checkpoint (refactoring, WIP)

lib/transform.js

@@ -45,22 +45,11 @@
 // XXX: eventually I should refactor the compressor to use this infrastructure.
 
 function TreeTransformer(before, after) {
+    TreeWalker.call(this);
     this.before = before;
     this.after = after;
-    this.stack = [];
 }
-
-TreeTransformer.prototype = {
-    push: function (node) {
-        this.stack.push(node);
-    },
-    pop: function() {
-        return this.stack.pop();
-    },
-    parent: function (n) {
-        return this.stack[this.stack.length - 2 - (n || 0)];
-    }
-};
+TreeTransformer.prototype = new TreeWalker;
 
 (function(undefined){