Added an utility that allows walking depth-first easily.

For example:

w.with_walkers({
    "function": function() {
        var node = w.dive(this); // apply other_walkers to subnodes
        var transformed_node = further_transform(node);
        return transformed_node;
    },
    ... // other_walkers here
}, ...);

(fixes #213)

Author: mishoo

lib/process.js

@@ -223,6 +223,17 @@ function ast_walker() {
                 }
         };
 
+        function dive(ast) {
+                if (ast == null)
+                        return null;
+                try {
+                        stack.push(ast);
+                        return walkers[ast[0]].apply(ast, ast.slice(1));
+                } finally {
+                        stack.pop();
+                }
+        };
+
         function with_walkers(walkers, cont){
                 var save = {}, i;
                 for (i in walkers) if (HOP(walkers, i)) {
@@ -239,6 +250,7 @@ function ast_walker() {
 
         return {
                 walk: walk,
+                dive: dive,
                 with_walkers: with_walkers,
                 parent: function() {
                         return stack[stack.length - 2]; // last one is current node

tmp/test.js

@@ -11,6 +11,20 @@ var ast = jsp.parse(code);
 
 ast = pro.ast_lift_variables(ast);
 
+var w = pro.ast_walker();
+ast = w.with_walkers({
+        "function": function() {
+                var node = w.dive(this); // walk depth first
+                console.log(pro.gen_code(node, { beautify: true }));
+                return node;
+        },
+        "name": function(name) {
+                return [ this[0], "X" ];
+        }
+}, function(){
+        return w.walk(ast);
+});
+
 console.log(pro.gen_code(ast, {
         beautify: true
 }));