--- /dev/null
+var Symbol = require('./Symbol'),
+ Uint8Array = require('./Uint8Array'),
+ mapToArray = require('./mapToArray'),
+ setToArray = require('./setToArray');
+
+/** Used to compose bitmasks for comparison styles. */
+var UNORDERED_COMPARE_FLAG = 1,
+ PARTIAL_COMPARE_FLAG = 2;
+
+/** `Object#toString` result references. */
+var boolTag = '[object Boolean]',
+ dateTag = '[object Date]',
+ errorTag = '[object Error]',
+ mapTag = '[object Map]',
+ numberTag = '[object Number]',
+ regexpTag = '[object RegExp]',
+ setTag = '[object Set]',
+ stringTag = '[object String]',
+ symbolTag = '[object Symbol]';
+
+var arrayBufferTag = '[object ArrayBuffer]';
+
+/** Used to convert symbols to primitives and strings. */
+var symbolProto = Symbol ? Symbol.prototype : undefined,
+ symbolValueOf = Symbol ? symbolProto.valueOf : undefined;
+
+/**
+ * A specialized version of `baseIsEqualDeep` for comparing objects of
+ * the same `toStringTag`.
+ *
+ * **Note:** This function only supports comparing values with tags of
+ * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`.
+ *
+ * @private
+ * @param {Object} object The object to compare.
+ * @param {Object} other The other object to compare.
+ * @param {string} tag The `toStringTag` of the objects to compare.
+ * @param {Function} equalFunc The function to determine equivalents of values.
+ * @param {Function} [customizer] The function to customize comparisons.
+ * @param {number} [bitmask] The bitmask of comparison flags. See `baseIsEqual` for more details.
+ * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
+ */
+function equalByTag(object, other, tag, equalFunc, customizer, bitmask) {
+ switch (tag) {
+ case arrayBufferTag:
+ if ((object.byteLength != other.byteLength) ||
+ !equalFunc(new Uint8Array(object), new Uint8Array(other))) {
+ return false;
+ }
+ return true;
+
+ case boolTag:
+ case dateTag:
+ // Coerce dates and booleans to numbers, dates to milliseconds and booleans
+ // to `1` or `0` treating invalid dates coerced to `NaN` as not equal.
+ return +object == +other;
+
+ case errorTag:
+ return object.name == other.name && object.message == other.message;
+
+ case numberTag:
+ // Treat `NaN` vs. `NaN` as equal.
+ return (object != +object) ? other != +other : object == +other;
+
+ case regexpTag:
+ case stringTag:
+ // Coerce regexes to strings and treat strings primitives and string
+ // objects as equal. See https://es5.github.io/#x15.10.6.4 for more details.
+ return object == (other + '');
+
+ case mapTag:
+ var convert = mapToArray;
+
+ case setTag:
+ var isPartial = bitmask & PARTIAL_COMPARE_FLAG;
+ convert || (convert = setToArray);
+
+ // Recursively compare objects (susceptible to call stack limits).
+ return (isPartial || object.size == other.size) &&
+ equalFunc(convert(object), convert(other), customizer, bitmask | UNORDERED_COMPARE_FLAG);
+
+ case symbolTag:
+ return !!Symbol && (symbolValueOf.call(object) == symbolValueOf.call(other));
+ }
+ return false;
+}
+
+module.exports = equalByTag;