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;
+
+ /** 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;
+
+ /** 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 JS unclone();
+ public String coerceToString() throws JSExn;
+
+
+ // 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 JS call(JS method, JS[] args) throws JSExn {
+ if (method == null) throw new JSExn( "object cannot be called, class ["+ getClass().getName() +"]");
+ 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 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 {
+ Log.warn(this, "'" + JSU.str(key) + "' is not trappable on class ["+ getClass().getName() +"]"); }
+ public void delTrap(JS key, JS function) throws JSExn {
+ Log.warn(this, "'" + JSU.str(key) + "' trap is read only on class ["+ getClass().getName() +"]"); }
+ public Trap getTrap(JS key) throws JSExn {
+ //Log.warn(this, "'" + JSU.str(key) + "' is not trappable on class ["+ getClass().getName() +"]");
+ return null;
+ }
+ public String coerceToString() throws JSExn {
+ throw new JSExn("cannot coerce a " + getClass().getName() + " to a string"); }
}
-
- 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 JS call(JS m, JS[] a) throws JSExn { return clonee.call(m, 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() throws JSExn { return clonee.coerceToString(); }
+ }
+
+ public static class Obj extends Basket.HashMap implements JS {
+ private static final String[] emptystr = new String[0];
+ private static final Placeholder holder = new Placeholder();
+
+ public Obj() { super(3, 4, 0.75F); }
+
+ public JS unclone() { return this; }
+
+ public JS call(JS method, JS[] args) throws JSExn {
+ if (method==null) throw new JSExn("cannot call a " + getClass().getName());
+ throw new JSExn("method not found: " + JSU.str(method)); }
+ public String[] getFormalArgs() { return emptystr; }
+
+ public Enumeration keys() throws JSExn {
+ final Object[] keys = super.dumpkeys();
+ return new Enumeration(null) {
+ private int cur = 0;
+ public boolean _hasNext() { return cur < keys.length; }
+ public JS _next() throws JSExn {
+ if (cur >= keys.length) throw new NoSuchElementException();
+ return (JS)keys[cur++];
+ }
+ };
}
- 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 { return (JS)super.get(key, 0); }
+ public void put(JS key, JS val) throws JSExn { super.put(key, val, 0); }
+
+ public JS putAndTriggerTraps(JS key, JS val) throws JSExn {
+ Trap t = (Trap)super.get(key, 1);
+ 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()
+ 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 = (Trap)super.get(key, 1);
+ return t == null ? (JS)super.get(key) : (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 = (Trap)super.get(key, 1);
+ 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: case ByteCodes.CALLMETHOD: get = true; break;
- default: throw new Error("should never happen: i.f.op[i.pc] == " + i.f.op[i.pc]);
+ 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)");
+ for (Trap t = (Trap)super.get(key, 1); t != null; t = t.next())
+ if (t.function().equals(f)) return;
+ super.put(key, new TrapHolder(this, key, f, (Trap)super.get(key, 1)), 1);
}
- 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 {
+ Trap t = (Trap)super.get(key, 1);
+ if (t==null) return;
+ if (t.function().equals(f)) { super.put(key, t.next(), 2); 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 { return (Trap)super.get(key, 1); }
+ public String coerceToString() throws JSExn {
+ throw new JSExn("cannot coerce a " + getClass().getName() + " to a string"); }
- // Static Helper Methods ///////////////////////////////////////////////////////////////////////////////////
+ private static final class Placeholder implements Serializable {}
- /** 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();
+ 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; }
+ public JS key() { return key; }
+ public JS target() { return target; }
+ public JS function() { return function; }
+ 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(); }
}
- if(o instanceof JSString) {
- String s = ((JSString)o).s;
- for(int i=0;i<s.length();i++)
- if(s.charAt(i) < '0' || s.charAt(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());
}
- 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;
- }
- 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 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 static JS cloneWithNewGlobalScope(JS js, JS s) {
- if(js instanceof JSFunction)
- return ((JSFunction)js)._cloneWithNewParentScope(new JSScope.Top(s));
- else
- return js;
+ 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++); }
+ }
+ }
-}
+}