diff --git a/lib/javascript/gflib.js b/lib/javascript/gflib.js
index 2097e53ae..5c05259f0 100644
--- a/lib/javascript/gflib.js
+++ b/lib/javascript/gflib.js
@@ -1,10 +1,7 @@
 /* Abstract syntax trees */
-
 function Fun(name) {
 	this.name = name;
-	for (var i = 1; i < arguments.length; i++) {
-	    this.setChild(i-1, arguments[i]);
-	}
+	this.children = copy_arguments(arguments, 1);
 }
 Fun.prototype.print = function () { return this.show(0); } ;
 Fun.prototype.show = function (prec) {
@@ -31,21 +28,13 @@ Fun.prototype.show = function (prec) {
 	}
 };
 Fun.prototype.getChild = function (i) {
-	return this['arg'+i];
+	return this.children[i];
 };
 Fun.prototype.setChild = function (i,c) {
-	this['arg'+i] = c;
+	this.children[i] = c;
 };
-/* Gets an array containing all the children. Modifying the array does not
-   change the tree, but modifying the elements of the array does. */
 Fun.prototype.getChildren = function () {
-	var a = new Array();
-	for (var i = 0; ; i++) {
-		var c = this.getChild(i);
-		if (isUndefined(c)) { break; }
-		a.push(c);
-	}
-	return a;
+  return this.children;
 } ;
 Fun.prototype.isMeta = function() {
 	return this.name == '?';
@@ -110,22 +99,23 @@ Abstract.prototype.annotate = function(tree, type) {
 	} else {
 		var typ = this.types[tree.name];
 		var cs = tree.getChildren();
-		for (var i = 0; i < cs.length; i++) {
+		for (var i in cs) {
 			this.annotate(cs[i], typ.args[i]);
 		}
 	}
 	return tree;
 } ;
 /* Hack to get around the fact that our SISR doesn't build real Fun objects. */
-Abstract.prototype.copyTree = function(x, type) {
-	return this.annotate(this.copyTree_(x), type);
-};
-Abstract.prototype.copyTree_ = function(x) {
+Abstract.prototype.copyTree = function(x) {
 	var t = new Fun(x.name);
-	for (var i = 0; ; i++) {
-		var c = x['arg' + i];
-		if (isUndefined(c)) { break; }
-		t.setChild(i, this.copyTree(c));
+	if (!isUndefined(x.type)) {
+	  t.type = x.type;
+	}
+	var cs = x.children;
+	if (!isUndefined(cs)) {
+	  for (var i in cs) {
+	    t.setChild(i, this.copyTree(cs[i]));
+	  }
 	}
 	return t;
 } ;
@@ -177,7 +167,7 @@ Concrete.prototype.linearizeToTerm = function (tree) {
 		}
 	} else {
 		var cs = tree.getChildren();
-		for (var i = 0; i < cs.length; i++) {
+		for (var i in cs) {
 			cs[i] = this.linearizeToTerm(cs[i]);
 		}
 		return this.rule(tree.name, cs);
@@ -203,7 +193,7 @@ function dumpObject (obj) {
 		return obj.toString();
 	} else if (isArray(obj)) {
 		var x = "[";
-		for (var i = 0; i < obj.length; i++) {
+		for (var i in obj) {
 			x += dumpObject(obj[i]);
 			if (i < obj.length-1) {
 				x += ",";
@@ -230,7 +220,7 @@ function copy_arguments(args, start) {
 
 function join_print(values, glue) {
 	var str = "";
-	for (var i = 0; i < values.length; i++) {
+	for (var i in values) {
 		var s = values[i].print();
 		if (s.length > 0) {
 			if (str.length > 0) { str += glue; }
diff --git a/src/GF/Speech/SISR.hs b/src/GF/Speech/SISR.hs
index b74b44076..9e926c72f 100644
--- a/src/GF/Speech/SISR.hs
+++ b/src/GF/Speech/SISR.hs
@@ -82,7 +82,7 @@ field x y = JS.EMember x (JS.Ident y)
 
 ass = JS.EAssign
 
-tree n xs = obj $ [("name", JS.EStr n)] ++ [("arg"++show i, x) | (i,x) <- zip [0..] xs]
+tree n xs = obj [("name", JS.EStr n), ("children", JS.EArray xs)]
 
 obj ps = JS.EObj [JS.Prop (JS.Ident x) y | (x,y) <- ps]