Bump to v4.1.0.

_createFlow.js

@@ -0,0 +1,79 @@
+var LodashWrapper = require('./_LodashWrapper'),
+    baseFlatten = require('./_baseFlatten'),
+    getData = require('./_getData'),
+    getFuncName = require('./_getFuncName'),
+    isArray = require('./isArray'),
+    isLaziable = require('./_isLaziable'),
+    rest = require('./rest');
+
+/** Used to compose bitmasks for wrapper metadata. */
+var CURRY_FLAG = 8,
+    PARTIAL_FLAG = 32,
+    ARY_FLAG = 128,
+    REARG_FLAG = 256;
+
+/** Used as the size to enable large array optimizations. */
+var LARGE_ARRAY_SIZE = 200;
+
+/** Used as the `TypeError` message for "Functions" methods. */
+var FUNC_ERROR_TEXT = 'Expected a function';
+
+/**
+ * Creates a `_.flow` or `_.flowRight` function.
+ *
+ * @private
+ * @param {boolean} [fromRight] Specify iterating from right to left.
+ * @returns {Function} Returns the new flow function.
+ */
+function createFlow(fromRight) {
+  return rest(function(funcs) {
+    funcs = baseFlatten(funcs);
+
+    var length = funcs.length,
+        index = length,
+        prereq = LodashWrapper.prototype.thru;
+
+    if (fromRight) {
+      funcs.reverse();
+    }
+    while (index--) {
+      var func = funcs[index];
+      if (typeof func != 'function') {
+        throw new TypeError(FUNC_ERROR_TEXT);
+      }
+      if (prereq && !wrapper && getFuncName(func) == 'wrapper') {
+        var wrapper = new LodashWrapper([], true);
+      }
+    }
+    index = wrapper ? index : length;
+    while (++index < length) {
+      func = funcs[index];
+
+      var funcName = getFuncName(func),
+          data = funcName == 'wrapper' ? getData(func) : undefined;
+
+      if (data && isLaziable(data[0]) && data[1] == (ARY_FLAG | CURRY_FLAG | PARTIAL_FLAG | REARG_FLAG) && !data[4].length && data[9] == 1) {
+        wrapper = wrapper[getFuncName(data[0])].apply(wrapper, data[3]);
+      } else {
+        wrapper = (func.length == 1 && isLaziable(func)) ? wrapper[funcName]() : wrapper.thru(func);
+      }
+    }
+    return function() {
+      var args = arguments,
+          value = args[0];
+
+      if (wrapper && args.length == 1 && isArray(value) && value.length >= LARGE_ARRAY_SIZE) {
+        return wrapper.plant(value).value();
+      }
+      var index = 0,
+          result = length ? funcs[index].apply(this, args) : value;
+
+      while (++index < length) {
+        result = funcs[index].call(this, result);
+      }
+      return result;
+    };
+  });
+}
+
+module.exports = createFlow;