X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=c6d5dd6b0a97ad0ca1f985882083b16facdb5933;hb=6261c41b2ac9d182d8c3541e8e0e5fd00062fa43;hp=635d4e55453fbefbf308492d4c0be10f10733ba0;hpb=55ba92deb32e860a485d544479850e98288cee43;p=org.ibex.core.git

diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java
index 635d4e5..c6d5dd6 100644
--- a/src/org/xwt/js/JS.java
+++ b/src/org/xwt/js/JS.java
@@ -1,28 +1,55 @@
 // 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 { 
-
-    // Public Helper Methods //////////////////////////////////////////////////////////////////////
-
-    /** parse and compile a function */
-    public static Function parse(String sourceName, int firstLine, Reader sourceCode) throws IOException {
-        return new Function(sourceName, firstLine, sourceCode, null);
+/** 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 ///////////////////////////////////////////////////////////////
+
+    /** 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 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;
@@ -49,18 +76,18 @@ public abstract class JS {
 
     /** 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);
 
         // 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);
+            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";
@@ -74,198 +101,124 @@ public abstract class JS {
         }
         return o.toString();
     }
+
     
     // Instance Methods ////////////////////////////////////////////////////////////////////
+
+    public static final Integer ZERO = new Integer(0);
  
-    public abstract Object get(Object key) throws JS.Exn; 
-    public abstract Object put(Object key, Object val) throws JS.Exn; 
-    public abstract Object[] keys(); 
-    public Object callMethod(Object method, Array args, boolean checkOnly) throws JS.Exn {
-	if (checkOnly) return Boolean.FALSE;
-	Object o = get(method);
-	if (o instanceof JS.Callable) return ((JS.Callable)o).call(args);
-        else if (o == null) throw new JS.Exn("Attempted to call non-existent method: " + method);
-        else throw new JS.Exn("Attempted to call a non-function: " +method);
+    // 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;
     }
     
-    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 /////////////////////////////////////////////////////////////////////////
-
-    /** A sensible implementation of the abstract methods in the JS class */
-    public static class Obj extends JS {
-        private Hash entries = null;
-        private boolean sealed = false;
-        public Obj() { this(false); }
-        public Obj(boolean sealed) { this.sealed = sealed; }
-        public void setSeal(boolean sealed) { this.sealed = sealed; }      ///< a sealed object cannot have its properties modified
-        public Object put(Object key, Object val) { put2(key, null, val); return null; }
-        protected void put2(Object key, Object key2, Object val) {
-            if (sealed) return;
-            if (entries == null) entries = new Hash();
-            entries.put(key, key2, val); }
-        public Object[] keys() { return entries == null ? new Object[0] : entries.keys(); }
-        public Object get(Object key) { return get(key, null); }
-        protected Object get(Object key, Object key2) {
-            if (entries == null) return null;
-            if(key2 == null && callMethod((String)key, null, true) == Boolean.TRUE)
-                return new Internal.CallableStub(this, key);
-            return entries.get(key, key2);
-        }
+    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);
     }
 
-    /** 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); }
-        public Object get(Object key) { return super._get(key); }
-        public Object put(Object key, Object val) { super._put(key, val); return null; }
-    }
+    // Trap support //////////////////////////////////////////////////////////////////////////////
 
-    /** 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); }
-        public boolean has(Object key) { return super.has(key); }
-        public Object get(Object key) { return super._get(key); }
-        public Object put(Object key, Object val) { super._put(key, val); return null; }
-        public void declare(String s) { super.declare(s); }
-    } 
+    /** 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 false; }
 
-    /** the result of a graft */
-    public static class Graft extends JS {
-        private JS graftee;
-        private Object replaced_key;
-        private Object replaced_val;
-        public Graft(JS graftee, Object key, Object val) {
-            if (graftee instanceof Array) throw new JS.Exn("can't graft onto Arrays (yet)");
-            if (graftee instanceof Callable) throw new JS.Exn("can't graft onto Callables (yet)");
-            if (graftee instanceof Scope) throw new JS.Exn("can't graft onto Scopes (yet)");
-            this.graftee = 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 Object put(Object key, Object val) { graftee.put(key, val); return null; }
-        public Object callMethod(Object method, Array args, boolean checkOnly) throws JS.Exn {
-            if (!replaced_key.equals(method)) return graftee.callMethod(method, args, checkOnly);
-            if (replaced_val instanceof Callable) return checkOnly ? Boolean.TRUE : ((Callable)replaced_val).call(args);
-            if (checkOnly) return Boolean.FALSE;
-            throw new JS.Exn("attempt to call non-function");
-        }
-        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 Object[] keys() {
-            Object[] ret = graftee.keys();
-            for(int i=0; i<ret.length; i++) if (replaced_key.equals(ret[i])) return ret;
-            Object[] ret2 = new Object[ret.length + 1];
-            System.arraycopy(ret, 0, ret2, 0, ret.length);
-            ret2[ret2.length - 1] = replaced_key;
-            return ret2;
-        }
+    /** 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);
     }
 
-    /** anything that is callable with the () operator and wasn't compiled from JS code */
-    public static abstract class Callable extends JS.Obj {
-        public abstract Object call(JS.Array args) throws JS.Exn;
+    /** 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);
     }
 
-    /** a scope that is populated with js objects and functions normally found in the global scope */
-    public static class GlobalScope extends GlobalScopeImpl {
-        public GlobalScope() { this(null); }
-        public GlobalScope(JS.Scope parent) { super(parent); }
+    /** retrieve a trap from the entries hash */
+    protected final Trap getTrap(Object key) {
+        return entries == null ? null : (Trap)entries.get(key, Trap.class);
     }
 
-    public static class TailCall {
-        Function func = null;
-        JS.Array args = null;
-        public TailCall() { }
-        public TailCall set(Function func) { this.func = func; this.args = new JS.Array(); return this; }
-        public TailCall set(Function func, JS.Array args) { this.func = func; this.args = args; return this; }
+    /** 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);
     }
- 
-    /** encapsulates the state of a JavaScript "thread" (ie stack) */
-    public static class Context {
-
-
-        // Statics //////////////////////////////////////////////////////////////////////
-
-        /**
-         *  Return this from call/get/put in order to make the interpreter pause.  The interpreter will expect a value
-         *  (the return from the call or the get) to be pushed onto the stack when it is resumed.
-         */
-        public static Object pause = new Object();
 
-        private int getLine_() { return current().f == null ? -1 : (pc < 0 || pc >= f.size) ? -1 : f.line[pc]; }
-        public static int getLine() { return current().getLine_(); }
-        public static String getSourceName() { return current().f == null ? null : current().f.sourceName; } 
-
-        /** fetches the currently-executing javascript function */
-        public static JS.Context current() { return (JS.Context)threadToContext.get(Thread.currentThread()); }
-        private static Hashtable threadToContext = new Hashtable();
+    /** 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; }
+    }
 
-        // Instance members and methods //////////////////////////////////////////////////////////////////////
 
-        /** the currently-executing Function */
-        Function f = null;
+    // Call Support //////////////////////////////////////////////////////////////////////////////
 
-        /** the currently-executing scope */
-        public Scope scope = null;  // FIXME: do we really need this?  the function should contain this info
+    // 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() +")");
+    }
 
-        /** the object stack */
-        Vec stack = new Vec();
 
-        /** the program counter */
-        int pc = 0;
+    // Typing Support //////////////////////////////////////////////////////////////////////////////
 
-        public Context(Function function, Scope scope) {
-            if (scope == null) scope = new Scope(function.parentScope);
-            stack.push(new Function.CallMarker(this));
-            stack.push(new JS.Array());
-            this.f = function;
-            this.scope = scope;
-        }
+    public Number coerceToNumber() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a Number"); }
+    public String coerceToString() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a String"); }
+    public boolean coerceToBoolean() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a Boolean"); }
 
-        public Object resume() { return resume(null); }
-        public Object resume(Object o) {
-            Thread t = Thread.currentThread();
-            Context old = (Context)threadToContext.get(t);
-            try {
-                threadToContext.put(t, this);
-                stack.push(o);
-                return Function.eval(this);
-            } finally {
-                if (old == null) threadToContext.remove(t);
-                else threadToContext.put(t, old);
-            }
-        }
+    public String typeName() { return "object"; }
 
-    }
 } 
-
-
-
-