mirror of
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100 lines
3.1 KiB
JavaScript
100 lines
3.1 KiB
JavaScript
/**
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* lodash 3.0.2 (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 1.7.0 <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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/**
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* Used as the maximum length of an array-like value.
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* See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.max_safe_integer)
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* for more details.
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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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* Checks if `value` is a valid array-like index.
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*
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* @private
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* @param {*} value The value to check.
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* @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
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* @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
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*/
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function isIndex(value, length) {
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value = +value;
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length = length == null ? MAX_SAFE_INTEGER : length;
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return value > -1 && value % 1 == 0 && value < length;
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}
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/**
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* Checks if the provided arguments are from an iteratee call.
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*
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* @private
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* @param {*} value The potential iteratee value argument.
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* @param {*} index The potential iteratee index or key argument.
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* @param {*} object The potential iteratee object argument.
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* @returns {boolean} Returns `true` if the arguments are from an iteratee call, else `false`.
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*/
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function isIterateeCall(value, index, object) {
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if (!isObject(object)) {
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return false;
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}
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var type = typeof index;
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if (type == 'number') {
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var length = object.length,
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prereq = isLength(length) && isIndex(index, length);
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} else {
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prereq = type == 'string' && index in object;
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}
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var other = object[index];
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return prereq && (value === value ? value === other : other !== other);
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}
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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 ES `ToLength`. See the
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* [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength)
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* for more details.
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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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* Checks if `value` is the language type of `Object`.
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* (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
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*
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* **Note:** See the [ES5 spec](https://es5.github.io/#x8) for more details.
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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 an object, else `false`.
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* @example
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*
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* _.isObject({});
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* // => true
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*
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* _.isObject([1, 2, 3]);
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* // => true
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*
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* _.isObject(1);
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* // => false
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*/
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function isObject(value) {
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// Avoid a V8 JIT bug in Chrome 19-20.
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// See https://code.google.com/p/v8/issues/detail?id=2291 for more details.
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var type = typeof value;
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return type == 'function' || (value && type == 'object') || false;
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}
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module.exports = isIterateeCall;
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