Merge pull request #3 from omsmith/optimize

optimize to reduce allocations (also for speed)

lib/promise-settle.js

@@ -3,53 +3,53 @@
 module.exports = settle;
 
 function settle(promises) {
-  return Promise.resolve()
-    .then(function () {
-      return promises;
-    })
-    .then(function (promises) {
-      if (!Array.isArray(promises)) throw new TypeError('Expected an array of Promises');
-
-      var promiseResults = promises.map(function (promise) {
-        return Promise.resolve()
-          .then(function () {
-            return promise;
-          })
-          .then(function (result) {
-            return promiseResult(result);
-          })
-          .catch(function (err) {
-            return promiseResult(null, err);
-          });
-      });
-
-      return Promise.all(promiseResults);
-    });
-}
-
-function promiseResult(result, err) {
-  var isFulfilled = (typeof err === 'undefined');
-  var value = isFulfilled
-    ? returns.bind(result)
-    : throws.bind(new Error('Promise is rejected'));
-
-  var isRejected = !isFulfilled;
-  var reason = isRejected
-    ? returns.bind(err)
-    : throws.bind(new Error('Promise is fulfilled'));
+  return Promise
+    .resolve(promises)
+    .then(_settle);
+}
+
+function _settle(promises) {
+  if (!Array.isArray(promises)) throw new TypeError('Expected an array of Promises');
+
+  return Promise.all(promises.map(_settlePromise));
+}
+
+function _settlePromise(promise) {
+  return Promise
+    .resolve(promise)
+    .then(_promiseResolved, _promiseRejected);
+}
+
+function _promiseResolved(result) {
+  return {
+    isFulfilled: _true,
+    isRejected: _false,
+    value: function () { return result; },
+    reason: _isFulfilled
+  };
+}
 
+function _promiseRejected(err) {
   return {
-    isFulfilled: returns.bind(isFulfilled),
-    isRejected: returns.bind(isRejected),
-    value: value,
-    reason: reason
+    isFulfilled: _false,
+    isRejected: _true,
+    value: _isRejected,
+    reason: function () { return err; }
   };
 }
 
-function returns() {
-  return this;
+function _true() {
+  return true;
+}
+
+function _false() {
+  return false;
+}
+
+function _isRejected() {
+  throw new Error('Promise is rejected');
 }
 
-function throws() {
-  throw this;
+function _isFulfilled() {
+  throw new Error('Promise is fulfilled');
 }