import apply from './_apply.js'; import arrayPush from './_arrayPush.js'; import baseRest from './_baseRest.js'; import castSlice from './_castSlice.js'; import toInteger from './toInteger.js'; /** Error message constants. */ var FUNC_ERROR_TEXT = 'Expected a function'; /* Built-in method references for those with the same name as other `lodash` methods. */ var nativeMax = Math.max; /** * Creates a function that invokes `func` with the `this` binding of the * create function and an array of arguments much like * [`Function#apply`](http://www.ecma-international.org/ecma-262/7.0/#sec-function.prototype.apply). * * **Note:** This method is based on the * [spread operator](https://mdn.io/spread_operator). * * @static * @memberOf _ * @since 3.2.0 * @category Function * @param {Function} func The function to spread arguments over. * @param {number} [start=0] The start position of the spread. * @returns {Function} Returns the new function. * @example * * var say = _.spread(function(who, what) { * return who + ' says ' + what; * }); * * say(['fred', 'hello']); * // => 'fred says hello' * * var numbers = Promise.all([ * Promise.resolve(40), * Promise.resolve(36) * ]); * * numbers.then(_.spread(function(x, y) { * return x + y; * })); * // => a Promise of 76 */ function spread(func, start) { if (typeof func != 'function') { throw new TypeError(FUNC_ERROR_TEXT); } start = start == null ? 0 : nativeMax(toInteger(start), 0); return baseRest(function(args) { var array = args[start], otherArgs = castSlice(args, 0, start); if (array) { arrayPush(otherArgs, array); } return apply(func, this, otherArgs); }); } export default spread;