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Member "Atom/resources/app/apm/node_modules/slide/lib/async-map.js" (7 Feb 2017, 1471 Bytes) of archive /windows/misc/atom-windows.zip:


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    1 
    2 /*
    3 usage:
    4 
    5 // do something to a list of things
    6 asyncMap(myListOfStuff, function (thing, cb) { doSomething(thing.foo, cb) }, cb)
    7 // do more than one thing to each item
    8 asyncMap(list, fooFn, barFn, cb)
    9 
   10 */
   11 
   12 module.exports = asyncMap
   13 
   14 function asyncMap () {
   15   var steps = Array.prototype.slice.call(arguments)
   16     , list = steps.shift() || []
   17     , cb_ = steps.pop()
   18   if (typeof cb_ !== "function") throw new Error(
   19     "No callback provided to asyncMap")
   20   if (!list) return cb_(null, [])
   21   if (!Array.isArray(list)) list = [list]
   22   var n = steps.length
   23     , data = [] // 2d array
   24     , errState = null
   25     , l = list.length
   26     , a = l * n
   27   if (!a) return cb_(null, [])
   28   function cb (er) {
   29     if (er && !errState) errState = er
   30 
   31     var argLen = arguments.length
   32     for (var i = 1; i < argLen; i ++) if (arguments[i] !== undefined) {
   33       data[i - 1] = (data[i - 1] || []).concat(arguments[i])
   34     }
   35     // see if any new things have been added.
   36     if (list.length > l) {
   37       var newList = list.slice(l)
   38       a += (list.length - l) * n
   39       l = list.length
   40       process.nextTick(function () {
   41         newList.forEach(function (ar) {
   42           steps.forEach(function (fn) { fn(ar, cb) })
   43         })
   44       })
   45     }
   46 
   47     if (--a === 0) cb_.apply(null, [errState].concat(data))
   48   }
   49   // expect the supplied cb function to be called
   50   // "n" times for each thing in the array.
   51   list.forEach(function (ar) {
   52     steps.forEach(function (fn) { fn(ar, cb) })
   53   })
   54 }