add book.js

node_modules/lodash/internal/createReduce.js

@@ -0,0 +1,22 @@
+var baseCallback = require('./baseCallback'),
+    baseReduce = require('./baseReduce'),
+    isArray = require('../lang/isArray');
+
+/**
+ * Creates a function for `_.reduce` or `_.reduceRight`.
+ *
+ * @private
+ * @param {Function} arrayFunc The function to iterate over an array.
+ * @param {Function} eachFunc The function to iterate over a collection.
+ * @returns {Function} Returns the new each function.
+ */
+function createReduce(arrayFunc, eachFunc) {
+  return function(collection, iteratee, accumulator, thisArg) {
+    var initFromArray = arguments.length < 3;
+    return (typeof iteratee == 'function' && thisArg === undefined && isArray(collection))
+      ? arrayFunc(collection, iteratee, accumulator, initFromArray)
+      : baseReduce(collection, baseCallback(iteratee, thisArg, 4), accumulator, initFromArray, eachFunc);
+  };
+}
+
+module.exports = createReduce;