Function _restParam

public/javascripts/async.js:157–177

(func, startIndex)

    // This accumulates the arguments passed into an array, after a given index.
    // From underscore.js (https://github.com/jashkenas/underscore/pull/2140).
    function _restParam(func, startIndex) {
        startIndex = startIndex == null ? func.length - 1 : +startIndex;
        return function() {
            var length = Math.max(arguments.length - startIndex, 0);
            var rest = Array(length);
            for (var index = 0; index < length; index++) {
                rest[index] = arguments[index + startIndex];
            }
            switch (startIndex) {
                case 0: return func.call(this, rest);
                case 1: return func.call(this, arguments[0], rest);
            }
            // Currently unused but handle cases outside of the switch statement:
            // var args = Array(startIndex + 1);
            // for (index = 0; index < startIndex; index++) {
            //     args[index] = arguments[index];
            // }
            // args[startIndex] = rest;
            // return func.apply(this, args);
        };
    }

    function _withoutIndex(iterator) {
        return function (value, index, callback) {