X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=363225024de0de4d13f9a036c106a161520a2fa2;hb=3d545db9c5a99535462adc62cbf9fc88d3dd619b;hp=6e805112ae76d1eb525bf9efa657e8a4cad5789c;hpb=c84a19db8eeeb89aa3c9cd92ece4bd0306bfbe25;p=org.ibex.core.git

diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java
index 6e80511..3632250 100644
--- a/src/org/xwt/js/JS.java
+++ b/src/org/xwt/js/JS.java
@@ -1,163 +1,201 @@
 // 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 { 
+
+    // Static Interpreter Control Methods ///////////////////////////////////////////////////////////////
+
+    public static int getLine() {
+        Interpreter c = Interpreter.current();
+        return 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 PausedException extends Exception { PausedException() { } }
+
+    public static void invokePauseable(JSFunction function) throws JS.PausedException {
+        Interpreter i = new Interpreter(function, true, new JSArray());
+        int oldpausecount = i.pausecount;
+        i.resume();
+        if (i.pausecount > oldpausecount) throw new PausedException();
+    }
 
+    public static class NotPauseableException extends Exception { NotPauseableException() { } }
 
-    // Public Helper Methods //////////////////////////////////////////////////////////////////////
+    /** 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);
+    }
 
-    /** 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 class UnpauseCallback {
+        Interpreter i;
+        UnpauseCallback(Interpreter i) { this.i = i; }
+        public void unpause(Object o) throws PausedException {
+            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));
+        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 == null) return ZERO;
         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);
+
+        // 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 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 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"); }
-
-
-    // Inner Classes /////////////////////////////////////////////////////////////////////////
-
-    /** A sensible implementation of the abstract methods in the JS class */
-    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; }
-        /** a sealed object cannot have its properties modified */
-        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;
+
+    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 Number N(String s) { return new Double(s); }
+    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; }
+    
+    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); }
+
+
+    // Trap support //////////////////////////////////////////////////////////////////////////////
+
+    /** override and return true to allow placing traps on this object */
+    protected boolean isTrappable() { return false; }
+
+    /** performs a put, triggering traps if present; traps are run in an unpauseable interpreter */
+    public final void putAndTriggerTraps(Object key, Object value) {
+        Trap t = getTrap(key);
+        if (t != null) t.invoke(key, value);
+        else put(key, value);
     }
 
-    /** 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; } 
-    } 
-
-    /** 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); }
+    /** performs a get, triggering traps if present; traps are run in an unpauseable interpreter */
+    public final Object getAndTriggerTraps(Object key) {
+        Trap t = getTrap(key);
+        if (t != null) return t.invoke(key);
+        else return get(key);
     }
 
-    /** 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); }
-    } 
-
-    /** anything that is callable with the () operator */
-    public static abstract class Callable extends JS.Obj {
-        public abstract Object call(JS.Array args) throws JS.Exn;
+    /** retrieve a trap from the entries hash */
+    protected final Trap getTrap(Object key) {
+        return !isTrappable() || entries == null ? null : (Trap)entries.get(key, Trap.class);
     }
 
-    /** a Callable which was compiled from JavaScript code */
-    public static class CompiledFunction extends CompiledFunctionImpl {
-        public Object call(JS.Array args, JS.Scope scope) throws JS.Exn { return super.call(args, scope); }
-        CompiledFunction(String sourceName, int firstLine, Reader sourceCode, Scope scope) throws IOException {
-            super(sourceName, firstLine, sourceCode, scope);
-        }
+    /** retrieve a trap from the entries hash */
+    protected final void putTrap(Object key, Trap value) {
+        if (!isTrappable()) return;
+        if (entries == null) entries = new Hash();
+        entries.put(key, Trap.class, value);
     }
 
-    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 {
+    /** adds a trap, avoiding duplicates */
+    protected final void addTrap(Object name, JSFunction f) {
+        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)));
+    }
 
-        CompiledFunction currentCompiledFunction = null;
-        Vec stack = new Vec();
-        int line = -1;
+    /** 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; }
+    }
 
-        /** binds this thread to the current Java Thread */
-        public void bindToCurrentJavaThread() { javaThreadToJSThread.put(java.lang.Thread.currentThread(), this); }
 
-        /** returns the line of code that is currently executing */
-        public int getLine() { return line; }
+    // Call Support //////////////////////////////////////////////////////////////////////////////
 
-        /** returns the name of the source code file which declared the currently executing function */
-        public String getSourceName() { return currentCompiledFunction == null ? null : currentCompiledFunction.getSourceName();  }
+    // 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) {
+        throw new JSExn("attempted to call the null value (method "+method+")");
+    }    
+    public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) {
+        throw new JSExn("you cannot call this object (class=" + this.getClass().getName() +")");
+    }
 
-        /** fetches the currently-executing javascript function */
-        public JS.CompiledFunction getCurrentCompiledFunction() { return currentCompiledFunction; }
 
+    // Typing Support //////////////////////////////////////////////////////////////////////////////
 
-        // Statics ///////////////////////////////////////////////////////////////////////
+    public Number coerceToNumber() { throw new JSExn("tried to coerce a JavaScript object to a Number"); }
+    public String coerceToString() { throw new JSExn("tried to coerce a JavaScript object to a String"); }
+    public boolean coerceToBoolean() { throw new JSExn("tried to coerce a JavaScript object to a Boolean"); }
 
-        private static Hashtable javaThreadToJSThread = new Hashtable();
+    public String typeName() { return "object"; }
 
-        /** returns the JS thread for a given Java thread, creating one if necessary */
-        public static JS.Thread fromJavaThread(java.lang.Thread t) {
-            JS.Thread ret = (JS.Thread)javaThreadToJSThread.get(t);
-            if (ret == null) {
-                ret = new JS.Thread();
-                ret.bindToCurrentJavaThread();
-            }
-            return ret;
-        }
-        
-    }
 } 
-
-
-
-