Use ES2015 let, const, for of

.travis.yml

@@ -1,6 +1,5 @@
 node_js:
-- "0.12"
-- "iojs"
+- "4.0"
 language: node_js
 script: "npm run-script test-travis"
 after_script: "npm install coveralls@2 && cat ./coverage/lcov.info | coveralls"

History.md

@@ -1,3 +1,9 @@
+4.7.0 / 2015-07-09
+==================
+
+ * Drop support for node < 4.0, use ES2016 syntax
+
+
 4.6.0 / 2015-07-09
 ==================
 

Readme.md

@@ -19,7 +19,7 @@
 
 ```js
 co(function* () {
-  var result = yield Promise.resolve(true);
+  let result = yield Promise.resolve(true);
   return result;
 }).then(function (value) {
   console.log(value);
@@ -32,7 +32,7 @@ co(function* () {
   you now use `co.wrap(fn*)`.
 
 ```js
-var fn = co.wrap(function* (val) {
+let fn = co.wrap(function* (val) {
   return yield Promise.resolve(val);
 });
 
@@ -43,17 +43,7 @@ fn(true).then(function (val) {
 
 ## Platform Compatibility
 
-  `co@4+` requires a `Promise` implementation.
-  For versions of node `< 0.11` and for many older browsers,
-  you should/must include your own `Promise` polyfill.
-
-  When using node 0.11.x or greater, you must use the `--harmony-generators`
-  flag or just `--harmony` to get access to generators.
-
-  When using node 0.10.x and lower or browsers without generator support,
-  you must use [gnode](https://github.com/TooTallNate/gnode) and/or [regenerator](http://facebook.github.io/regenerator/).
-
-  io.js is supported out of the box, you can use `co` without flags or polyfills.
+  `co` require a node version higher than 4.0 for Generator, Promise and other ES2015 feature support.
 
 ## Installation
 
@@ -72,19 +62,19 @@ View the [wiki](https://github.com/visionmedia/co/wiki) for more libraries.
 ## Examples
 
 ```js
-var co = require('co');
+let co = require('co');
 
 co(function *(){
   // yield any promise
-  var result = yield Promise.resolve(true);
+  let result = yield Promise.resolve(true);
 }).catch(onerror);
 
 co(function *(){
   // resolve multiple promises in parallel
-  var a = Promise.resolve(1);
-  var b = Promise.resolve(2);
-  var c = Promise.resolve(3);
-  var res = yield [a, b, c];
+  let a = Promise.resolve(1);
+  let b = Promise.resolve(2);
+  let c = Promise.resolve(3);
+  let res = yield [a, b, c];
   console.log(res);
   // => [1, 2, 3]
 }).catch(onerror);
@@ -136,7 +126,7 @@ be removed in future versions of `co`.
 
 ```js
 co(function* () {
-  var res = yield [
+  let res = yield [
     Promise.resolve(1),
     Promise.resolve(2),
     Promise.resolve(3),
@@ -151,7 +141,7 @@ Just like arrays, objects resolve all `yieldable`s in parallel.
 
 ```js
 co(function* () {
-  var res = yield {
+  let res = yield {
     1: Promise.resolve(1),
     2: Promise.resolve(2),
   };
@@ -182,12 +172,12 @@ co(function* () {
 });
 ```
 
-### var fn = co.wrap(fn*)
+### let fn = co.wrap(fn*)
 
 Convert a generator into a regular function that returns a `Promise`.
 
 ```js
-var fn = co.wrap(function* (val) {
+let fn = co.wrap(function* (val) {
   return yield Promise.resolve(val);
 });
 

component.json

@@ -1,6 +1,6 @@
 {
   "name": "co",
-  "version": "4.4.0",
+  "version": "4.7.0",
   "description": "generator async control flow goodness",
   "keywords": [
     "async",

index.js

@@ -1,9 +1,9 @@
-
+'use strict';
 /**
  * slice() reference.
  */
 
-var slice = Array.prototype.slice;
+const slice = Array.prototype.slice;
 
 /**
  * Expose `co`.
@@ -41,8 +41,8 @@ co.wrap = function (fn) {
  */
 
 function co(gen) {
-  var ctx = this;
-  var args = slice.call(arguments, 1)
+  const ctx = this;
+  const args = slice.call(arguments, 1);
 
   // we wrap everything in a promise to avoid promise chaining,
   // which leads to memory leak errors.
@@ -60,7 +60,7 @@ function co(gen) {
      */
 
     function onFulfilled(res) {
-      var ret;
+      let ret;
       try {
         ret = gen.next(res);
       } catch (e) {
@@ -76,7 +76,7 @@ function co(gen) {
      */
 
     function onRejected(err) {
-      var ret;
+      let ret;
       try {
         ret = gen.throw(err);
       } catch (e) {
@@ -96,10 +96,9 @@ function co(gen) {
 
     function next(ret) {
       if (ret.done) return resolve(ret.value);
-      var value = toPromise.call(ctx, ret.value);
+      let value = toPromise.call(ctx, ret.value);
       if (value && isPromise(value)) return value.then(onFulfilled, onRejected);
-      return onRejected(new TypeError('You may only yield a function, promise, generator, array, or object, '
-        + 'but the following object was passed: "' + String(ret.value) + '"'));
+      return onRejected(new TypeError(`You may only yield a function, promise, generator, array, or object, but the following object was passed: "${String(ret.value)}"`));
     }
   });
 }
@@ -131,7 +130,7 @@ function toPromise(obj) {
  */
 
 function thunkToPromise(fn) {
-  var ctx = this;
+  const ctx = this;
   return new Promise(function (resolve, reject) {
     fn.call(ctx, function (err, res) {
       if (err) return reject(err);
@@ -164,12 +163,11 @@ function arrayToPromise(obj) {
  */
 
 function objectToPromise(obj){
-  var results = new obj.constructor();
-  var keys = Object.keys(obj);
-  var promises = [];
-  for (var i = 0; i < keys.length; i++) {
-    var key = keys[i];
-    var promise = toPromise.call(this, obj[key]);
+  let results = new obj.constructor();
+  let keys = Object.keys(obj);
+  let promises = [];
+  for (let key of keys) {
+    let promise = toPromise.call(this, obj[key]);
     if (promise && isPromise(promise)) defer(promise, key);
     else results[key] = obj[key];
   }
@@ -218,7 +216,7 @@ function isGenerator(obj) {
  * @api private
  */
 function isGeneratorFunction(obj) {
-  var constructor = obj.constructor;
+  const constructor = obj.constructor;
   if (!constructor) return false;
   if ('GeneratorFunction' === constructor.name || 'GeneratorFunction' === constructor.displayName) return true;
   return isGenerator(constructor.prototype);

package.json

@@ -1,6 +1,6 @@
 {
   "name": "co",
-  "version": "4.6.0",
+  "version": "4.7.0",
   "description": "generator async control flow goodness",
   "keywords": [
     "async",
@@ -10,17 +10,18 @@
     "coroutine"
   ],
   "devDependencies": {
+    "babelify": "^6.4.0",
     "browserify": "^10.0.0",
-    "istanbul-harmony": "0",
+    "istanbul": "^0.4.0",
     "mocha": "^2.0.0",
-    "mz": "^1.0.2"
+    "mz": "^2.1.0"
   },
   "scripts": {
-    "test": "mocha --harmony",
-    "test-cov": "node --harmony node_modules/.bin/istanbul cover ./node_modules/.bin/_mocha -- --reporter dot",
-    "test-travis": "node --harmony node_modules/.bin/istanbul cover ./node_modules/.bin/_mocha --report lcovonly -- --reporter dot",
+    "test": "mocha",
+    "test-cov": "node node_modules/.bin/istanbul cover ./node_modules/.bin/_mocha -- --reporter dot",
+    "test-travis": "node node_modules/.bin/istanbul cover ./node_modules/.bin/_mocha --report lcovonly -- --reporter dot",
     "prepublish": "npm run browserify",
-    "browserify": "browserify index.js -o ./co-browser.js -s co"
+    "browserify": "browserify index.js -t babelify -o ./co-browser.js -s co"
   },
   "files": [
     "co-browser.js",
@@ -29,7 +30,6 @@
   "license": "MIT",
   "repository": "tj/co",
   "engines": {
-    "iojs": ">= 1.0.0",
-    "node": ">= 0.12.0"
+    "node": ">= 4.0"
   }
 }