X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=0336e2712cfc14f77136e5181d606608ee5cc346;hb=772b947b9b23de711953d0a1e33cef5f356c442a;hp=6c9448dfa41a9230104d6e177fc378f696538fe8;hpb=6076f07a78d5e01a53304b0ae9df97273a0688fe;p=org.ibex.core.git

diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java
index 6c9448d..0336e27 100644
--- a/src/org/xwt/js/JS.java
+++ b/src/org/xwt/js/JS.java
@@ -1,239 +1,231 @@
 // 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 minimal amount of functionality for an Object
- *  which can be manipulated by JavaScript code.
- */
-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 ///////////////////////////////////////////////////////////////
 
-    // Static 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); }
+    public static void log(JSExn e) {
+        Log.echo(e,"JS Exception: " + e.getObject() + "\n" + e.backtrace());
+        Log.echo(e,e);
+    }
 
-    private static Hashtable currentFunction = new Hashtable();
-    public static Function getCurrentFunction() { return (Function)currentFunction.get(Thread.currentThread()); }
-    public static String getCurrentFunctionSourceName() { return getCurrentFunctionSourceName(Thread.currentThread()); }
-    public static String getFileAndLine() { return getCurrentFunctionSourceName() + ":" + getCurrentFunction().getLine(); }
-    public static String getCurrentFunctionSourceName(Thread t) {
-	Function f = (Function)currentFunction.get(t);
-	if (f == null) return "null";
-	return f.getSourceName();
+    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;
-	if (o instanceof Boolean) return ((Boolean)o).booleanValue();
-	if (o instanceof Number) return o.equals(new Integer(0));
-	return true;
+        if (o == null) return false;
+        if (o instanceof Boolean) return ((Boolean)o).booleanValue();
+        if (o instanceof Long) return ((Long)o).longValue() != 0;
+        if (o instanceof Integer) return ((Integer)o).intValue() != 0;
+        if (o instanceof Number) {
+            double d = ((Number) o).doubleValue();
+            // NOTE: d == d is a test for NaN. It should be faster than Double.isNaN()
+            return d != 0.0 && d == d;
+        }
+        if (o instanceof String) return ((String)o).length() != 0;
+        return true;
     }
 
+    /** coerce an object to a Long */
     public static long toLong(Object o) { return toNumber(o).longValue(); }
+
+    /** coerce an object to an Int */
+    public static int toInt(Object o) { return toNumber(o).intValue(); }
+
+    /** coerce an object to a Double */
     public static double toDouble(Object o) { return toNumber(o).doubleValue(); }
+
+    /** coerce an object to a Number */
     public static Number toNumber(Object o) {
-	if (o == null) return new Long(0);
-	if (o instanceof Number) return ((Number)o);
-	if (o instanceof String) try { return new Double((String)o); } catch (NumberFormatException e) { return new Double(0); }
-	if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? new Long(1) : new Long(0);
-	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");
+        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 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";
+        if(o instanceof String) return (String) o;
+        if(o instanceof Integer || o instanceof Long || o instanceof Boolean) return o.toString();
+        if(o instanceof JS) return ((JS)o).coerceToString();
+        if(o instanceof Double || o instanceof Float) {
+            double d = ((Number)o).doubleValue();
+            if((int)d == d) return Integer.toString((int)d);
+            return o.toString();
+        }
+        return o.toString();
+    }
 
+    
     // Instance Methods ////////////////////////////////////////////////////////////////////
- 
-    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 Number coerceToNumber() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a Number"); }
-    public String coerceToString() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a String"); }
-    public boolean coerceToBoolean() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a Boolean"); }
-
-
-    // Subclasses /////////////////////////////////////////////////////////////////////////
-
-    /** A slightly more featureful version of JS */
-    public static class Obj extends JS {
-	private Hash entries = new Hash();
-	private boolean sealed = false;
-	public Obj() { this(false); }
-	public Obj(boolean sealed) { this.sealed = sealed; }
-	public void setSeal(boolean sealed) { this.sealed = sealed; }
-	public Object get(Object key) { return entries.get(key); }
-	public void put(Object key, Object val) { if (!sealed) entries.put(key, val); }
-	public Object[] keys() { return(entries.keys()); }
-    }
-
-    /** An exception which can be thrown and caught by JavaScripts */
-    public static class Exn extends RuntimeException { 
-	private Object js = null; 
-	public Exn(Object js) { this.js = js; } 
-	public String toString() { return "JS.Exn: " + js.toString(); }
-	public String getMessage() { return toString(); }
-	public Object getObject() { return js; } 
-    } 
 
-    /** A JavaScript Array */
-    public static class Array extends Obj {
-	private Vec vec = new Vec();
-	public Array() { }
-	public Array(int size) { vec.setSize(size); }
-	private static int intVal(Object o) {
-	    if (o instanceof Number) {
-		int intVal = ((Number)o).intValue();
-		if (intVal == ((Number)o).doubleValue()) return intVal;
-		return Integer.MIN_VALUE;
-	    }
-	    if (!(o instanceof String)) return Integer.MIN_VALUE;
-	    String s = (String)o;
-	    for(int i=0; i<s.length(); i++) if (s.charAt(i) < '0' || s.charAt(i) > '9') return Integer.MIN_VALUE;
-	    return Integer.parseInt(s);
-	}
-	public Object get(Object key) throws JS.Exn {
-	    // FIXME: HACK!
-	    if (key.equals("cascade")) return org.xwt.Trap.cascadeFunction;
-	    if (key.equals("trapee")) return org.xwt.Trap.currentTrapee();
-	    if (key.equals("length")) return new Long(vec.size());
-	    int i = intVal(key);
-	    if (i == Integer.MIN_VALUE) return super.get(key);
-	    try {
-		return vec.elementAt(i);
-	    } catch (ArrayIndexOutOfBoundsException e) {
-		throw new JS.Exn(e.getMessage());
-	    }
-	}
-	public void put(Object key, Object val) {
-	    if (key.equals("length")) vec.setSize(toNumber(val).intValue());
-	    int i = intVal(key);
-	    if (i == Integer.MIN_VALUE) super.put(key, val);
-	    else {
-		if (i >= vec.size()) vec.setSize(i+1);
-		vec.setElementAt(val, i);
-	    }
-	}
-	public Object[] keys() {
-	    Object[] sup = super.keys();
-	    Object[] ret = new Object[vec.size() + 1 + sup.length];
-	    System.arraycopy(sup, 0, ret, vec.size(), sup.length);
-	    for(int i=0; i<vec.size(); i++) ret[i] = new Integer(i);
-	    ret[vec.size()] = "length";
-	    return ret;
-	}
-	public void setSize(int i) { vec.setSize(i); }
-	public int length() { return vec.size(); }
-	public Object elementAt(int i) { return vec.elementAt(i); }
-	public void addElement(Object o) { vec.addElement(o); }
-	public void setElementAt(Object o, int i) { vec.setElementAt(o, i); }
-    }
-
-    /** Anything that is callable */
-    public static class Function extends Obj {
-	ByteCodeBlock bytecodes;
-	int line;
-	String sourceName;
-	Scope parentScope;
-	public Function() { this(-1, "unknown", null, null); }
-	public Function(int line, String sourceName, ByteCodeBlock bytecodes, Scope parentScope) {
-	    this.sourceName = sourceName;
-	    this.line = line;
-	    this.bytecodes = bytecodes;
-	    this.parentScope = parentScope;
-	}
-	public String getSourceName() throws JS.Exn { return sourceName; }
-	public int getLine() throws JS.Exn { return line; }
-	public Object _call(JS.Array args) throws JS.Exn, ByteCodeBlock.ControlTransferException {
-	    if (bytecodes == null) throw new Error("tried to call() a JS.Function with bytecodes == null");
-	    Vec stack = new Vec();
-	    stack.push(args);
-	    return bytecodes.eval(new FunctionScope(sourceName, parentScope), stack);
-	}
-	public final Object call(JS.Array args) throws JS.Exn {
-	    Function saved = (Function)currentFunction.get(Thread.currentThread());
-	    currentFunction.put(Thread.currentThread(), this);
-	    try {
-		return _call(args);
-	    } catch (ByteCodeBlock.ReturnException e) {  // ignore
-		return e.retval;
-	    } catch (ByteCodeBlock.ControlTransferException e) {
-		throw new RuntimeException(getSourceName() + ":" + getLine() +
-					   " error, ControlTransferException tried to leave a function");
-	    } finally {
-		if (saved == null) currentFunction.remove(Thread.currentThread());
-		else currentFunction.put(Thread.currentThread(), saved);
-	    }
-	}
-    }
-
-    public static class Script extends Function {
-	Vector e = null;
-	private Script(Vector e) { this.e = e; }
-	public String getSourceName() throws JS.Exn { return ((ByteCodeBlock)e.elementAt(0)).getSourceName(); }
-	public Object _call(JS.Array args) throws JS.Exn, ByteCodeBlock.ControlTransferException {
-	    Scope rootScope = (Scope)args.elementAt(0);
-	    for(int i=0; i<e.size(); i++) ((ByteCodeBlock)e.elementAt(i)).eval(rootScope, new Vec());
-	    return null;
-	}
-	public static Script parse(Reader r, String sourceName, int line) throws IOException {
-	    Parser p = new Parser(r, sourceName, line);
-	    try {
-		Vector exprs = new Vector();
-		while(true) {
-		    ByteCodeBlock ret = p.parseStatement();
-		    if (ret == null) break;
-		    exprs.addElement(ret);
-		}
-		return new Script(exprs);
-	    } catch (Exception e) {
-		if (Log.on) Log.log(Parser.class, e);
-		return null;
-	    }
-	}
-    }
-
-    /** Any object which becomes part of the scope chain must support this interface */ 
-    public static class Scope extends Obj { 
-	private Scope parentScope;
-	private static Object NULL = new Object();
-	public Scope(Scope parentScope) { this(parentScope, false); }
-	public Scope(Scope parentScope, boolean sealed) { super(sealed); this.parentScope = parentScope; }
-	public Scope getParentScope() { return parentScope; }
-
-	// transparent scopes are not returned by THIS
-	public boolean isTransparent() { return false; }
-
-	public boolean has(Object key) { return super.get(key) != null; }
-	public Object get(Object key) {
-	    if (!has(key)) return parentScope == null ? null : getParentScope().get(key);
-	    Object ret = super.get(key); return ret == NULL ? null : ret;
-	}
-	public void put(Object key, Object val) {
-	    if (!has(key) && parentScope != null) getParentScope().put(key, val);
-	    else super.put(key, val == null ? NULL : val);
-	}
-	public Object[] keys() { throw new Error("you can't enumerate the properties of a Scope"); }
-	public void declare(String s) {
-	    if (isTransparent()) getParentScope().declare(s);
-	    else super.put(s, NULL);
-	}
-    } 
+    public static final Integer ZERO = new Integer(0);
  
-    private class FunctionScope extends JS.Scope {
-	String sourceName;
-	public FunctionScope(String sourceName, Scope parentScope) { super(parentScope); this.sourceName = sourceName; }
-	public String getSourceName() { return sourceName; }
-	public Object get(Object key) throws JS.Exn {
-	    if (key.equals("trapee")) return org.xwt.Trap.currentTrapee();
-	    else if (key.equals("cascade")) return org.xwt.Trap.cascadeFunction;
-	    return super.get(key);
-	}
+    // 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;
+    }
+    
+    private static Enumeration emptyEnumeration = new Enumeration() {
+            public boolean hasMoreElements() { return false; }
+            public Object nextElement() { throw new NoSuchElementException(); }
+        };
+    
+    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);
+    }
+
+
+    // Trap support //////////////////////////////////////////////////////////////////////////////
+
+    /** 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 true; }
+
+    /** 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);
+    }
+
+    /** 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);
+    }
+
+    /** retrieve a trap from the entries hash */
+    protected final Trap getTrap(Object key) {
+        return entries == null ? null : (Trap)entries.get(key, Trap.class);
+    }
+
+    /** retrieve a trap from the entries hash */
+    protected final void putTrap(Object key, Trap value) {
+        if (entries == null) entries = new Hash();
+        entries.put(key, Trap.class, value);
+    }
+
+    /** adds a trap, avoiding duplicates */
+    protected final void addTrap(Object name, 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;
+        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)));
+    }
+
+    /** 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; }
     }
-} 
 
 
+    // Call Support //////////////////////////////////////////////////////////////////////////////
 
+    // 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() +")");
+    }
 
+
+    // Typing Support //////////////////////////////////////////////////////////////////////////////
+
+    public Number coerceToNumber() { throw new JSRuntimeExn("tried to coerce a JavaScript object of type " + 
+                                                            getClass().getName() + " to a Number"); }
+    public String coerceToString() { throw new JSRuntimeExn("tried to coerce a JavaScript object of type " +
+                                                            getClass().getName() + " to a String"); }
+    public boolean coerceToBoolean() { throw new JSRuntimeExn("tried to coerce a JavaScript object of type " +
+                                                            getClass().getName() + " to a Boolean"); }
+
+    public String typeName() { return "object"; }
+
+}