From 60dae7a88d80cb0daf5b998a4e69994a6db91ed1 Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Thu, 15 Jan 2015 20:13:24 +1100
Subject: [PATCH] add build comprehension helper

---
 .../helpers/build-comprehension.js            | 23 ++++++++++++++
 .../transformers/es7-array-comprehension.js   | 31 +++----------------
 .../es7-generator-comprehension.js            |  4 +--
 3 files changed, 30 insertions(+), 28 deletions(-)
 create mode 100644 lib/6to5/transformation/helpers/build-comprehension.js

diff --git a/lib/6to5/transformation/helpers/build-comprehension.js b/lib/6to5/transformation/helpers/build-comprehension.js
new file mode 100644
index 0000000000..9ba979caef
--- /dev/null
+++ b/lib/6to5/transformation/helpers/build-comprehension.js
@@ -0,0 +1,23 @@
+var t = require("../../types");
+
+module.exports = function build(node, buildBody) {
+  var self = node.blocks.shift();
+  if (!self) return;
+
+  var child = build(node, buildBody);
+  if (!child) {
+    // last item
+    child = buildBody();
+
+    // add a filter as this is our final stop
+    if (node.filter) {
+      child = t.ifStatement(node.filter, t.blockStatement([child]));
+    }
+  }
+
+  return t.forOfStatement(
+    t.variableDeclaration("let", [t.variableDeclarator(self.left)]),
+    self.right,
+    t.blockStatement([child])
+  );
+};
diff --git a/lib/6to5/transformation/transformers/es7-array-comprehension.js b/lib/6to5/transformation/transformers/es7-array-comprehension.js
index a988678d93..0a18a94e8a 100644
--- a/lib/6to5/transformation/transformers/es7-array-comprehension.js
+++ b/lib/6to5/transformation/transformers/es7-array-comprehension.js
@@ -1,6 +1,7 @@
-var traverse = require("../../traverse");
-var util     = require("../../util");
-var t        = require("../../types");
+var buildComprehension = require("../helpers/build-comprehension");
+var traverse           = require("../../traverse");
+var util               = require("../../util");
+var t                  = require("../../types");
 
 exports.experimental = true;
 
@@ -22,7 +23,7 @@ var build = function (node, parent, file, scope) {
 
   var returnStatement = body.pop();
 
-  body.push(exports._build(node, function () {
+  body.push(buildComprehension(node, function () {
     return util.template("array-push", {
       STATEMENT: node.body,
       KEY:       uid
@@ -33,28 +34,6 @@ var build = function (node, parent, file, scope) {
   return container;
 };
 
-exports._build = function (node, buildBody) {
-  var self = node.blocks.shift();
-  if (!self) return;
-
-  var child = exports._build(node, buildBody);
-  if (!child) {
-    // last item
-    child = buildBody();
-
-    // add a filter as this is our final stop
-    if (node.filter) {
-      child = t.ifStatement(node.filter, t.blockStatement([child]));
-    }
-  }
-
-  return t.forOfStatement(
-    t.variableDeclaration("let", [t.variableDeclarator(self.left)]),
-    self.right,
-    t.blockStatement([child])
-  );
-};
-
 exports.ComprehensionExpression = function (node, parent, file, scope) {
   if (node.generator) return;
 
diff --git a/lib/6to5/transformation/transformers/es7-generator-comprehension.js b/lib/6to5/transformation/transformers/es7-generator-comprehension.js
index 9d950fecd3..84d75634a1 100644
--- a/lib/6to5/transformation/transformers/es7-generator-comprehension.js
+++ b/lib/6to5/transformation/transformers/es7-generator-comprehension.js
@@ -1,4 +1,4 @@
-var arrayComprehension = require("./es7-array-comprehension");
+var buildComprehension = require("../helpers/build-comprehension");
 var t                  = require("../../types");
 
 exports.experimental = true;
@@ -10,7 +10,7 @@ exports.ComprehensionExpression = function (node) {
   var container = t.functionExpression(null, [], t.blockStatement(body), true);
   container._aliasFunction = true;
 
-  body.push(arrayComprehension._build(node, function () {
+  body.push(buildComprehension(node, function () {
     return t.expressionStatement(t.yieldExpression(node.body));
   }));