| var createCtorWrapper = require('./createCtorWrapper'); |
| |
| /** Used to compose bitmasks for wrapper metadata. */ |
| var BIND_FLAG = 1; |
| |
| /** |
| * Creates a function that wraps `func` and invokes it with the optional `this` |
| * binding of `thisArg` and the `partials` prepended to those provided to |
| * the wrapper. |
| * |
| * @private |
| * @param {Function} func The function to partially apply arguments to. |
| * @param {number} bitmask The bitmask of flags. See `createWrapper` 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 bound function. |
| */ |
| function createPartialWrapper(func, bitmask, thisArg, partials) { |
| var isBind = bitmask & BIND_FLAG, |
| Ctor = createCtorWrapper(func); |
| |
| function wrapper() { |
| // Avoid `arguments` object use disqualifying optimizations by |
| // converting it to an array before providing it `func`. |
| var argsIndex = -1, |
| argsLength = arguments.length, |
| leftIndex = -1, |
| leftLength = partials.length, |
| args = Array(leftLength + argsLength); |
| |
| while (++leftIndex < leftLength) { |
| args[leftIndex] = partials[leftIndex]; |
| } |
| while (argsLength--) { |
| args[leftIndex++] = arguments[++argsIndex]; |
| } |
| var fn = (this && this !== global && this instanceof wrapper) ? Ctor : func; |
| return fn.apply(isBind ? thisArg : this, args); |
| } |
| return wrapper; |
| } |
| |
| module.exports = createPartialWrapper; |