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/*!
* Sync/Async forEach
* https://github.com/cowboy/javascript-sync-async-foreach
*
* Copyright (c) 2012 "Cowboy" Ben Alman
* Licensed under the MIT license.
* http://benalman.com/about/license/
*/
(function(exports) {
// Iterate synchronously or asynchronously.
exports.forEach = function(arr, eachFn, doneFn) {
var i = -1;
// Resolve array length to a valid (ToUint32) number.
var len = arr.length >>> 0;
// This IIFE is called once now, and then again, by name, for each loop
// iteration.
(function next(result) {
// This flag will be set to true if `this.async` is called inside the
// eachFn` callback.
var async;
// Was false returned from the `eachFn` callback or passed to the
// `this.async` done function?
var abort = result === false;
// Increment counter variable and skip any indices that don't exist. This
// allows sparse arrays to be iterated.
do { ++i; } while (!(i in arr) && i !== len);
// Exit if result passed to `this.async` done function or returned from
// the `eachFn` callback was false, or when done iterating.
if (abort || i === len) {
// If a `doneFn` callback was specified, invoke that now. Pass in a
// boolean value representing "not aborted" state along with the array.
if (doneFn) {
doneFn(!abort, arr);
}
return;
}
// Invoke the `eachFn` callback, setting `this` inside the callback to a
// custom object that contains one method, and passing in the array item,
// index, and the array.
result = eachFn.call({
// If `this.async` is called inside the `eachFn` callback, set the async
// flag and return a function that can be used to continue iterating.
async: function() {
async = true;
return next;
}
}, arr[i], i, arr);
// If the async flag wasn't set, continue by calling `next` synchronously,
// passing in the result of the `eachFn` callback.
if (!async) {
next(result);
}
}());
};
}(typeof exports === "object" && exports || this));