lodash/lodash._createset/index.js

/**
 * lodash 4.0.2 (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o ./`
 * Copyright jQuery Foundation and other contributors <https://jquery.org/>
 * Released under MIT license <https://lodash.com/license>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 */

/** `Object#toString` result references. */
var funcTag = '[object Function]',
    genTag = '[object GeneratorFunction]';

/**
 * Used to match `RegExp`
 * [syntax characters](http://ecma-international.org/ecma-262/6.0/#sec-patterns).
 */
var reRegExpChar = /[\\^$.*+?()[\]{}|]/g;

/** Used to detect host constructors (Safari). */
var reIsHostCtor = /^\[object .+?Constructor\]$/;

/** Used to determine if values are of the language type `Object`. */
var objectTypes = {
  'function': true,
  'object': true
};

/** Detect free variable `exports`. */
var freeExports = (objectTypes[typeof exports] && exports && !exports.nodeType)
  ? exports
  : undefined;

/** Detect free variable `module`. */
var freeModule = (objectTypes[typeof module] && module && !module.nodeType)
  ? module
  : undefined;

/** Detect free variable `global` from Node.js. */
var freeGlobal = checkGlobal(freeExports && freeModule && typeof global == 'object' && global);

/** Detect free variable `self`. */
var freeSelf = checkGlobal(objectTypes[typeof self] && self);

/** Detect free variable `window`. */
var freeWindow = checkGlobal(objectTypes[typeof window] && window);

/** Detect `this` as the global object. */
var thisGlobal = checkGlobal(objectTypes[typeof this] && this);

/**
 * Used as a reference to the global object.
 *
 * The `this` value is used if it's the global object to avoid Greasemonkey's
 * restricted `window` object, otherwise the `window` object is used.
 */
var root = freeGlobal ||
  ((freeWindow !== (thisGlobal && thisGlobal.window)) && freeWindow) ||
    freeSelf || thisGlobal || Function('return this')();

/**
 * Checks if `value` is a global object.
 *
 * @private
 * @param {*} value The value to check.
 * @returns {null|Object} Returns `value` if it's a global object, else `null`.
 */
function checkGlobal(value) {
  return (value && value.Object === Object) ? value : null;
}

/**
 * Checks if `value` is a host object in IE < 9.
 *
 * @private
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a host object, else `false`.
 */
function isHostObject(value) {
  // Many host objects are `Object` objects that can coerce to strings
  // despite having improperly defined `toString` methods.
  var result = false;
  if (value != null && typeof value.toString != 'function') {
    try {
      result = !!(value + '');
    } catch (e) {}
  }
  return result;
}

/** Used for built-in method references. */
var objectProto = Object.prototype;

/** Used to resolve the decompiled source of functions. */
var funcToString = 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 objectToString = objectProto.toString;

/** Used to detect if a method is native. */
var reIsNative = RegExp('^' +
  funcToString.call(hasOwnProperty).replace(reRegExpChar, '\\$&')
  .replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
);

/* Built-in method references that are verified to be native. */
var Set = getNative(root, 'Set');

/**
 * Creates a set of `values`.
 *
 * @private
 * @param {Array} values The values to add to the set.
 * @returns {Object} Returns the new set.
 */
var createSet = !(Set && new Set([1, 2]).size === 2) ? noop : function(values) {
  return new Set(values);
};

/**
 * 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[key];
  return isNative(value) ? value : undefined;
}

/**
 * Converts `func` to its source code.
 *
 * @private
 * @param {Function} func The function to process.
 * @returns {string} Returns the source code.
 */
function toSource(func) {
  if (func != null) {
    try {
      return funcToString.call(func);
    } catch (e) {}
    try {
      return (func + '');
    } catch (e) {}
  }
  return '';
}

/**
 * Checks if `value` is classified as a `Function` object.
 *
 * @static
 * @memberOf _
 * @since 0.1.0
 * @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 Safari 8 which returns 'object' for typed array and weak map constructors,
  // and PhantomJS 1.9 which returns 'function' for `NodeList` instances.
  var tag = isObject(value) ? objectToString.call(value) : '';
  return tag == funcTag || tag == genTag;
}

/**
 * Checks if `value` is the
 * [language type](http://www.ecma-international.org/ecma-262/6.0/#sec-ecmascript-language-types)
 * of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
 *
 * @static
 * @memberOf _
 * @since 0.1.0
 * @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(_.noop);
 * // => true
 *
 * _.isObject(null);
 * // => false
 */
function isObject(value) {
  var type = typeof value;
  return !!value && (type == 'object' || type == 'function');
}

/**
 * Checks if `value` is a native function.
 *
 * @static
 * @memberOf _
 * @since 3.0.0
 * @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 (!isObject(value)) {
    return false;
  }
  var pattern = (isFunction(value) || isHostObject(value)) ? reIsNative : reIsHostCtor;
  return pattern.test(toSource(value));
}

/**
 * A no-operation function that returns `undefined` regardless of the
 * arguments it receives.
 *
 * @static
 * @memberOf _
 * @since 2.3.0
 * @category Util
 * @example
 *
 * var object = { 'user': 'fred' };
 *
 * _.noop(object) === undefined;
 * // => true
 */
function noop() {
  // No operation performed.
}

module.exports = createSet;