--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dmdscript_tango/iterator.d	Sun Jan 24 12:34:47 2010 +0200
@@ -0,0 +1,121 @@
+
+/* Digital Mars DMDScript source code.
+ * Copyright (c) 2000-2002 by Chromium Communications
+ * D version Copyright (c) 2004-2005 by Digital Mars
+ * All Rights Reserved
+ * written by Walter Bright
+ * www.digitalmars.com
+ * Use at your own risk. There is no warranty, express or implied.
+ * License for redistribution is by the GNU General Public License in gpl.txt.
+ *
+ * A binary, non-exclusive license for commercial use can be
+ * purchased from www.digitalmars.com/dscript/buy.html.
+ *
+ * DMDScript is implemented in the D Programming Language,
+ * www.digitalmars.com/d/
+ *
+ * For a C++ implementation of DMDScript, including COM support,
+ * see www.digitalmars.com/dscript/cppscript.html.
+ */
+
+
+module dmdscript.iterator;
+
+import dmdscript.script;
+import dmdscript.dobject;
+import dmdscript.value;
+import dmdscript.property;
+
+Dobject getPrototype(Dobject o)
+{
+    version (all)
+    {
+	return o.internal_prototype;	// use internal [[Prototype]]
+    }
+    else
+    {
+	// use "prototype"
+	Value *v;
+
+	v = o.Get(TEXT_prototype);
+	if (!v || v.isPrimitive())
+	    return null;
+	o = v.toObject();
+	return o;
+    }
+}
+
+struct Iterator
+{
+    Value[] keys;
+    size_t keyindex;
+    Dobject o;
+    Dobject ostart;
+
+    debug
+    {
+	const uint ITERATOR_VALUE = 0x1992836;
+	uint foo = ITERATOR_VALUE;
+    }
+
+    invariant
+    {
+	debug assert(foo == ITERATOR_VALUE);
+    }
+
+    void ctor(Dobject o)
+    {
+	debug foo = ITERATOR_VALUE;
+	//writef("Iterator: o = %p, p = %p\n", o, p);
+	ostart = o;
+	this.o = o;
+	keys = o.proptable.table.keys.sort;
+	keyindex = 0;
+    }
+
+    Value *next()
+    {	Property* p;
+
+	//writef("Iterator::done() p = %p\n", p);
+
+	for (; ; keyindex++)
+	{
+	    while (keyindex == keys.length)
+	    {
+		delete keys;
+		o = getPrototype(o);
+		if (!o)
+		    return null;
+		keys = o.proptable.table.keys.sort;
+		keyindex = 0;
+	    }
+	    Value* key = &keys[keyindex];
+	    p = *key in o.proptable.table;
+	    if (!p)			// if no longer in property table
+		continue;
+	    if (p.attributes & DontEnum)
+		continue;
+	    else
+	    {
+		// ECMA 12.6.3
+		// Do not enumerate those properties in prototypes
+		// that are overridden
+		if (o != ostart)
+		{
+		    for (Dobject ot = ostart; ot != o; ot = getPrototype(ot))
+		    {
+			// If property p is in t, don't enumerate
+			if (*key in ot.proptable.table)
+			    goto Lcontinue;
+		    }
+		}
+		keyindex++;
+		return key; //&p.value;
+
+	    Lcontinue:
+		;
+	    }
+	}
+	assert(0);
+    }
+}