X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=327d35c4875523188324556b26a32776d02d1bd6;hb=8c1756ef3fd42cc2f324baf47e13a83f51045efe;hp=c05388145a79f663296d9390a974554fb771c384;hpb=56387d062db4aca0510daa34579aa139570bac87;p=org.ibex.core.git

diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java
index c053881..327d35c 100644
--- a/src/org/xwt/js/JS.java
+++ b/src/org/xwt/js/JS.java
@@ -1,203 +1,172 @@
-// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL] 
+// 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 */
-// FEATURE: try using mutable, recycled 'Num' objects
-public abstract class JS { 
+/**
+ *  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.
+ */
+public class JS { 
 
-    // Static Methods //////////////////////////////////////////////////////////////////////
+    // Public Helper Methods //////////////////////////////////////////////////////////////////////
 
-    public static Function getCurrentFunction() {
-	return (Function)currentFunction.get(Thread.currentThread());
-    }
-    public static String getCurrentFunctionSourceName() {
-	return getCurrentFunctionSourceName(Thread.currentThread());
-    }
-    public static String getCurrentFunctionSourceName(Thread t) {
-	Function f = (Function)currentFunction.get(t);
-	if (f == null) return "null";
-	return f.getSourceName();
-    }
-    public static String getFileAndLine() {
-	return "unknown:??";
+    /** parse and compile a function */
+    public static JSFunction parse(String sourceName, int firstLine, Reader sourceCode) throws IOException {
+        return new JSFunction(sourceName, firstLine, sourceCode, null);
     }
 
+    /** 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();
-	// FIXME
-	throw new Error("toNumber() got object of type " + o.getClass().getName());
+        if (o == null) return new Long(0);
+        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 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 /////////////////////////////////////////////////////////////////////////
-
-    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()); }
-    }
-
+    // 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;
+
+    // FEATURE: be smart here; perhaps intern
+    public static final Number N(int i) { return new Integer(i); }
+    public static final Number N(long l) { return new Long(l); }
+    public static final Number N(double d) { return new Double(d); }
+    public static final Boolean B(boolean b) { return b ? Boolean.TRUE : Boolean.FALSE; }
+    
+    private static Enumeration emptyEnumeration = new Enumeration() {
+            public boolean hasMoreElements() { return false; }
+            public Object nextElement() { throw new NoSuchElementException(); }
+        };
+    
+    private Hash entries = null;
+    public Enumeration keys() { return entries == null ? emptyEnumeration : entries.keys(); }
+    public Object get(Object key) { return entries == null ? null : entries.get(key, null); }
+    public void put(Object key, Object val) { if (entries == null) entries = new Hash(); entries.put(key, null, val); }
+
+    // note that we don't actually implement trappable... we just provide these for subclasses which choose to
+    public JSTrap getTrap(Object key) { return entries == null ? null : (JSTrap)entries.get(key, JSTrap.class); }
+    public void putTrap(Object key, JSTrap t) { if (entries == null) entries = new Hash(); entries.put(key, JSTrap.class, t); }
+
+    public Number coerceToNumber() { throw new JS.Exn("tried to coerce a JavaScript object to a Number"); }
+    public String coerceToString() { throw new JS.Exn("tried to coerce a JavaScript object to a String"); }
+    public boolean coerceToBoolean() { throw new JS.Exn("tried to coerce a JavaScript object to a Boolean"); }
+
+    public String typeName() { return "object"; }
+
+
+    // Inner Classes /////////////////////////////////////////////////////////////////////////
+
+    /** 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.toString(); }
-	public String getMessage() { return toString(); }
-	public Object getObject() { return js; } 
+        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; } 
     } 
 
-    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); }
-    }
-
-    public static Hashtable currentFunction = new Hashtable();
-    public static abstract class Function extends Obj {
-	public abstract Object _call(JS.Array args) throws JS.Exn;
-	public String getSourceName() throws JS.Exn { return "unknown"; }
-	public final Object call(JS.Array args) throws JS.Exn { return _call(args); }
-    }
-
-    public static class Script extends Function {
-	Vector e = null;
-	private Script(Vector e) { this.e = e; }
-	public String getSourceName() throws JS.Exn { return ((ForthBlock)e.elementAt(0)).sourceName; }
-	public Object _call(JS.Array args) throws JS.Exn {
-	    Scope rootScope = (Scope)args.elementAt(0);
-	    Function saved = (Function)currentFunction.get(Thread.currentThread());
-	    currentFunction.put(Thread.currentThread(), this);
-	    try {
-		for(int i=0; i<e.size(); i++)
-		    ((ForthBlock)e.elementAt(i)).eval(rootScope);
-	    } catch (ForthBlock.ReturnException e) {
-		// ignore
-	    } catch (ForthBlock.ControlTransferException e) {
-		throw new JS.Exn("block threw a ControlTransferException: " + e);
-	    } finally {
-		if (saved == null) currentFunction.remove(Thread.currentThread());
-		else currentFunction.put(Thread.currentThread(), saved);
-	    }
-	    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) {
-		    ForthBlock ret = p.parseStatement(false);
-		    if (ret == null) break;
-		    exprs.addElement(ret);
-		}
-		return new Script(exprs);
-	    } catch (Exception e) {
-		if (Log.on) Log.log(Parser.class, e);
-		return null;
-	    }
-	}
+    /** the result of a graft */
+    // FIXME: uber-broken
+    public static class Graft extends JSCallable {
+        private JS graftee;
+        private Object replaced_key;
+        private Object replaced_val;
+        public Graft(Object graftee, Object key, Object val) {
+            if (graftee instanceof JSArray) throw new JS.Exn("can't graft onto JSArrays (yet)");
+            if (graftee instanceof JSCallable) throw new JS.Exn("can't graft onto JSCallables (yet)");
+            if (graftee instanceof JSScope) throw new JS.Exn("can't graft onto JSScopes (yet)");
+            this.graftee = (JS)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 call(Object method, JSArray args) {
+            if (replaced_key.equals(method)) return ((JSCallable)replaced_val).call(null, args);
+            else if (graftee instanceof JSCallable) return ((JSCallable)graftee).call(method, args);
+            else throw new JS.Exn("cannot call this value");
+        }
+        */
+        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 Enumeration keys() {
+            return new Enumeration() {
+                    Enumeration graftee_enumeration = graftee.keys();
+                    boolean returned_replaced = false;
+                    public boolean hasMoreElements() {
+                        if (graftee_enumeration.hasMoreElements()) return true;
+                        return !returned_replaced;
+                    }
+                    public Object nextElement() {
+                        if (!graftee_enumeration.hasMoreElements()) {
+                            if (returned_replaced) throw new NoSuchElementException();
+                            returned_replaced = true;
+                            return replaced_key;
+                        } else {
+                            Object ret = graftee_enumeration.nextElement();
+                            if (!returned_replaced && ret.equals(replaced_key)) returned_replaced = true;
+                            return ret;
+                        }
+                    }
+                };
+        }
     }
-
-    /** 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);}
-    } 
- 
-
 }