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87 lines
2.7 KiB
JavaScript
87 lines
2.7 KiB
JavaScript
/**
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* lodash 3.1.1 (Custom Build) <https://lodash.com/>
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* Build: `lodash modern modularize exports="npm" -o ./`
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* Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
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* Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
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* Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
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* Available under MIT license <https://lodash.com/license>
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*/
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var baseAt = require('lodash._baseat'),
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baseFlatten = require('lodash._baseflatten'),
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toIterable = require('lodash._toiterable'),
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restParam = require('lodash.restparam');
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/**
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* Used as the [maximum length](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.max_safe_integer)
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* of an array-like value.
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*/
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var MAX_SAFE_INTEGER = Math.pow(2, 53) - 1;
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/**
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* The base implementation of `_.property` without support for deep paths.
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*
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* @private
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* @param {string} key The key of the property to get.
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* @returns {Function} Returns the new function.
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*/
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function baseProperty(key) {
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return function(object) {
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return object == null ? undefined : object[key];
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};
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}
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/**
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* Gets the "length" property value of `object`.
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*
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* **Note:** This function is used to avoid a [JIT bug](https://bugs.webkit.org/show_bug.cgi?id=142792)
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* in Safari on iOS 8.1 ARM64.
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*
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* @private
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* @param {Object} object The object to query.
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* @returns {*} Returns the "length" value.
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*/
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var getLength = baseProperty('length');
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/**
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* Checks if `value` is a valid array-like length.
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*
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* **Note:** This function is based on [`ToLength`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength).
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*
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* @private
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* @param {*} value The value to check.
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* @returns {boolean} Returns `true` if `value` is a valid length, else `false`.
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*/
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function isLength(value) {
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return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
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}
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/**
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* Creates an array of elements corresponding to the given keys, or indexes,
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* of `collection`. Keys may be specified as individual arguments or as arrays
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* of keys.
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*
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* @static
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* @memberOf _
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* @category Collection
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* @param {Array|Object|string} collection The collection to iterate over.
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* @param {...(number|number[]|string|string[])} [props] The property names
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* or indexes of elements to pick, specified individually or in arrays.
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* @returns {Array} Returns the new array of picked elements.
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* @example
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*
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* _.at(['a', 'b', 'c'], [0, 2]);
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* // => ['a', 'c']
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*
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* _.at(['barney', 'fred', 'pebbles'], 0, 2);
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* // => ['barney', 'pebbles']
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*/
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var at = restParam(function(collection, props) {
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var length = collection ? getLength(collection) : 0;
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if (isLength(length)) {
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collection = toIterable(collection);
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}
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return baseAt(collection, baseFlatten(props));
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});
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module.exports = at;
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