Gazebo_simulation-Frontend/node_modules/thunky/index.js

56 lines
1.0 KiB
JavaScript

'use strict'
var nextTick = nextTickArgs
process.nextTick(upgrade, 42) // pass 42 and see if upgrade is called with it
module.exports = thunky
function thunky (fn) {
var state = run
return thunk
function thunk (callback) {
state(callback || noop)
}
function run (callback) {
var stack = [callback]
state = wait
fn(done)
function wait (callback) {
stack.push(callback)
}
function done (err) {
var args = arguments
state = isError(err) ? run : finished
while (stack.length) finished(stack.shift())
function finished (callback) {
nextTick(apply, callback, args)
}
}
}
}
function isError (err) { // inlined from util so this works in the browser
return Object.prototype.toString.call(err) === '[object Error]'
}
function noop () {}
function apply (callback, args) {
callback.apply(null, args)
}
function upgrade (val) {
if (val === 42) nextTick = process.nextTick
}
function nextTickArgs (fn, a, b) {
process.nextTick(function () {
fn(a, b)
})
}