move transformers over to using ast-types when constructing new nodes

lib/6to5/transformers/destructuring.js

@@ -1,4 +1,5 @@
 var util = require("../util");
+var b    = require("ast-types").builders;
 var _    = require("lodash");
 
 var isPattern = function (id) {
@@ -20,15 +21,9 @@ exports.VariableDeclaration = function (node, parent, opts, generateUid) {
   //
 
   var buildVariableAssign = function (id, init) {
-    return {
-      type: "VariableDeclaration",
-      kind: node.kind,
-      declarations: [{
-        type: "VariableDeclarator",
-        id: id,
-        init: init
-      }]
-    };
+    return b.variableDeclaration(node.kind, [
+      b.variableDeclarator(id, init)
+    ]);
   };
 
   var push = function (pattern, parentId) {
@@ -43,11 +38,7 @@ exports.VariableDeclaration = function (node, parent, opts, generateUid) {
     _.each(pattern.properties, function (prop) {
       var id = prop.value;
 
-      var init = {
-        type: "MemberExpression",
-        object: parentId,
-        property: prop.key
-      };
+      var init = b.memberExpression(parentId, prop.key, false);
 
       if (isPattern(id)) {
         push(id, init);
@@ -59,15 +50,7 @@ exports.VariableDeclaration = function (node, parent, opts, generateUid) {
 
   var pushArrayPattern = function (pattern, parentId) {
     _.each(pattern.elements, function (id, i) {
-      var init = {
-        type: "MemberExpression",
-        computed: true,
-        object: parentId,
-        property: {
-          type: "Literal",
-          value: i
-        }
-      };
+      var init = b.memberExpression(parentId, b.literal(i), true);
 
       if (id.type === "Identifier") {
         nodes.push(buildVariableAssign(id, init));
@@ -86,10 +69,7 @@ exports.VariableDeclaration = function (node, parent, opts, generateUid) {
         VALUE: init
       }, true));
 
-      init = {
-        type: "Identifier",
-        name: key
-      };
+      init = b.identifier(key);
     }
 
     push(id, init);