setImediate + error handling

setImediate = +30% to speed
Error handling by default = + 500% to useability

Author: ForbesLindesay

index.js

@@ -1,89 +1,98 @@
-var isPromise = require('is-promise')
-
-var extensions = [];
-
-module.exports = Promise
-function Promise(fn) {
-  if (!(this instanceof Promise)) {
-    return typeof fn === 'function' ? new Promise(fn) : defer()
-  }
-  var isResolved = false
-  var isFulfilled = false
-  var value
-  var waiting = []
-  var running = false
-
-  function next(skipTimeout) {
-    if (waiting.length) {
-      running = true
-      waiting.shift()(skipTimeout || false)
-    } else {
-      running = false
-    }
-  }
-  this.then = then;
-  function then(cb, eb) {
-    return new Promise(function (resolver) {
-      function done(skipTimeout) {
-        var callback = isFulfilled ? cb : eb
-        if (typeof callback === 'function') {
-          function timeoutDone() {
-            var val;
-            try {
-              val = callback(value)
-            } catch (ex) {
-              resolver.reject(ex)
-              return next()
-            }
-            resolver.fulfill(val);
-            next(true);
-          }
-          if (skipTimeout) timeoutDone()
-          else setTimeout(timeoutDone, 0)
-        } else if (isFulfilled) {
-          resolver.fulfill(value)
-          next(skipTimeout)
-        } else {
-          resolver.reject(value)
-          next(skipTimeout)
-        }
-      }
-      waiting.push(done)
-      if (isResolved && !running) next()
-    });
-  }
-  
-  (function () {
-    function fulfill(val) {
-      if (isResolved) return
-      if (isPromise(val)) val.then(fulfill, reject)
-      else {
-        isResolved = isFulfilled = true
-        value = val
-        next()
-      }
-    }
-    function reject(err) {
-      if (isResolved) return
-      isResolved = true
-      isFulfilled = false
-      value = err
-      next()
-    }
-    var resolver = {fulfill: fulfill, reject: reject};
-    for (var i = 0; i < extensions.length; i++) {
-      extensions[i](this, resolver);
-    }
-    if (typeof fn === 'function') {
-      fn(resolver)
-    }
-  }());
-}
-function defer() {
-  var resolver
-  var promise = new Promise(function (res) { resolver = res })
-  return {resolver: resolver, promise: promise}
-}
-Promise.use = function (extension) {
-  extensions.push(extension);
+var isPromise = require('is-promise')
+
+var nextTick;
+if (typeof setImediate === 'function') nextTick = setImediate
+else if (typeof process === 'object' && process && process.nextTick) nextTick = process.nextTick
+else nextTick = function (cb) { setTimeout(cb, 0) }
+
+var extensions = [];
+
+module.exports = Promise
+function Promise(fn) {
+  if (!(this instanceof Promise)) {
+    return typeof fn === 'function' ? new Promise(fn) : defer()
+  }
+  var isResolved = false
+  var isFulfilled = false
+  var value
+  var waiting = []
+  var running = false
+
+  function next(skipTimeout) {
+    if (waiting.length) {
+      running = true
+      waiting.shift()(skipTimeout || false)
+    } else {
+      running = false
+    }
+  }
+  this.then = then;
+  function then(cb, eb) {
+    return new Promise(function (resolver) {
+      function done(skipTimeout) {
+        var callback = isFulfilled ? cb : eb
+        if (typeof callback === 'function') {
+          function timeoutDone() {
+            var val;
+            try {
+              val = callback(value)
+            } catch (ex) {
+              resolver.reject(ex)
+              return next()
+            }
+            resolver.fulfill(val);
+            next(true);
+          }
+          if (skipTimeout) timeoutDone()
+          else nextTick(timeoutDone)
+        } else if (isFulfilled) {
+          resolver.fulfill(value)
+          next(skipTimeout)
+        } else {
+          resolver.reject(value)
+          next(skipTimeout)
+        }
+      }
+      waiting.push(done)
+      if (isResolved && !running) next()
+    });
+  }
+  
+  (function () {
+    function fulfill(val) {
+      if (isResolved) return
+      if (isPromise(val)) val.then(fulfill, reject)
+      else {
+        isResolved = isFulfilled = true
+        value = val
+        next()
+      }
+    }
+    function reject(err) {
+      if (isResolved) return
+      isResolved = true
+      isFulfilled = false
+      value = err
+      next()
+    }
+    var resolver = {fulfill: fulfill, reject: reject};
+    for (var i = 0; i < extensions.length; i++) {
+      extensions[i](this, resolver);
+    }
+    if (typeof fn === 'function') {
+      try {
+        fn(resolver)
+      } catch (ex) {
+        resolver.reject(ex);
+      }
+    }
+  }());
+}
+function defer() {
+  var resolver
+  var promise = new Promise(function (res) { resolver = res })
+  return {resolver: resolver, promise: promise}
+}
+Promise.use = function (extension) {
+  extensions.push(extension);
 };