--- /dev/null
+var Stack = require('./_Stack'),
+ arrayEach = require('./_arrayEach'),
+ assignValue = require('./_assignValue'),
+ baseAssign = require('./_baseAssign'),
+ baseForOwn = require('./_baseForOwn'),
+ cloneBuffer = require('./_cloneBuffer'),
+ copyArray = require('./_copyArray'),
+ copySymbols = require('./_copySymbols'),
+ getTag = require('./_getTag'),
+ initCloneArray = require('./_initCloneArray'),
+ initCloneByTag = require('./_initCloneByTag'),
+ initCloneObject = require('./_initCloneObject'),
+ isArray = require('./isArray'),
+ isBuffer = require('./isBuffer'),
+ isHostObject = require('./_isHostObject'),
+ isObject = require('./isObject');
+
+/** `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 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;
+
+/**
+ * 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);
+}
+
+module.exports = baseClone;