Website/node_modules/lodash._getnative/index.js
2015-12-02 18:21:44 -05:00

138 lines
3.8 KiB
JavaScript

/**
* lodash 3.9.1 (Custom Build) <https://lodash.com/>
* Build: `lodash modern modularize exports="npm" -o ./`
* Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
* Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
* Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
* Available under MIT license <https://lodash.com/license>
*/
/** `Object#toString` result references. */
var funcTag = '[object Function]';
/** Used to detect host constructors (Safari > 5). */
var reIsHostCtor = /^\[object .+?Constructor\]$/;
/**
* Checks if `value` is object-like.
*
* @private
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is object-like, else `false`.
*/
function isObjectLike(value) {
return !!value && typeof value == 'object';
}
/** Used for native method references. */
var objectProto = Object.prototype;
/** Used to resolve the decompiled source of functions. */
var fnToString = Function.prototype.toString;
/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;
/**
* Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
* of values.
*/
var objToString = objectProto.toString;
/** Used to detect if a method is native. */
var reIsNative = RegExp('^' +
fnToString.call(hasOwnProperty).replace(/[\\^$.*+?()[\]{}|]/g, '\\$&')
.replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
);
/**
* Gets the native function at `key` of `object`.
*
* @private
* @param {Object} object The object to query.
* @param {string} key The key of the method to get.
* @returns {*} Returns the function if it's native, else `undefined`.
*/
function getNative(object, key) {
var value = object == null ? undefined : object[key];
return isNative(value) ? value : undefined;
}
/**
* Checks if `value` is classified as a `Function` object.
*
* @static
* @memberOf _
* @category Lang
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
* @example
*
* _.isFunction(_);
* // => true
*
* _.isFunction(/abc/);
* // => false
*/
function isFunction(value) {
// The use of `Object#toString` avoids issues with the `typeof` operator
// in older versions of Chrome and Safari which return 'function' for regexes
// and Safari 8 equivalents which return 'object' for typed array constructors.
return isObject(value) && objToString.call(value) == funcTag;
}
/**
* Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`.
* (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
*
* @static
* @memberOf _
* @category Lang
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is an object, else `false`.
* @example
*
* _.isObject({});
* // => true
*
* _.isObject([1, 2, 3]);
* // => true
*
* _.isObject(1);
* // => false
*/
function isObject(value) {
// Avoid a V8 JIT bug in Chrome 19-20.
// See https://code.google.com/p/v8/issues/detail?id=2291 for more details.
var type = typeof value;
return !!value && (type == 'object' || type == 'function');
}
/**
* Checks if `value` is a native function.
*
* @static
* @memberOf _
* @category Lang
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is a native function, else `false`.
* @example
*
* _.isNative(Array.prototype.push);
* // => true
*
* _.isNative(_);
* // => false
*/
function isNative(value) {
if (value == null) {
return false;
}
if (isFunction(value)) {
return reIsNative.test(fnToString.call(value));
}
return isObjectLike(value) && reIsHostCtor.test(value);
}
module.exports = getNative;