lodash/lodash.defaultsdeep/index.js

/**
 * lodash 4.1.1 (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o ./`
 * Copyright 2012-2016 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2016 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <https://lodash.com/license>
 */
var Stack = require('lodash._stack'),
    arrayEach = require('lodash._arrayeach'),
    baseFor = require('lodash._basefor'),
    isBuffer = require('lodash.isbuffer'),
    isPlainObject = require('lodash.isplainobject'),
    keys = require('lodash.keys'),
    keysIn = require('lodash.keysin'),
    mergeWith = require('lodash.mergewith'),
    rest = require('lodash.rest'),
    root = require('lodash._root');

/** Used as references for various `Number` constants. */
var MAX_SAFE_INTEGER = 9007199254740991;

/** `Object#toString` result references. */
var argsTag = '[object Arguments]',
    arrayTag = '[object Array]',
    boolTag = '[object Boolean]',
    dateTag = '[object Date]',
    errorTag = '[object Error]',
    funcTag = '[object Function]',
    genTag = '[object GeneratorFunction]',
    mapTag = '[object Map]',
    numberTag = '[object Number]',
    objectTag = '[object Object]',
    regexpTag = '[object RegExp]',
    setTag = '[object Set]',
    stringTag = '[object String]',
    symbolTag = '[object Symbol]',
    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` [syntax characters](http://ecma-international.org/ecma-262/6.0/#sec-patterns). */
var reRegExpChar = /[\\^$.*+?()[\]{}|]/g;

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

/** Used to detect host constructors (Safari > 5). */
var reIsHostCtor = /^\[object .+?Constructor\]$/;

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

/** 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[mapTag] = cloneableTags[numberTag] =
cloneableTags[objectTag] = cloneableTags[regexpTag] =
cloneableTags[setTag] = cloneableTags[stringTag] =
cloneableTags[symbolTag] = cloneableTags[uint8Tag] =
cloneableTags[uint8ClampedTag] = cloneableTags[uint16Tag] =
cloneableTags[uint32Tag] = true;
cloneableTags[errorTag] = cloneableTags[funcTag] =
cloneableTags[weakMapTag] = false;

/**
 * Adds the key-value `pair` to `map`.
 *
 * @private
 * @param {Object} map The map to modify.
 * @param {Array} pair The key-value pair to add.
 * @returns {Object} Returns `map`.
 */
function addMapEntry(map, pair) {
  map.set(pair[0], pair[1]);
  return map;
}

/**
 * Adds `value` to `set`.
 *
 * @private
 * @param {Object} set The set to modify.
 * @param {*} value The value to add.
 * @returns {Object} Returns `set`.
 */
function addSetEntry(set, value) {
  set.add(value);
  return set;
}

/**
 * A faster alternative to `Function#apply`, this function invokes `func`
 * with the `this` binding of `thisArg` and the arguments of `args`.
 *
 * @private
 * @param {Function} func The function to invoke.
 * @param {*} thisArg The `this` binding of `func`.
 * @param {...*} args The arguments to invoke `func` with.
 * @returns {*} Returns the result of `func`.
 */
function apply(func, thisArg, args) {
  var length = args.length;
  switch (length) {
    case 0: return func.call(thisArg);
    case 1: return func.call(thisArg, args[0]);
    case 2: return func.call(thisArg, args[0], args[1]);
    case 3: return func.call(thisArg, args[0], args[1], args[2]);
  }
  return func.apply(thisArg, args);
}

/**
 * A specialized version of `_.reduce` for arrays without support for
 * iteratee shorthands.
 *
 * @private
 * @param {Array} array The array to iterate over.
 * @param {Function} iteratee The function invoked per iteration.
 * @param {*} [accumulator] The initial value.
 * @param {boolean} [initAccum] Specify using the first element of `array` as the initial value.
 * @returns {*} Returns the accumulated value.
 */
function arrayReduce(array, iteratee, accumulator, initAccum) {
  var index = -1,
      length = array.length;

  if (initAccum && length) {
    accumulator = array[++index];
  }
  while (++index < length) {
    accumulator = iteratee(accumulator, array[index], index, array);
  }
  return accumulator;
}

/**
 * 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;
}

/**
 * Converts `map` to an array.
 *
 * @private
 * @param {Object} map The map to convert.
 * @returns {Array} Returns the converted array.
 */
function mapToArray(map) {
  var index = -1,
      result = Array(map.size);

  map.forEach(function(value, key) {
    result[++index] = [key, value];
  });
  return result;
}

/**
 * Converts `set` to an array.
 *
 * @private
 * @param {Object} set The set to convert.
 * @returns {Array} Returns the converted array.
 */
function setToArray(set) {
  var index = -1,
      result = Array(set.size);

  set.forEach(function(value) {
    result[++index] = value;
  });
  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 value references. */
var Symbol = root.Symbol,
    Uint8Array = root.Uint8Array,
    getOwnPropertySymbols = Object.getOwnPropertySymbols,
    propertyIsEnumerable = objectProto.propertyIsEnumerable;

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

/** Used to detect maps, sets, and weakmaps. */
var mapCtorString = Map ? funcToString.call(Map) : '',
    setCtorString = Set ? funcToString.call(Set) : '',
    weakMapCtorString = WeakMap ? funcToString.call(WeakMap) : '';

/** Used to convert symbols to primitives and strings. */
var symbolProto = Symbol ? Symbol.prototype : undefined,
    symbolValueOf = Symbol ? symbolProto.valueOf : undefined;

/**
 * This function is like `assignValue` except that it doesn't assign `undefined` values.
 *
 * @private
 * @param {Object} object The object to modify.
 * @param {string} key The key of the property to assign.
 * @param {*} value The value to assign.
 */
function assignMergeValue(object, key, value) {
  if ((value !== undefined && !eq(object[key], value)) ||
      (typeof key == 'number' && value === undefined && !(key in object))) {
    object[key] = value;
  }
}

/**
 * Assigns `value` to `key` of `object` if the existing value is not equivalent
 * using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
 * for equality comparisons.
 *
 * @private
 * @param {Object} object The object to modify.
 * @param {string} key The key of the property to assign.
 * @param {*} value The value to assign.
 */
function assignValue(object, key, value) {
  var objValue = object[key];
  if ((!eq(objValue, value) ||
        (eq(objValue, objectProto[key]) && !hasOwnProperty.call(object, key))) ||
      (value === undefined && !(key in object))) {
    object[key] = value;
  }
}

/**
 * The base implementation of `_.assign` without support for multiple sources
 * or `customizer` functions.
 *
 * @private
 * @param {Object} object The destination object.
 * @param {Object} source The source object.
 * @returns {Object} Returns `object`.
 */
function baseAssign(object, source) {
  return object && copyObject(source, keys(source), object);
}

/**
 * The base implementation of `_.clone` and `_.cloneDeep` which tracks
 * traversed objects.
 *
 * @private
 * @param {*} value The value to clone.
 * @param {boolean} [isDeep] Specify a deep clone.
 * @param {Function} [customizer] The function to customize cloning.
 * @param {string} [key] The key of `value`.
 * @param {Object} [object] The parent object of `value`.
 * @param {Object} [stack] Tracks traversed objects and their clone counterparts.
 * @returns {*} Returns the cloned value.
 */
function baseClone(value, isDeep, customizer, key, object, stack) {
  var result;
  if (customizer) {
    result = object ? customizer(value, key, object, stack) : customizer(value);
  }
  if (result !== undefined) {
    return result;
  }
  if (!isObject(value)) {
    return value;
  }
  var isArr = isArray(value);
  if (isArr) {
    result = initCloneArray(value);
    if (!isDeep) {
      return copyArray(value, result);
    }
  } else {
    var tag = getTag(value),
        isFunc = tag == funcTag || tag == genTag;

    if (isBuffer(value)) {
      return cloneBuffer(value, isDeep);
    }
    if (tag == objectTag || tag == argsTag || (isFunc && !object)) {
      if (isHostObject(value)) {
        return object ? value : {};
      }
      result = initCloneObject(isFunc ? {} : value);
      if (!isDeep) {
        return copySymbols(value, baseAssign(result, value));
      }
    } else {
      return cloneableTags[tag]
        ? initCloneByTag(value, tag, isDeep)
        : (object ? value : {});
    }
  }
  // Check for circular references and return its corresponding clone.
  stack || (stack = new Stack);
  var stacked = stack.get(value);
  if (stacked) {
    return stacked;
  }
  stack.set(value, result);

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

/**
 * The base implementation of `_.create` without support for assigning
 * properties to the created object.
 *
 * @private
 * @param {Object} prototype The object to inherit from.
 * @returns {Object} Returns the new object.
 */
var baseCreate = (function() {
  function object() {}
  return function(prototype) {
    if (isObject(prototype)) {
      object.prototype = prototype;
      var result = new object;
      object.prototype = undefined;
    }
    return result || {};
  };
}());

/**
 * The base implementation of `_.forOwn` without support for iteratee shorthands.
 *
 * @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 object && baseFor(object, iteratee, keys);
}

/**
 * The base implementation of `_.merge` without support for multiple sources.
 *
 * @private
 * @param {Object} object The destination object.
 * @param {Object} source The source object.
 * @param {number} srcIndex The index of `source`.
 * @param {Function} [customizer] The function to customize merged values.
 * @param {Object} [stack] Tracks traversed source values and their merged counterparts.
 */
function baseMerge(object, source, srcIndex, customizer, stack) {
  if (object === source) {
    return;
  }
  var props = (isArray(source) || isTypedArray(source)) ? undefined : keysIn(source);
  arrayEach(props || source, function(srcValue, key) {
    if (props) {
      key = srcValue;
      srcValue = source[key];
    }
    if (isObject(srcValue)) {
      stack || (stack = new Stack);
      baseMergeDeep(object, source, key, srcIndex, baseMerge, customizer, stack);
    }
    else {
      var newValue = customizer ? customizer(object[key], srcValue, (key + ''), object, source, stack) : undefined;
      if (newValue === undefined) {
        newValue = srcValue;
      }
      assignMergeValue(object, key, newValue);
    }
  });
}

/**
 * A specialized version of `baseMerge` for arrays and objects which performs
 * deep merges and tracks traversed objects enabling objects with circular
 * references to be merged.
 *
 * @private
 * @param {Object} object The destination object.
 * @param {Object} source The source object.
 * @param {string} key The key of the value to merge.
 * @param {number} srcIndex The index of `source`.
 * @param {Function} mergeFunc The function to merge values.
 * @param {Function} [customizer] The function to customize assigned values.
 * @param {Object} [stack] Tracks traversed source values and their merged counterparts.
 */
function baseMergeDeep(object, source, key, srcIndex, mergeFunc, customizer, stack) {
  var objValue = object[key],
      srcValue = source[key],
      stacked = stack.get(srcValue);

  if (stacked) {
    assignMergeValue(object, key, stacked);
    return;
  }
  var newValue = customizer ? customizer(objValue, srcValue, (key + ''), object, source, stack) : undefined,
      isCommon = newValue === undefined;

  if (isCommon) {
    newValue = srcValue;
    if (isArray(srcValue) || isTypedArray(srcValue)) {
      if (isArray(objValue)) {
        newValue = srcIndex ? copyArray(objValue) : objValue;
      }
      else if (isArrayLikeObject(objValue)) {
        newValue = copyArray(objValue);
      }
      else {
        isCommon = false;
        newValue = baseClone(srcValue);
      }
    }
    else if (isPlainObject(srcValue) || isArguments(srcValue)) {
      if (isArguments(objValue)) {
        newValue = toPlainObject(objValue);
      }
      else if (!isObject(objValue) || (srcIndex && isFunction(objValue))) {
        isCommon = false;
        newValue = baseClone(srcValue);
      }
      else {
        newValue = srcIndex ? baseClone(objValue) : objValue;
      }
    }
    else {
      isCommon = false;
    }
  }
  stack.set(srcValue, newValue);

  if (isCommon) {
    // Recursively merge objects and arrays (susceptible to call stack limits).
    mergeFunc(newValue, srcValue, srcIndex, customizer, stack);
  }
  assignMergeValue(object, key, newValue);
}

/**
 * The base implementation of `_.property` without support for deep paths.
 *
 * @private
 * @param {string} key The key of the property to get.
 * @returns {Function} Returns the new function.
 */
function baseProperty(key) {
  return function(object) {
    return object == null ? undefined : object[key];
  };
}

/**
 * Creates a clone of  `buffer`.
 *
 * @private
 * @param {Buffer} buffer The buffer to clone.
 * @param {boolean} [isDeep] Specify a deep clone.
 * @returns {Buffer} Returns the cloned buffer.
 */
function cloneBuffer(buffer, isDeep) {
  if (isDeep) {
    return buffer.slice();
  }
  var Ctor = buffer.constructor,
      result = new Ctor(buffer.length);

  buffer.copy(result);
  return result;
}

/**
 * Creates a clone of `arrayBuffer`.
 *
 * @private
 * @param {ArrayBuffer} arrayBuffer The array buffer to clone.
 * @returns {ArrayBuffer} Returns the cloned array buffer.
 */
function cloneArrayBuffer(arrayBuffer) {
  var Ctor = arrayBuffer.constructor,
      result = new Ctor(arrayBuffer.byteLength),
      view = new Uint8Array(result);

  view.set(new Uint8Array(arrayBuffer));
  return result;
}

/**
 * Creates a clone of `map`.
 *
 * @private
 * @param {Object} map The map to clone.
 * @returns {Object} Returns the cloned map.
 */
function cloneMap(map) {
  var Ctor = map.constructor;
  return arrayReduce(mapToArray(map), addMapEntry, new Ctor);
}

/**
 * Creates a clone of `regexp`.
 *
 * @private
 * @param {Object} regexp The regexp to clone.
 * @returns {Object} Returns the cloned regexp.
 */
function cloneRegExp(regexp) {
  var Ctor = regexp.constructor,
      result = new Ctor(regexp.source, reFlags.exec(regexp));

  result.lastIndex = regexp.lastIndex;
  return result;
}

/**
 * Creates a clone of `set`.
 *
 * @private
 * @param {Object} set The set to clone.
 * @returns {Object} Returns the cloned set.
 */
function cloneSet(set) {
  var Ctor = set.constructor;
  return arrayReduce(setToArray(set), addSetEntry, new Ctor);
}

/**
 * Creates a clone of the `symbol` object.
 *
 * @private
 * @param {Object} symbol The symbol object to clone.
 * @returns {Object} Returns the cloned symbol object.
 */
function cloneSymbol(symbol) {
  return Symbol ? Object(symbolValueOf.call(symbol)) : {};
}

/**
 * Creates a clone of `typedArray`.
 *
 * @private
 * @param {Object} typedArray The typed array to clone.
 * @param {boolean} [isDeep] Specify a deep clone.
 * @returns {Object} Returns the cloned typed array.
 */
function cloneTypedArray(typedArray, isDeep) {
  var buffer = typedArray.buffer,
      Ctor = typedArray.constructor;

  return new Ctor(isDeep ? cloneArrayBuffer(buffer) : buffer, typedArray.byteOffset, typedArray.length);
}

/**
 * Copies the values of `source` to `array`.
 *
 * @private
 * @param {Array} source The array to copy values from.
 * @param {Array} [array=[]] The array to copy values to.
 * @returns {Array} Returns `array`.
 */
function copyArray(source, array) {
  var index = -1,
      length = source.length;

  array || (array = Array(length));
  while (++index < length) {
    array[index] = source[index];
  }
  return array;
}

/**
 * Copies properties of `source` to `object`.
 *
 * @private
 * @param {Object} source The object to copy properties from.
 * @param {Array} props The property names to copy.
 * @param {Object} [object={}] The object to copy properties to.
 * @returns {Object} Returns `object`.
 */
function copyObject(source, props, object) {
  return copyObjectWith(source, props, object);
}

/**
 * This function is like `copyObject` except that it accepts a function to
 * customize copied values.
 *
 * @private
 * @param {Object} source The object to copy properties from.
 * @param {Array} props The property names to copy.
 * @param {Object} [object={}] The object to copy properties to.
 * @param {Function} [customizer] The function to customize copied values.
 * @returns {Object} Returns `object`.
 */
function copyObjectWith(source, props, object, customizer) {
  object || (object = {});

  var index = -1,
      length = props.length;

  while (++index < length) {
    var key = props[index],
        newValue = customizer ? customizer(object[key], source[key], key, object, source) : source[key];

    assignValue(object, key, newValue);
  }
  return object;
}

/**
 * Copies own symbol properties of `source` to `object`.
 *
 * @private
 * @param {Object} source The object to copy symbols from.
 * @param {Object} [object={}] The object to copy symbols to.
 * @returns {Object} Returns `object`.
 */
function copySymbols(source, object) {
  return copyObject(source, getSymbols(source), object);
}

/**
 * Gets the "length" property value of `object`.
 *
 * **Note:** This function is used to avoid a [JIT bug](https://bugs.webkit.org/show_bug.cgi?id=142792)
 * that affects Safari on at least iOS 8.1-8.3 ARM64.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {*} Returns the "length" value.
 */
var getLength = baseProperty('length');

/**
 * 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;
}

/**
 * Creates an array of the own symbol properties of `object`.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {Array} Returns the array of symbols.
 */
var getSymbols = getOwnPropertySymbols || function() {
  return [];
};

/**
 * Gets the `toStringTag` of `value`.
 *
 * @private
 * @param {*} value The value to query.
 * @returns {string} Returns the `toStringTag`.
 */
function getTag(value) {
  return objectToString.call(value);
}

// Fallback for IE 11 providing `toStringTag` values for maps, sets, and weakmaps.
if ((Map && getTag(new Map) != mapTag) ||
    (Set && getTag(new Set) != setTag) ||
    (WeakMap && getTag(new WeakMap) != weakMapTag)) {
  getTag = function(value) {
    var result = objectToString.call(value),
        Ctor = result == objectTag ? value.constructor : null,
        ctorString = typeof Ctor == 'function' ? funcToString.call(Ctor) : '';

    if (ctorString) {
      switch (ctorString) {
        case mapCtorString: return mapTag;
        case setCtorString: return setTag;
        case weakMapCtorString: return weakMapTag;
      }
    }
    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 = array.constructor(length);

  // Add 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) {
  if (isPrototype(object)) {
    return {};
  }
  var Ctor = object.constructor;
  return baseCreate(isFunction(Ctor) ? Ctor.prototype : undefined);
}

/**
 * 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 cloneArrayBuffer(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:
      return cloneTypedArray(object, isDeep);

    case mapTag:
      return cloneMap(object);

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

    case regexpTag:
      return cloneRegExp(object);

    case setTag:
      return cloneSet(object);

    case symbolTag:
      return cloneSymbol(object);
  }
}

/**
 * Checks if `value` is likely a prototype object.
 *
 * @private
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a prototype, else `false`.
 */
function isPrototype(value) {
  var Ctor = value && value.constructor,
      proto = (typeof Ctor == 'function' && Ctor.prototype) || objectProto;

  return value === proto;
}

/**
 * Used by `_.defaultsDeep` to customize its `_.merge` use.
 *
 * @private
 * @param {*} objValue The destination value.
 * @param {*} srcValue The source value.
 * @param {string} key The key of the property to merge.
 * @param {Object} object The parent object of `objValue`.
 * @param {Object} source The parent object of `srcValue`.
 * @param {Object} [stack] Tracks traversed source values and their merged counterparts.
 * @returns {*} Returns the value to assign.
 */
function mergeDefaults(objValue, srcValue, key, object, source, stack) {
  if (isObject(objValue) && isObject(srcValue)) {
    stack.set(srcValue, objValue);
    baseMerge(objValue, srcValue, undefined, mergeDefaults, stack);
  }
  return objValue;
}

/**
 * Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
 * comparison between two values to determine if they are equivalent.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to compare.
 * @param {*} other The other value to compare.
 * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
 * @example
 *
 * var object = { 'user': 'fred' };
 * var other = { 'user': 'fred' };
 *
 * _.eq(object, object);
 * // => true
 *
 * _.eq(object, other);
 * // => false
 *
 * _.eq('a', 'a');
 * // => true
 *
 * _.eq('a', Object('a'));
 * // => false
 *
 * _.eq(NaN, NaN);
 * // => true
 */
function eq(value, other) {
  return value === other || (value !== value && other !== other);
}

/**
 * Checks if `value` is likely an `arguments` object.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
 * @example
 *
 * _.isArguments(function() { return arguments; }());
 * // => true
 *
 * _.isArguments([1, 2, 3]);
 * // => false
 */
function isArguments(value) {
  // Safari 8.1 incorrectly makes `arguments.callee` enumerable in strict mode.
  return isArrayLikeObject(value) && hasOwnProperty.call(value, 'callee') &&
    (!propertyIsEnumerable.call(value, 'callee') || objectToString.call(value) == argsTag);
}

/**
 * Checks if `value` is classified as an `Array` object.
 *
 * @static
 * @memberOf _
 * @type Function
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
 * @example
 *
 * _.isArray([1, 2, 3]);
 * // => true
 *
 * _.isArray(document.body.children);
 * // => false
 *
 * _.isArray('abc');
 * // => false
 *
 * _.isArray(_.noop);
 * // => false
 */
var isArray = Array.isArray;

/**
 * Checks if `value` is array-like. A value is considered array-like if it's
 * not a function and has a `value.length` that's an integer greater than or
 * equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
 *
 * @static
 * @memberOf _
 * @type Function
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is array-like, else `false`.
 * @example
 *
 * _.isArrayLike([1, 2, 3]);
 * // => true
 *
 * _.isArrayLike(document.body.children);
 * // => true
 *
 * _.isArrayLike('abc');
 * // => true
 *
 * _.isArrayLike(_.noop);
 * // => false
 */
function isArrayLike(value) {
  return value != null &&
    !(typeof value == 'function' && isFunction(value)) && isLength(getLength(value));
}

/**
 * This method is like `_.isArrayLike` except that it also checks if `value`
 * is an object.
 *
 * @static
 * @memberOf _
 * @type Function
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an array-like object, else `false`.
 * @example
 *
 * _.isArrayLikeObject([1, 2, 3]);
 * // => true
 *
 * _.isArrayLikeObject(document.body.children);
 * // => true
 *
 * _.isArrayLikeObject('abc');
 * // => false
 *
 * _.isArrayLikeObject(_.noop);
 * // => false
 */
function isArrayLikeObject(value) {
  return isObjectLike(value) && isArrayLike(value);
}

/**
 * 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 Safari 8 which returns 'object' for typed array 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 a valid array-like length.
 *
 * **Note:** This function is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength).
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a valid length, else `false`.
 * @example
 *
 * _.isLength(3);
 * // => true
 *
 * _.isLength(Number.MIN_VALUE);
 * // => false
 *
 * _.isLength(Infinity);
 * // => false
 *
 * _.isLength('3');
 * // => false
 */
function isLength(value) {
  return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
}

/**
 * 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(_.noop);
 * // => true
 *
 * _.isObject(null);
 * // => false
 */
function isObject(value) {
  var type = typeof value;
  return !!value && (type == 'object' || type == 'function');
}

/**
 * Checks if `value` is object-like. A value is object-like if it's not `null`
 * and has a `typeof` result of "object".
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
 * @example
 *
 * _.isObjectLike({});
 * // => true
 *
 * _.isObjectLike([1, 2, 3]);
 * // => true
 *
 * _.isObjectLike(_.noop);
 * // => false
 *
 * _.isObjectLike(null);
 * // => false
 */
function isObjectLike(value) {
  return !!value && typeof value == 'object';
}

/**
 * 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(funcToString.call(value));
  }
  return isObjectLike(value) &&
    (isHostObject(value) ? reIsNative : reIsHostCtor).test(value);
}

/**
 * Checks if `value` is classified as a typed array.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
 * @example
 *
 * _.isTypedArray(new Uint8Array);
 * // => true
 *
 * _.isTypedArray([]);
 * // => false
 */
function isTypedArray(value) {
  return isObjectLike(value) && isLength(value.length) && !!typedArrayTags[objectToString.call(value)];
}

/**
 * Converts `value` to a plain object flattening inherited enumerable
 * properties of `value` to own properties of the plain object.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to convert.
 * @returns {Object} Returns the converted plain object.
 * @example
 *
 * function Foo() {
 *   this.b = 2;
 * }
 *
 * Foo.prototype.c = 3;
 *
 * _.assign({ 'a': 1 }, new Foo);
 * // => { 'a': 1, 'b': 2 }
 *
 * _.assign({ 'a': 1 }, _.toPlainObject(new Foo));
 * // => { 'a': 1, 'b': 2, 'c': 3 }
 */
function toPlainObject(value) {
  return copyObject(value, keysIn(value));
}

/**
 * This method is like `_.defaults` except that it recursively assigns
 * default properties.
 *
 * **Note:** This method mutates `object`.
 *
 * @static
 * @memberOf _
 * @category Object
 * @param {Object} object The destination object.
 * @param {...Object} [sources] The source objects.
 * @returns {Object} Returns `object`.
 * @example
 *
 * _.defaultsDeep({ 'user': { 'name': 'barney' } }, { 'user': { 'name': 'fred', 'age': 36 } });
 * // => { 'user': { 'name': 'barney', 'age': 36 } }
 *
 */
var defaultsDeep = rest(function(args) {
  args.push(undefined, mergeDefaults);
  return apply(mergeWith, undefined, args);
});

module.exports = defaultsDeep;