1
|
'use strict'
|
2
|
|
3
|
var nextTick = nextTickArgs
|
4
|
process.nextTick(upgrade, 42) // pass 42 and see if upgrade is called with it
|
5
|
|
6
|
module.exports = thunky
|
7
|
|
8
|
function thunky (fn) {
|
9
|
var state = run
|
10
|
return thunk
|
11
|
|
12
|
function thunk (callback) {
|
13
|
state(callback || noop)
|
14
|
}
|
15
|
|
16
|
function run (callback) {
|
17
|
var stack = [callback]
|
18
|
state = wait
|
19
|
fn(done)
|
20
|
|
21
|
function wait (callback) {
|
22
|
stack.push(callback)
|
23
|
}
|
24
|
|
25
|
function done (err) {
|
26
|
var args = arguments
|
27
|
state = isError(err) ? run : finished
|
28
|
while (stack.length) finished(stack.shift())
|
29
|
|
30
|
function finished (callback) {
|
31
|
nextTick(apply, callback, args)
|
32
|
}
|
33
|
}
|
34
|
}
|
35
|
}
|
36
|
|
37
|
function isError (err) { // inlined from util so this works in the browser
|
38
|
return Object.prototype.toString.call(err) === '[object Error]'
|
39
|
}
|
40
|
|
41
|
function noop () {}
|
42
|
|
43
|
function apply (callback, args) {
|
44
|
callback.apply(null, args)
|
45
|
}
|
46
|
|
47
|
function upgrade (val) {
|
48
|
if (val === 42) nextTick = process.nextTick
|
49
|
}
|
50
|
|
51
|
function nextTickArgs (fn, a, b) {
|
52
|
process.nextTick(function () {
|
53
|
fn(a, b)
|
54
|
})
|
55
|
}
|