mirror of
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141 lines
3.4 KiB
JavaScript
141 lines
3.4 KiB
JavaScript
/**
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* lodash 3.2.0 (Custom Build) <https://lodash.com/>
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* Build: `lodash modularize exports="npm" -o ./`
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* Copyright 2012-2016 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 2009-2016 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 root = require('lodash._root');
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/** Used as references for various `Number` constants. */
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var INFINITY = 1 / 0;
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/** `Object#toString` result references. */
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var symbolTag = '[object Symbol]';
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/** Used for built-in method references. */
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var objectProto = Object.prototype;
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/** Used to generate unique IDs. */
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var idCounter = 0;
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/**
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* Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
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* of values.
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*/
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var objectToString = objectProto.toString;
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/** Built-in value references. */
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var Symbol = root.Symbol;
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/** Used to convert symbols to primitives and strings. */
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var symbolProto = Symbol ? Symbol.prototype : undefined,
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symbolToString = Symbol ? symbolProto.toString : undefined;
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/**
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* Checks if `value` is object-like. A value is object-like if it's not `null`
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* and has a `typeof` result of "object".
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*
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* @static
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* @memberOf _
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* @category Lang
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* @param {*} value The value to check.
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* @returns {boolean} Returns `true` if `value` is object-like, else `false`.
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* @example
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*
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* _.isObjectLike({});
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* // => true
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*
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* _.isObjectLike([1, 2, 3]);
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* // => true
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*
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* _.isObjectLike(_.noop);
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* // => false
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*
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* _.isObjectLike(null);
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* // => false
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*/
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function isObjectLike(value) {
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return !!value && typeof value == 'object';
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}
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/**
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* Checks if `value` is classified as a `Symbol` primitive or object.
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*
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* @static
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* @memberOf _
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* @category Lang
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* @param {*} value The value to check.
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* @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
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* @example
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*
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* _.isSymbol(Symbol.iterator);
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* // => true
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*
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* _.isSymbol('abc');
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* // => false
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*/
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function isSymbol(value) {
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return typeof value == 'symbol' ||
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(isObjectLike(value) && objectToString.call(value) == symbolTag);
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}
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/**
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* Converts `value` to a string if it's not one. An empty string is returned
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* for `null` and `undefined` values. The sign of `-0` is preserved.
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*
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* @static
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* @memberOf _
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* @category Lang
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* @param {*} value The value to process.
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* @returns {string} Returns the string.
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* @example
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*
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* _.toString(null);
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* // => ''
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*
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* _.toString(-0);
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* // => '-0'
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*
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* _.toString([1, 2, 3]);
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* // => '1,2,3'
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*/
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function toString(value) {
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// Exit early for strings to avoid a performance hit in some environments.
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if (typeof value == 'string') {
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return value;
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}
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if (value == null) {
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return '';
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}
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if (isSymbol(value)) {
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return Symbol ? symbolToString.call(value) : '';
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}
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var result = (value + '');
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return (result == '0' && (1 / value) == -INFINITY) ? '-0' : result;
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}
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/**
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* Generates a unique ID. If `prefix` is provided the ID is appended to it.
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*
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* @static
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* @memberOf _
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* @category Util
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* @param {string} [prefix] The value to prefix the ID with.
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* @returns {string} Returns the unique ID.
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* @example
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*
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* _.uniqueId('contact_');
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* // => 'contact_104'
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*
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* _.uniqueId();
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* // => '105'
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*/
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function uniqueId(prefix) {
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var id = ++idCounter;
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return toString(prefix) + id;
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}
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module.exports = uniqueId;
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