From e8786f49ffc5f95ebe2229763bf5505e809e7cf2 Mon Sep 17 00:00:00 2001
From: yann300 <yann.levreau@gmail.com>
Date: Wed, 10 Aug 2016 15:10:01 +0200
Subject: [PATCH] astcrawler

---
 src/index.js          |  4 +++-
 src/util/astWalker.js | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 1 deletion(-)
 create mode 100644 src/util/astWalker.js

diff --git a/src/index.js b/src/index.js
index 2325fe9d97..77da64ba23 100644
--- a/src/index.js
+++ b/src/index.js
@@ -5,6 +5,7 @@ var BasicPanel = require('./ui/BasicPanel')
 var TraceManager = require('./trace/traceManager')
 var CodeManager = require('./code/codeManager')
 var SourceMappingDecoder = require('./util/sourceMappingDecoder')
+var AstWalker = require('./util/astWalker')
 
 if (typeof (module) !== 'undefined' && typeof (module.exports) !== 'undefined') {
   module.exports = modules()
@@ -24,7 +25,8 @@ function modules () {
       BasicPanel: BasicPanel
     },
     util: {
-      SourceMappingDecoder: SourceMappingDecoder
+      SourceMappingDecoder: SourceMappingDecoder,
+      AstWalker: AstWalker
     }
   }
 }
diff --git a/src/util/astWalker.js b/src/util/astWalker.js
new file mode 100644
index 0000000000..7e38011d94
--- /dev/null
+++ b/src/util/astWalker.js
@@ -0,0 +1,40 @@
+'use strict'
+/*
+  Crawl the given AST through the function walk(ast, callback)
+*/
+function AstWalker () {
+}
+/*
+    * visit all the AST nodes
+    *
+    * @param {Object} ast  - AST node
+    * @param {Object or Function} callback  - if (Function) the function will be called for every node.
+    *                                       - if (Object) callback[<Node Type>] will be called for every node of type <Node Type>. callback["*"] will be called fo all other nodes.
+    *                                     in each case, if the callback returns false it does not descend into children. If no callback for the current type, children are visited.
+*/
+AstWalker.prototype.walk = function (ast, callback) {
+  crawlNode(ast, callback)
+}
+
+function crawlNode (node, callback) {
+  if (manageCallBack(node, callback) && node.children && node.children.length > 0) {
+    for (var k in node.children) {
+      var child = node.children[k]
+      crawlNode(child, callback)
+    }
+  }
+}
+
+function manageCallBack (node, callback) {
+  if (callback instanceof Function) {
+    return callback(null, node)
+  } else if (callback instanceof Object) {
+    if (callback[node.name] instanceof 'Function') {
+      return callback[node.name](null, node)
+    } else if (callback['*'] instanceof 'Function') {
+      return callback['*'](null, node)
+    } else {
+      return true
+    }
+  }
+}