1
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var root = require('./_root'),
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2
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toInteger = require('./toInteger'),
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3
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toNumber = require('./toNumber'),
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4
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toString = require('./toString');
|
5
|
|
6
|
/* Built-in method references for those with the same name as other `lodash` methods. */
|
7
|
var nativeIsFinite = root.isFinite,
|
8
|
nativeMin = Math.min;
|
9
|
|
10
|
/**
|
11
|
* Creates a function like `_.round`.
|
12
|
*
|
13
|
* @private
|
14
|
* @param {string} methodName The name of the `Math` method to use when rounding.
|
15
|
* @returns {Function} Returns the new round function.
|
16
|
*/
|
17
|
function createRound(methodName) {
|
18
|
var func = Math[methodName];
|
19
|
return function(number, precision) {
|
20
|
number = toNumber(number);
|
21
|
precision = precision == null ? 0 : nativeMin(toInteger(precision), 292);
|
22
|
if (precision && nativeIsFinite(number)) {
|
23
|
// Shift with exponential notation to avoid floating-point issues.
|
24
|
// See [MDN](https://mdn.io/round#Examples) for more details.
|
25
|
var pair = (toString(number) + 'e').split('e'),
|
26
|
value = func(pair[0] + 'e' + (+pair[1] + precision));
|
27
|
|
28
|
pair = (toString(value) + 'e').split('e');
|
29
|
return +(pair[0] + 'e' + (+pair[1] - precision));
|
30
|
}
|
31
|
return func(number);
|
32
|
};
|
33
|
}
|
34
|
|
35
|
module.exports = createRound;
|