X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=6c9448dfa41a9230104d6e177fc378f696538fe8;hb=6076f07a78d5e01a53304b0ae9df97273a0688fe;hp=51929afcd099cfc260285db7d4a27cfc65aba487;hpb=9b9482f2939c8cb7526a8ca7ff43a7f2c2b5f97a;p=org.ibex.core.git

diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java
index 51929af..6c9448d 100644
--- a/src/org/xwt/js/JS.java
+++ b/src/org/xwt/js/JS.java
@@ -1,55 +1,239 @@
-// 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 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 { 
+
+
+    // Static Methods //////////////////////////////////////////////////////////////////////
+
+    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 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;
+    }
+
+    public static long toLong(Object o) { return toNumber(o).longValue(); }
+    public static double toDouble(Object o) { return toNumber(o).doubleValue(); }
+    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");
+    }
+
+
+    // Instance Methods ////////////////////////////////////////////////////////////////////
  
-/** The public API for the JS engine */
-public interface JS { 
- 
-    public Object get(Object key) throws JS.Exn; 
-    public Object put(Object key, Object val) throws JS.Exn; 
-    public Object[] enumerateProperties(); 
-    public String coerceToString() throws JS.Exn; 
-    /*
-    public Num coerceToNumber() throws JS.Exn; 
-    public boolean coerceToBoolean() throws JS.Exn; 
-    public Object call(Object[] args) throws JS.Exn; 
-    */
-    /** if JS calls a Java method, and the Java method throws an exception, it can only be caught by JS if it is a subclass of Exn. */ 
+    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 interface Scope extends JS { 
-	public boolean has(Object key); 
-	public void declare(String s);
-	public JS getParentScope(); 
+    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);
+	}
     } 
  
-    /** A mutable, boxed numeric value.  These are recycled -- never duplicate references -- use duplicate() instead. */ 
-	/*
-    public static class Num implements Cloneable, JS { 
-	 
-	private Num() { } 
-	public boolean isDouble = false; 
-	public long longVal = -1; 
-	public double doubleVal = -1; 
-	 
-	private static Vec pool = new Vec(); 
-	public static synchronized void recycle(Num n) { pool.push(n); } 
-	public static synchronized Num getOne() { return (pool.size() > 0) ? (Num)pool.pop() : new Num(); } 
-	 
-	public Num duplicate() { try { return (Num)clone(); } catch (CloneNotSupportedException c) { throw new Error(c); } } 
- 
-	public Object get(Object key) throws JS.Exn { return null; } 
-	public Object put(Object key, Object val) throws JS.Exn { throw new JS.Exn("attempt to set a property on a Number"); } 
-	public Object[] enumerateProperties() { return new Object[] { }; } 
-	public String coerceToString() throws JS.Exn { return isDouble ? String.valueOf(doubleVal) : String.valueOf(longVal); } 
-	public Num coerceToNumber() throws JS.Exn { return duplicate(); } 
-	public Object call(Object[] args) throws JS.Exn { throw new JS.Exn("attempt to apply the () operator to a Number"); } 
-    } 
-	*/
+    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);
+	}
+    }
 } 
+
+
+
+