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