1
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var apply = require('./_apply'),
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2
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arrayPush = require('./_arrayPush'),
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3
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baseRest = require('./_baseRest'),
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4
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castSlice = require('./_castSlice'),
|
5
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toInteger = require('./toInteger');
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6
|
|
7
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/** Error message constants. */
|
8
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var FUNC_ERROR_TEXT = 'Expected a function';
|
9
|
|
10
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/* Built-in method references for those with the same name as other `lodash` methods. */
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11
|
var nativeMax = Math.max;
|
12
|
|
13
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/**
|
14
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* Creates a function that invokes `func` with the `this` binding of the
|
15
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* create function and an array of arguments much like
|
16
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* [`Function#apply`](http://www.ecma-international.org/ecma-262/7.0/#sec-function.prototype.apply).
|
17
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*
|
18
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* **Note:** This method is based on the
|
19
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* [spread operator](https://mdn.io/spread_operator).
|
20
|
*
|
21
|
* @static
|
22
|
* @memberOf _
|
23
|
* @since 3.2.0
|
24
|
* @category Function
|
25
|
* @param {Function} func The function to spread arguments over.
|
26
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* @param {number} [start=0] The start position of the spread.
|
27
|
* @returns {Function} Returns the new function.
|
28
|
* @example
|
29
|
*
|
30
|
* var say = _.spread(function(who, what) {
|
31
|
* return who + ' says ' + what;
|
32
|
* });
|
33
|
*
|
34
|
* say(['fred', 'hello']);
|
35
|
* // => 'fred says hello'
|
36
|
*
|
37
|
* var numbers = Promise.all([
|
38
|
* Promise.resolve(40),
|
39
|
* Promise.resolve(36)
|
40
|
* ]);
|
41
|
*
|
42
|
* numbers.then(_.spread(function(x, y) {
|
43
|
* return x + y;
|
44
|
* }));
|
45
|
* // => a Promise of 76
|
46
|
*/
|
47
|
function spread(func, start) {
|
48
|
if (typeof func != 'function') {
|
49
|
throw new TypeError(FUNC_ERROR_TEXT);
|
50
|
}
|
51
|
start = start == null ? 0 : nativeMax(toInteger(start), 0);
|
52
|
return baseRest(function(args) {
|
53
|
var array = args[start],
|
54
|
otherArgs = castSlice(args, 0, start);
|
55
|
|
56
|
if (array) {
|
57
|
arrayPush(otherArgs, array);
|
58
|
}
|
59
|
return apply(func, this, otherArgs);
|
60
|
});
|
61
|
}
|
62
|
|
63
|
module.exports = spread;
|