| var createWrapper = require('../internal/createWrapper'), |
| replaceHolders = require('../internal/replaceHolders'), |
| restParam = require('./restParam'); |
| |
| /** Used to compose bitmasks for wrapper metadata. */ |
| var BIND_FLAG = 1, |
| PARTIAL_FLAG = 32; |
| |
| /** |
| * Creates a function that invokes `func` with the `this` binding of `thisArg` |
| * and prepends any additional `_.bind` arguments to those provided to the |
| * bound function. |
| * |
| * The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, |
| * may be used as a placeholder for partially applied arguments. |
| * |
| * **Note:** Unlike native `Function#bind` this method does not set the "length" |
| * property of bound functions. |
| * |
| * @static |
| * @memberOf _ |
| * @category Function |
| * @param {Function} func The function to bind. |
| * @param {*} thisArg The `this` binding of `func`. |
| * @param {...*} [partials] The arguments to be partially applied. |
| * @returns {Function} Returns the new bound function. |
| * @example |
| * |
| * var greet = function(greeting, punctuation) { |
| * return greeting + ' ' + this.user + punctuation; |
| * }; |
| * |
| * var object = { 'user': 'fred' }; |
| * |
| * var bound = _.bind(greet, object, 'hi'); |
| * bound('!'); |
| * // => 'hi fred!' |
| * |
| * // using placeholders |
| * var bound = _.bind(greet, object, _, '!'); |
| * bound('hi'); |
| * // => 'hi fred!' |
| */ |
| var bind = restParam(function(func, thisArg, partials) { |
| var bitmask = BIND_FLAG; |
| if (partials.length) { |
| var holders = replaceHolders(partials, bind.placeholder); |
| bitmask |= PARTIAL_FLAG; |
| } |
| return createWrapper(func, bitmask, thisArg, partials, holders); |
| }); |
| |
| // Assign default placeholders. |
| bind.placeholder = {}; |
| |
| module.exports = bind; |