exception is thrown if there is no such method or the + * arguments are invalid. */ + public JS call(JS method, JS[] args) throws JSExn; + + /** Calls this object with the given arguments, running it in an + * unpausable context. An exception is thrown if this + * object is not callable or the arguments are invalid. */ + public JS call(JS[] args) throws JSExn; + + /** Returns the names of the formal arguments, if any. + * This function must never return a null object. */ + public String[] getFormalArgs(); + + /** Put a value to the given key, calling any write traps that have + * been placed on the key. + * + * This function may block for an indeterminate amount of time. + * + * Write traps may change the final value before it is put, thus + * be careful to read the latest value from this function's return + * before doing any more work with it. + */ + public JS putAndTriggerTraps(JS key, JS value) throws JSExn; + + /** Gets the value for a given key, calling any read traps that have + * been placed on the key. + * + * This function may block for an indeterminate amount of time. + */ + public JS getAndTriggerTraps(JS key) throws JSExn; + + /** Calls the write traps placed on a given key with the given value + * and returns the result without saving it to this object's key store. */ + public JS justTriggerTraps(JS key, JS value) throws JSExn; + + public void addTrap(JS key, JS function) throws JSExn; + public void delTrap(JS key, JS function) throws JSExn; + public Trap getTrap(JS key) throws JSExn; + + // FIXME: consider renaming/removing these + public InputStream getInputStream() throws IOException, JSExn; + public JS unclone(); + public String coerceToString(); + + + // Implementations //////////////////////////////////////////////////////// + + /** Provides the lightest possible implementation of JS, throwing + * exceptions on every mutable operation. */ + public static class Immutable implements JS { + private static final String[] emptystr = new String[0]; + + public JS unclone() { return this; } + public JS.Enumeration keys() throws JSExn { throw new JSExn( + "object has no key set, class ["+ getClass().getName() +"]"); } + public JS get(JS key) throws JSExn { return null; } + public void put(JS key, JS val) throws JSExn { throw new JSExn( + "'" + key + "' is read only on class ["+ getClass().getName() +"]"); } + public InputStream getInputStream() throws IOException, JSExn { throw new JSExn( + "object has not associated stream, class ["+ getClass().getName() +"]"); } + + public Object run(Object o) throws Exception { throw new JSExn( + "object cannot be called, class ["+ getClass().getName() +"]"); } + public void pause() { throw new NotPausableException(); } + + public JS call(JS[] args) throws JSExn { throw new JSExn( "object cannot be called, class ["+ getClass().getName() +"]"); } + public JS call(JS method, JS[] args) throws JSExn { + if (method == null) return call(args); + throw new JSExn("method not found: " + JSU.str(method) + " class="+this.getClass().getName()); } - - /** retrieve a trap from the entries hash */ - final void putTrap(JS key, Trap value) { - if (entries == null) entries = new Hash(); - entries.put(key, Trap.class, value); - } + public String[] getFormalArgs() { return emptystr; } + + public void declare(JS key) throws JSExn { throw new JSExn( + "object cannot declare key: "+ JSU.str(key)); } + public void undeclare(JS key) throws JSExn { } // FIXME throw error? + + public JS putAndTriggerTraps(JS key, JS val) throws JSExn { throw new JSExn( + "'" + key + "' is trap read only on class ["+ getClass().getName() +"]"); } + public JS getAndTriggerTraps(JS key) throws JSExn { return null; } // FIXME throw errors? + public JS justTriggerTraps(JS key, JS value) throws JSExn { return null; } + + public void addTrap(JS key, JS function) throws JSExn { throw new JSExn( + "'" + key + "' is not trappable on class ["+ getClass().getName() +"]"); } + public void delTrap(JS key, JS function) throws JSExn { throw new JSExn( + "'" + key + "' trap is read only on class ["+ getClass().getName() +"]"); } + public Trap getTrap(JS key) throws JSExn { throw new JSExn( + "'" + key + "' is not trappable on class ["+ getClass().getName() +"]"); } + + public String coerceToString() { return "object"; } } - - public interface Cloneable { } - - public static class Clone extends O { + + public interface Cloneable {} + + public static class Clone implements JS { protected final JS clonee; public Clone(JS clonee) throws JSExn { - if(!(clonee instanceof Cloneable)) throw new JSExn("" + clonee.getClass().getName() + " isn't cloneable"); + if (!(clonee instanceof Cloneable)) throw new JSExn( + clonee.getClass().getName() + " is not implement cloneable"); this.clonee = clonee; } - JS _unclone() { return clonee.unclone(); } - boolean jsequals(JS o) { return clonee.jsequals(o); } - + + public JS unclone() { return clonee.unclone(); } + public boolean equals(Object o) { return clonee.equals(o); } + public Enumeration keys() throws JSExn { return clonee.keys(); } - public final JS get(JS key) throws JSExn { return clonee.get(key); } - public final void put(JS key, JS val) throws JSExn { clonee.put(key,val); } - public final JS callMethod(JS method, JS a0, JS a1, JS a2, JS[] rest, int nargs) throws JSExn { - return clonee.callMethod(method,a0,a1,a2,rest,nargs); + public JS get(JS k) throws JSExn { return clonee.get(k); } + public void put(JS k, JS v) throws JSExn { clonee.put(k, v); } + public InputStream getInputStream() throws IOException, JSExn { + return clonee.getInputStream(); } + + public Object run(Object o) throws Exception { return clonee.run(o); } + public void pause() { clonee.pause(); } + + public JS call(JS m, JS[] a) throws JSExn { return clonee.call(m, a); } + public JS call(JS[] a) throws JSExn { return clonee.call(a); } + public String[] getFormalArgs() { return clonee.getFormalArgs(); } + + public JS putAndTriggerTraps(JS k, JS v) throws JSExn { + return clonee.putAndTriggerTraps(k, v); } + public JS getAndTriggerTraps(JS k) throws JSExn { + return clonee.getAndTriggerTraps(k); } + public JS justTriggerTraps(JS k, JS v) throws JSExn { + return clonee.justTriggerTraps(k, v); } + + public void addTrap(JS k, JS f) throws JSExn { clonee.addTrap(k, f); } + public void delTrap(JS k, JS f) throws JSExn { clonee.delTrap(k, f); } + public Trap getTrap(JS k) throws JSExn { return clonee.getTrap(k); } + + public String coerceToString() { return clonee.coerceToString(); } + } + + public static class Obj extends Basket.Hash implements JS { + private static final String[] emptystr = new String[0]; + private static final Placeholder holder = new Placeholder(); + + // HACK: this is hideously, disgustingly ugly.... we need N-ary Hash classes + /** entries[index + 0] // key + * entries[index + 1] // value + * entries[index + 2] // trap + */ + + protected void entryAdded(int p) {} + protected void entryUpdated(int p) {} + protected void entryRemoved(int p) {} + + public Obj() { super(3, 4, 0.75F); } + + public JS unclone() { return this; } + public InputStream getInputStream() throws IOException, JSExn { throw new JSExn( + "object has not associated stream, class ["+ getClass().getName() +"]"); } + + public Object run(Object o) throws Exception { throw new JSExn( + "object cannot be called, class ["+ getClass().getName() +"]"); } + public void pause() { throw new NotPausableException(); } + + public JS call(JS[] args) throws JSExn { throw new JSExn( + "object cannot be called, class ["+ getClass().getName() +"]"); } + public JS call(JS method, JS[] args) throws JSExn { throw new JSExn( + "method not found: " + JSU.str(method)); } + public String[] getFormalArgs() { return emptystr; } + + public Enumeration keys() throws JSExn { + return new Enumeration(null) { + private int dest = -1, next = -1; + public boolean _hasNext() { + for (int i = Math.max(0, dest); i < usedslots; i++) + if (i > 0 ? entries[i * indexmultiple] != null : true && + entries[i * indexmultiple] != this) { next = i; return true; } + return false; + } + public JS _next() throws JSExn { + if (next < 0 && !hasNext()) throw new NoSuchElementException(); + int index = next; dest = next; next = -1; + return (JS)entries[index * indexmultiple]; + } + }; } - public JS call(JS a0, JS a1, JS a2, JS[] rest, int nargs) throws JSExn { - return clonee.call(a0, a1, a2, rest, nargs); + public JS get(JS key) throws JSExn { int i = indexOf(key); + return i < 0 ? null : entries[i + 1] instanceof Placeholder ? null : (JS)entries[i + 1]; } + public void put(JS key, JS val) throws JSExn { + // NOTE: only way value can be stored as null is using declare() + int dest = put(indexOf(key), key); + if (val == null) entries[dest + 1] = holder; + else entries[dest + 1] = val; } + + /*public boolean hasValue(JS key, JS value) { + int i = indexOf(key); return i >= 0 && entries[i + 1] != null; } + public boolean hasTrap(JS key, JS trap) { + int i = indexOf(key); return i >= 0 && entries[i + 2] != null; }*/ + + public void declare(JS key) throws JSExn { entries[put(indexOf(key), key) + 1] = null; } + public void undeclare(JS key) throws JSExn { remove(indexOf(key)); } + + public JS putAndTriggerTraps(JS key, JS val) throws JSExn { + Trap t = null; int i = indexOf(key); + if (i >= 0) t = (Trap)entries[i + 2]; + if (t != null && (t = t.write()) != null) { + val = (JS)new Interpreter(t, val, false).run(null); + } + put(key, val); // HACK: necessary for subclasses overriding put() + /*if (i < 0) i = put(i, key); + if (val == null) entries[i + 1] = holder; + else entries[i + 1] = val;*/ + return val; } - public InputStream getInputStream() throws IOException { return clonee.getInputStream(); } - // FIXME: This shouldn't be necessary (its for Ibex.Blessing) - public JS getClonee() { return clonee; } - } - - public static abstract class Enumeration extends JS { - final Enumeration parent; - boolean done; - public Enumeration(Enumeration parent) { this.parent = parent; } - protected abstract boolean _hasMoreElements(); - protected abstract JS _nextElement() throws JSExn; - - public final boolean hasMoreElements() { - if(!done && !_hasMoreElements()) done = true; - return !done ? true : parent != null ? parent.hasMoreElements() : false; + public JS getAndTriggerTraps(JS key) throws JSExn { + Trap t = null; int i = indexOf(key); + if (i < 0) return get(key); // HACK: necessary for subclasses overriding get() + t = (Trap)entries[i + 2]; + return t == null ? (JS)entries[i + 1] : (JS)new Interpreter(t, null, false).run(null); } - public final JS nextElement() throws JSExn { return !done ? _nextElement() : parent != null ? parent.nextElement() : null; } - - public JS get(JS key) throws JSExn { - //#switch(JS.toString(key)) - case "hasMoreElements": return B(hasMoreElements()); - case "nextElement": return nextElement(); - //#end - return super.get(key); + public JS justTriggerTraps(JS key, JS val) throws JSExn { + Trap t = null; int i = indexOf(key); + if (i >= 0) t = (Trap)entries[i + 2]; + if (t == null || (t = t.write()) == null) return val; + return (JS)new Interpreter(t, val, true).run(null); } - } - public static class EmptyEnumeration extends Enumeration { - public EmptyEnumeration(Enumeration parent) { super(parent); } - protected boolean _hasMoreElements() { return false; } - protected JS _nextElement() { return null; } - } - public static class JavaEnumeration extends Enumeration { - private final java.util.Enumeration e; - public JavaEnumeration(Enumeration parent, java.util.Enumeration e) { super(parent); this.e = e; } - protected boolean _hasMoreElements() { return e.hasMoreElements(); } - protected JS _nextElement() { return (JS) e.nextElement(); } - } - - // Static Interpreter Control Methods /////////////////////////////////////////////////////////////// - - /** log a message with the current JavaScript sourceName/line */ - public static void log(Object message) { info(message); } - public static void debug(Object message) { Log.debug(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); } - public static void info(Object message) { Log.info(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); } - public static void warn(Object message) { Log.warn(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); } - public static void error(Object message) { Log.error(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); } - - 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(); - boolean get; - switch(i.f.op[i.pc]) { - case Tokens.RETURN: case ByteCodes.PUT: get = false; break; - case ByteCodes.GET: case ByteCodes.CALL: get = true; break; - default: throw new Error("should never happen"); + public void addTrap(JS key, JS f) throws JSExn { + if (f.getFormalArgs() == null || f.getFormalArgs().length > 1) throw new JSExn( + "traps must take either one argument (write) or no arguments (read)"); + int i = indexOf(key); if (i < 0) i = put(i, key); + for (Trap t = (Trap)entries[i + 2]; t != null; t = t.next()) + if (t.function().equals(f)) return; + entries[i + 2] = new TrapHolder(this, key, f, (Trap)entries[i + 2]); } - i.pausecount++; - return new JS.UnpauseCallback(i,get); - } - public static class UnpauseCallback implements Task { - private Interpreter i; - private boolean get; - UnpauseCallback(Interpreter i, boolean get) { this.i = i; this.get = get; } - public void perform() throws JSExn { unpause(); } - public JS unpause() throws JSExn { return unpause((JS)null); } - public JS unpause(JS o) throws JSExn { - if (o == JS.METHOD) throw new JSExn("can't return a method to a paused context"); - if(get) i.stack.push(o); - return i.resume(); + public void delTrap(JS key, JS f) throws JSExn { + int i = indexOf(key); if (i < 0) return; + Trap t = (Trap)entries[i + 2]; + if (t.function().equals(f)) { entries[i + 2] = t.next(); return; } + for (; t.next() != null; t = t.next()) + if (t.next().function().equals(f)) { ((TrapHolder)t).next = t.next().next(); return; } } - public JS unpause(JSExn e) throws JSExn { - i.catchException(e); - return i.resume(); + + public Trap getTrap(JS key) throws JSExn { + int i = indexOf(key); return i < 0 ? null : (Trap)entries[i + 2]; } - } + public String coerceToString() { return "object"; } + private static final class Placeholder implements Serializable {} - // Static Helper Methods /////////////////////////////////////////////////////////////////////////////////// + private static final class TrapHolder implements Trap { + private final JS target, key, function; + private Trap next; + TrapHolder(JS t, JS k, JS f, Trap n) { target = t; key = k; function = f; next = n; } - /** coerce an object to a Boolean */ - public static boolean toBoolean(JS o) { - if(o == null) return false; - if(o instanceof JSNumber) return ((JSNumber)o).toBoolean(); - if(o instanceof JSString) return ((JSString)o).s.length() != 0; - return true; - } - //#repeat long/int/double/float toLong/toInt/toDouble/toFloat Long/Integer/Double/Float parseLong/parseInt/parseDouble/parseFloat - /** coerce an object to a Number */ - public static long toLong(JS o) throws JSExn { - if(o == null) return 0; - if(o instanceof JSNumber) return ((JSNumber)o).toLong(); - if(o instanceof JSString) return Long.parseLong(o.coerceToString()); - throw new JSExn("can't coerce a " + o.getClass().getName() + " to a number"); - } - //#end - - public static String toString(JS o) throws JSExn { - if(o == null) return "null"; - return o.coerceToString(); - } - - public static String debugToString(JS o) { - try { return toString(o); } - catch(JSExn e) { return o.toString(); } - } - - public static boolean isInt(JS o) { - if(o == null) return true; - if(o instanceof JSNumber.I) return true; - if(o instanceof JSNumber.B) return false; - if(o instanceof JSNumber) { - JSNumber n = (JSNumber) o; - return n.toInt() == n.toDouble(); - } - if(o instanceof JSString) { - String s = ((JSString)o).s; - for(int i=0;i '9') return false; - return true; - } - return false; - } - - public static boolean isString(JS o) { - if(o instanceof JSString) return true; - return false; - } - - // Instance Methods //////////////////////////////////////////////////////////////////// - - public final static JS NaN = new JSNumber.D(Double.NaN); - public final static JS ZERO = new JSNumber.I(0); - public final static JS ONE = new JSNumber.I(1); - public final static JS MATH = new JSMath(); - - public static final JS T = new JSNumber.B(true); - public static final JS F = new JSNumber.B(false); - - public static final JS B(boolean b) { return b ? T : F; } - public static final JS B(int i) { return i==0 ? F : T; } - - private static final int CACHE_SIZE = 65536 / 4; // must be a power of two - private static final JSString[] stringCache = new JSString[CACHE_SIZE]; - public static final JS S(String s) { - if(s == null) return null; - int slot = s.hashCode()&(CACHE_SIZE-1); - JSString ret = stringCache[slot]; - if(ret == null || !ret.s.equals(s)) stringCache[slot] = ret = new JSString(s); - return ret; - } - public static final JS S(String s, boolean intern) { return intern ? JSString.intern(s) : S(s); } - - public static final JS N(double d) { return new JSNumber.D(d); } - public static final JS N(long l) { return new JSNumber.L(l); } - - public static final JS N(Number n) { - if(n instanceof Integer) return N(n.intValue()); - if(n instanceof Long) return N(n.longValue()); - return N(n.doubleValue()); - } + public JS key() { return key; } + public JS target() { return target; } + public JS function() { return function; } - private static final JSNumber.I[] smallIntCache = new JSNumber.I[CACHE_SIZE]; - private static final JSNumber.I[] largeIntCache = new JSNumber.I[CACHE_SIZE]; - public static final JS N(int i) { - JSNumber.I ret = null; - int idx = i + smallIntCache.length / 2; - if (idx < CACHE_SIZE && idx > 0) { - ret = smallIntCache[idx]; - if (ret != null) return ret; - } - else ret = largeIntCache[Math.abs(idx % CACHE_SIZE)]; - if (ret == null || ret.i != i) { - ret = new JSNumber.I(i); - if (idx < smallIntCache.length && idx > 0) smallIntCache[idx] = ret; - else largeIntCache[Math.abs(idx % CACHE_SIZE)] = ret; + public boolean isReadTrap() { + return function.getFormalArgs() == null || function.getFormalArgs().length == 0; } + public boolean isWriteTrap() { + return function.getFormalArgs() != null && function.getFormalArgs().length != 0; } + + public Trap next() { return next; } + public Trap nextRead() { + Trap t = next; while (t != null && t.isWriteTrap()) t = t.next(); return t; } + public Trap nextWrite() { + Trap t = next; while (t != null && t.isReadTrap()) t = t.next(); return t; } + public Trap read() { return isReadTrap() ? this : nextRead(); } + public Trap write() { return isWriteTrap() ? this : nextWrite(); } } - return ret; - } - - private static Enumeration EMPTY_ENUMERATION = new EmptyEnumeration(null); - - public static JS fromReader(String sourceName, int firstLine, Reader sourceCode) throws IOException { - return Parser.fromReader(sourceName, firstLine, sourceCode); } - public static JS cloneWithNewGlobalScope(JS js, JS s) { - if(js instanceof JSFunction) - return ((JSFunction)js)._cloneWithNewParentScope(new JSScope.Top(s)); - else - return js; + public interface Trap { + public JS key(); + public JS target(); + public JS function(); + public boolean isReadTrap(); + public boolean isWriteTrap(); + public Trap next(); + public Trap nextRead(); + public Trap nextWrite(); + + public Trap read(); // FIXME reconsider these function names + public Trap write(); } + /** An empty class used for instanceof matching the result of JS.get() + * to decide if the key is a method (to be called with JS.callMethod(). */ + public static final class Method extends Immutable {} - // Trap support ////////////////////////////////////////////////////////////////////////////// - /** performs a put, triggering traps if present; traps are run in an unpauseable interpreter */ - public final void putAndTriggerTraps(JS key, JS value) throws JSExn { - Trap t = getTrap(key); - if(t == null || (t = t.writeTrap()) == null) put(key,value); - else new Interpreter(t,value,false).resume(); - } + public static abstract class Enumeration extends Immutable { + public static final Enumeration EMPTY = new Empty(null); - /** performs a get, triggering traps if present; traps are run in an unpauseable interpreter */ - public final JS getAndTriggerTraps(JS key) throws JSExn { - Trap t = getTrap(key); - if (t == null || (t = t.readTrap()) == null) return get(key); - else return new Interpreter(t,null,false).resume(); - } - - public final JS justTriggerTraps(JS key, JS value) throws JSExn { - Trap t = getTrap(key); - if(t == null || (t = t.writeTrap()) == null) return value; - else return new Interpreter(t,value,true).resume(); - } + private final Enumeration parent; - /** adds a trap, avoiding duplicates */ - // FIXME: This shouldn't be public, it is needed for a hack in Template.java - public void addTrap(JS key, JSFunction f) throws JSExn { - if (f.numFormalArgs > 1) throw new JSExn("traps must take either one argument (write) or no arguments (read)"); - boolean isRead = f.numFormalArgs == 0; - for(Trap t = getTrap(key); t != null; t = t.next) if (t.f == f) return; - putTrap(key, new Trap(this, key, f, (Trap)getTrap(key))); - } + public Enumeration(Enumeration parent) { this.parent = parent; } - /** deletes a trap, if present */ - // FIXME: This shouldn't be public, it is needed for a hack in Template.java - public void delTrap(JS key, JSFunction f) throws JSExn { - Trap t = (Trap)getTrap(key); - if (t == null) return; - if (t.f == f) { putTrap(t.target, t.next); return; } - for(; t.next != null; t = t.next) if (t.next.f == f) { t.next = t.next.next; return; } - } + protected abstract boolean _hasNext(); + protected abstract JS _next() throws JSExn; + + public final boolean hasNext() { + return _hasNext() || parent != null ? parent.hasNext() : false; } + public final JS next() throws JSExn { + if (_hasNext()) return _next(); + if (parent == null) throw new NoSuchElementException("reached end of set"); + return parent.next(); + } + public JS get(JS key) throws JSExn { + //#switch(JSU.str(key)) + case "hasNext": return JSU.B(hasNext()); + case "next": return next(); + //#end + return super.get(key); + } + + public static final class Empty extends Enumeration { + public Empty(Enumeration parent) { super(parent); } + protected boolean _hasNext() { return false; } + protected JS _next() { throw new NoSuchElementException(); } + } + + public static final class JavaIterator extends Enumeration { + private final Iterator i; + public JavaIterator(Enumeration parent, Iterator i) { super(parent); this.i = i; } + protected boolean _hasNext() { return i.hasNext(); } + protected JS _next() { return (JS)i.next(); } + } + + public static final class RandomAccessList extends Enumeration { + private final List l; + private int pos = 0, size; + public RandomAccessList(Enumeration parent, List list) { + super(parent); l = list; size = l.size(); } + protected boolean _hasNext() { return pos < size; } + protected JS _next() { return (JS)l.get(pos++); } + } + } -} +}