Added this to the basic fall function.

README.md

@@ -30,7 +30,7 @@ npm install fastfall --save
 ## Usage
 
 ```js
-var fall = require('./')()
+var fall = require('fastfall')()
 
 fall([
   function a (cb) {
@@ -49,11 +49,11 @@ fall([
   })
 ```
 
-You can also set `this` in the functions:
+You can also set `this` when you create a fall:
 
 ```js
 var that = { hello: 'world' }
-var fall = require('./')(that)
+var fall = require('fastfall')(that)
 
 fall([
   function a (cb) {
@@ -73,6 +73,28 @@ fall([
   })
 ```
 
+You can also set `this` when you run a task:
+
+var that = { hello: 'world' }
+var fall = require('fastfall')()
+
+fall(that, [
+  function a (cb) {
+    console.log(this)
+    console.log('called a')
+    cb(null, 'a')
+  },
+  function b (a, cb) {
+    console.log('called b with:', a)
+    cb(null, 'a', 'b')
+  },
+  function c (a, b, cb) {
+    console.log('called c with:', a, b)
+    cb(null, 'a', 'b', 'c')
+  }], function result (err, a, b, c) {
+    console.log('result arguments', arguments)
+  })
+
 ### Compile a waterfall
 
 ```js

fall.js

@@ -9,7 +9,7 @@ function fastfall (context, template) {
     context = null
   }
 
-  var head = new Holder(context, release)
+  var head = new Holder(release)
   var tail = head
 
   return template ? compiled : fall
@@ -20,7 +20,7 @@ function fastfall (context, template) {
     if (holder.next) {
       head = holder.next
     } else {
-      head = new Holder(context, release)
+      head = new Holder(release)
       tail = head
     }
 
@@ -29,11 +29,18 @@ function fastfall (context, template) {
     return holder
   }
 
-  function fall (list, done) {
+  function fall () {
     var current = next()
 
-    current.list = list
-    current.callback = done
+    if (arguments.length === 3) {
+      current.context = arguments[0]
+      current.list = arguments[1]
+      current.callback = arguments[2] || noop
+    } else {
+      current.context = context
+      current.list = arguments[0]
+      current.callback = arguments[1] || noop
+    }
 
     current.work()
   }
@@ -57,18 +64,20 @@ function fastfall (context, template) {
       args[i + 1] = arguments[i]
     }
 
-    current.callback = arguments[i]
+    current.context = context
+    current.callback = arguments[i] || noop
 
     current.work.apply(null, args)
   }
 }
 
 function noop () {}
 
-function Holder (context, release) {
+function Holder (release) {
   this.list = empty
   this.callback = noop
   this.count = 0
+  this.context = undefined
 
   var that = this
 
@@ -86,12 +95,13 @@ function Holder (context, release) {
         args[i - 1] = arguments[i]
       }
       args[args.length] = work
-      that.list[that.count++].apply(context, args)
+      that.list[that.count++].apply(that.context, args)
     } else {
       for (i = 0; i < arguments.length; i++) {
         args[i] = arguments[i]
       }
-      that.callback.apply(context, args)
+      that.callback.apply(that.context, args)
+      that.context = undefined
       that.list = empty
       that.count = 0
       release(that)

test.js

@@ -100,7 +100,7 @@ test('set this', function (t) {
 })
 
 test('set this in compiled mode', function (t) {
-  t.plan(3)
+  t.plan(4)
 
   var that = {}
   var fall = fastfall(that, [
@@ -113,5 +113,24 @@ test('set this in compiled mode', function (t) {
   fall(42, function result (err, a, b, c) {
     t.error(err, 'no error')
     t.equal(a, 42, 'result function 2nd arg matches')
+    t.equal(this, that, 'this is set')
+  })
+})
+
+test('set this for a normal fall', function (t) {
+  t.plan(4)
+
+  var that = {}
+  var fall = fastfall()
+
+  fall(that, [
+    function a (cb) {
+      t.equal(this, that, 'this is set')
+      cb(null, 'a')
+    }
+  ], function result (err, a) {
+    t.error(err, 'no error')
+    t.equal(this, that, 'this is set')
+    t.equal(a, 'a', 'result function 2nd arg matches')
   })
 })