|  | var apply = require('./_apply'), | 
|  | createCtor = require('./_createCtor'), | 
|  | root = require('./_root'); | 
|  |  | 
|  | /** Used to compose bitmasks for function metadata. */ | 
|  | var WRAP_BIND_FLAG = 1; | 
|  |  | 
|  | /** | 
|  | * Creates a function that wraps `func` to invoke it with the `this` binding | 
|  | * of `thisArg` and `partials` prepended to the arguments it receives. | 
|  | * | 
|  | * @private | 
|  | * @param {Function} func The function to wrap. | 
|  | * @param {number} bitmask The bitmask flags. See `createWrap` for more details. | 
|  | * @param {*} thisArg The `this` binding of `func`. | 
|  | * @param {Array} partials The arguments to prepend to those provided to | 
|  | *  the new function. | 
|  | * @returns {Function} Returns the new wrapped function. | 
|  | */ | 
|  | function createPartial(func, bitmask, thisArg, partials) { | 
|  | var isBind = bitmask & WRAP_BIND_FLAG, | 
|  | Ctor = createCtor(func); | 
|  |  | 
|  | function wrapper() { | 
|  | var argsIndex = -1, | 
|  | argsLength = arguments.length, | 
|  | leftIndex = -1, | 
|  | leftLength = partials.length, | 
|  | args = Array(leftLength + argsLength), | 
|  | fn = (this && this !== root && this instanceof wrapper) ? Ctor : func; | 
|  |  | 
|  | while (++leftIndex < leftLength) { | 
|  | args[leftIndex] = partials[leftIndex]; | 
|  | } | 
|  | while (argsLength--) { | 
|  | args[leftIndex++] = arguments[++argsIndex]; | 
|  | } | 
|  | return apply(fn, isBind ? thisArg : this, args); | 
|  | } | 
|  | return wrapper; | 
|  | } | 
|  |  | 
|  | module.exports = createPartial; |