path: root/node_modules/lodash._baseclone/index.js

/**
 * lodash 3.2.1 (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>
 */
var arrayCopy = require('lodash._arraycopy'),
    arrayEach = require('lodash._arrayeach'),
    baseAssign = require('lodash._baseassign'),
    baseFor = require('lodash._basefor'),
    getNative = require('lodash._getnative'),
    isArray = require('lodash.isarray'),
    keys = require('lodash.keys');

/** `Object#toString` result references. */
var argsTag = '[object Arguments]',
    arrayTag = '[object Array]',
    boolTag = '[object Boolean]',
    dateTag = '[object Date]',
    errorTag = '[object Error]',
    funcTag = '[object Function]',
    mapTag = '[object Map]',
    numberTag = '[object Number]',
    objectTag = '[object Object]',
    regexpTag = '[object RegExp]',
    setTag = '[object Set]',
    stringTag = '[object String]',
    weakMapTag = '[object WeakMap]';

var arrayBufferTag = '[object ArrayBuffer]',
    float32Tag = '[object Float32Array]',
    float64Tag = '[object Float64Array]',
    int8Tag = '[object Int8Array]',
    int16Tag = '[object Int16Array]',
    int32Tag = '[object Int32Array]',
    uint8Tag = '[object Uint8Array]',
    uint8ClampedTag = '[object Uint8ClampedArray]',
    uint16Tag = '[object Uint16Array]',
    uint32Tag = '[object Uint32Array]';

/** Used to match `RegExp` flags from their coerced string values. */
var reFlags = /\w*$/;

/** Used to identify `toStringTag` values supported by `_.clone`. */
var cloneableTags = {};
cloneableTags[argsTag] = cloneableTags[arrayTag] =
cloneableTags[arrayBufferTag] = cloneableTags[boolTag] =
cloneableTags[dateTag] = cloneableTags[float32Tag] =
cloneableTags[float64Tag] = cloneableTags[int8Tag] =
cloneableTags[int16Tag] = cloneableTags[int32Tag] =
cloneableTags[numberTag] = cloneableTags[objectTag] =
cloneableTags[regexpTag] = cloneableTags[stringTag] =
cloneableTags[uint8Tag] = cloneableTags[uint8ClampedTag] =
cloneableTags[uint16Tag] = cloneableTags[uint32Tag] = true;
cloneableTags[errorTag] = cloneableTags[funcTag] =
cloneableTags[mapTag] = cloneableTags[setTag] =
cloneableTags[weakMapTag] = false;

/** Used for native method references. */
var objectProto = Object.prototype;

/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;

/**
 * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
 * of values.
 */
var objToString = objectProto.toString;

/** Native method references. */
var ArrayBuffer = getNative(global, 'ArrayBuffer'),
    bufferSlice = getNative(ArrayBuffer && new ArrayBuffer(0), 'slice'),
    floor = Math.floor,
    Uint8Array = getNative(global, 'Uint8Array');

/** Used to clone array buffers. */
var Float64Array = (function() {
  // Safari 5 errors when using an array buffer to initialize a typed array
  // where the array buffer's `byteLength` is not a multiple of the typed
  // array's `BYTES_PER_ELEMENT`.
  try {
    var func = getNative(global, 'Float64Array'),
        result = new func(new ArrayBuffer(10), 0, 1) && func;
  } catch(e) {}
  return result || null;
}());

/** Used as the size, in bytes, of each `Float64Array` element. */
var FLOAT64_BYTES_PER_ELEMENT = Float64Array ? Float64Array.BYTES_PER_ELEMENT : 0;

/**
 * The base implementation of `_.clone` without support for argument juggling
 * and `this` binding `customizer` functions.
 *
 * @private
 * @param {*} value The value to clone.
 * @param {boolean} [isDeep] Specify a deep clone.
 * @param {Function} [customizer] The function to customize cloning values.
 * @param {string} [key] The key of `value`.
 * @param {Object} [object] The object `value` belongs to.
 * @param {Array} [stackA=[]] Tracks traversed source objects.
 * @param {Array} [stackB=[]] Associates clones with source counterparts.
 * @returns {*} Returns the cloned value.
 */
function baseClone(value, isDeep, customizer, key, object, stackA, stackB) {
  var result;
  if (customizer) {
    result = object ? customizer(value, key, object) : customizer(value);
  }
  if (result !== undefined) {
    return result;
  }
  if (!isObject(value)) {
    return value;
  }
  var isArr = isArray(value);
  if (isArr) {
    result = initCloneArray(value);
    if (!isDeep) {
      return arrayCopy(value, result);
    }
  } else {
    var tag = objToString.call(value),
        isFunc = tag == funcTag;

    if (tag == objectTag || tag == argsTag || (isFunc && !object)) {
      result = initCloneObject(isFunc ? {} : value);
      if (!isDeep) {
        return baseAssign(result, value);
      }
    } else {
      return cloneableTags[tag]
        ? initCloneByTag(value, tag, isDeep)
        : (object ? value : {});
    }
  }
  // Check for circular references and return corresponding clone.
  stackA || (stackA = []);
  stackB || (stackB = []);

  var length = stackA.length;
  while (length--) {
    if (stackA[length] == value) {
      return stackB[length];
    }
  }
  // Add the source value to the stack of traversed objects and associate it with its clone.
  stackA.push(value);
  stackB.push(result);

  // Recursively populate clone (susceptible to call stack limits).
  (isArr ? arrayEach : baseForOwn)(value, function(subValue, key) {
    result[key] = baseClone(subValue, isDeep, customizer, key, value, stackA, stackB);
  });
  return result;
}

/**
 * The base implementation of `_.forOwn` without support for callback
 * shorthands and `this` binding.
 *
 * @private
 * @param {Object} object The object to iterate over.
 * @param {Function} iteratee The function invoked per iteration.
 * @returns {Object} Returns `object`.
 */
function baseForOwn(object, iteratee) {
  return baseFor(object, iteratee, keys);
}

/**
 * Creates a clone of the given array buffer.
 *
 * @private
 * @param {ArrayBuffer} buffer The array buffer to clone.
 * @returns {ArrayBuffer} Returns the cloned array buffer.
 */
function bufferClone(buffer) {
  return bufferSlice.call(buffer, 0);
}
if (!bufferSlice) {
  // PhantomJS has `ArrayBuffer` and `Uint8Array` but not `Float64Array`.
  bufferClone = !(ArrayBuffer && Uint8Array) ? constant(null) : function(buffer) {
    var byteLength = buffer.byteLength,
        floatLength = Float64Array ? floor(byteLength / FLOAT64_BYTES_PER_ELEMENT) : 0,
        offset = floatLength * FLOAT64_BYTES_PER_ELEMENT,
        result = new ArrayBuffer(byteLength);

    if (floatLength) {
      var view = new Float64Array(result, 0, floatLength);
      view.set(new Float64Array(buffer, 0, floatLength));
    }
    if (byteLength != offset) {
      view = new Uint8Array(result, offset);
      view.set(new Uint8Array(buffer, offset));
    }
    return result;
  };
}

/**
 * Initializes an array clone.
 *
 * @private
 * @param {Array} array The array to clone.
 * @returns {Array} Returns the initialized clone.
 */
function initCloneArray(array) {
  var length = array.length,
      result = new array.constructor(length);

  // Add array properties assigned by `RegExp#exec`.
  if (length && typeof array[0] == 'string' && hasOwnProperty.call(array, 'index')) {
    result.index = array.index;
    result.input = array.input;
  }
  return result;
}

/**
 * Initializes an object clone.
 *
 * @private
 * @param {Object} object The object to clone.
 * @returns {Object} Returns the initialized clone.
 */
function initCloneObject(object) {
  var Ctor = object.constructor;
  if (!(typeof Ctor == 'function' && Ctor instanceof Ctor)) {
    Ctor = Object;
  }
  return new Ctor;
}

/**
 * Initializes an object clone based on its `toStringTag`.
 *
 * **Note:** This function only supports cloning values with tags of
 * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`.
 *
 * @private
 * @param {Object} object The object to clone.
 * @param {string} tag The `toStringTag` of the object to clone.
 * @param {boolean} [isDeep] Specify a deep clone.
 * @returns {Object} Returns the initialized clone.
 */
function initCloneByTag(object, tag, isDeep) {
  var Ctor = object.constructor;
  switch (tag) {
    case arrayBufferTag:
      return bufferClone(object);

    case boolTag:
    case dateTag:
      return new Ctor(+object);

    case float32Tag: case float64Tag:
    case int8Tag: case int16Tag: case int32Tag:
    case uint8Tag: case uint8ClampedTag: case uint16Tag: case uint32Tag:
      var buffer = object.buffer;
      return new Ctor(isDeep ? bufferClone(buffer) : buffer, object.byteOffset, object.length);

    case numberTag:
    case stringTag:
      return new Ctor(object);

    case regexpTag:
      var result = new Ctor(object.source, reFlags.exec(object));
      result.lastIndex = object.lastIndex;
  }
  return result;
}

/**
 * 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');
}

/**
 * Creates a function that returns `value`.
 *
 * @static
 * @memberOf _
 * @category Utility
 * @param {*} value The value to return from the new function.
 * @returns {Function} Returns the new function.
 * @example
 *
 * var object = { 'user': 'fred' };
 * var getter = _.constant(object);
 *
 * getter() === object;
 * // => true
 */
function constant(value) {
  return function() {
    return value;
  };
}

module.exports = baseClone;