| import createWrap from './.internal/createWrap.js' | |
| import getHolder from './.internal/getHolder.js' | |
| import replaceHolders from './.internal/replaceHolders.js' | |
| /** Used to compose bitmasks for function metadata. */ | |
| const WRAP_BIND_FLAG = 1 | |
| const WRAP_BIND_KEY_FLAG = 2 | |
| const WRAP_PARTIAL_FLAG = 32 | |
| /** | |
| * Creates a function that invokes the method at `object[key]` with `partials` | |
| * prepended to the arguments it receives. | |
| * | |
| * This method differs from `bind` by allowing bound functions to reference | |
| * methods that may be redefined or don't yet exist. See | |
| * [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) | |
| * for more details. | |
| * | |
| * The `bindKey.placeholder` value, which defaults to `_` in monolithic | |
| * builds, may be used as a placeholder for partially applied arguments. | |
| * | |
| * @since 0.10.0 | |
| * @category Function | |
| * @param {Object} object The object to invoke the method on. | |
| * @param {string} key The key of the method. | |
| * @param {...*} [partials] The arguments to be partially applied. | |
| * @returns {Function} Returns the new bound function. | |
| * @example | |
| * | |
| * const object = { | |
| * 'user': 'fred', | |
| * 'greet': function(greeting, punctuation) { | |
| * return greeting + ' ' + this.user + punctuation | |
| * } | |
| * } | |
| * | |
| * const bound = bindKey(object, 'greet', 'hi') | |
| * bound('!') | |
| * // => 'hi fred!' | |
| * | |
| * object.greet = function(greeting, punctuation) { | |
| * return greeting + 'ya ' + this.user + punctuation | |
| * } | |
| * | |
| * bound('!') | |
| * // => 'hiya fred!' | |
| * | |
| * // Bound with placeholders. | |
| * const bound = bindKey(object, 'greet', _, '!') | |
| * bound('hi') | |
| * // => 'hiya fred!' | |
| */ | |
| function bindKey(object, key, ...partials) { | |
| let holders | |
| let bitmask = WRAP_BIND_FLAG | WRAP_BIND_KEY_FLAG | |
| if (partials.length) { | |
| holders = replaceHolders(partials, getHolder(bindKey)) | |
| bitmask |= WRAP_PARTIAL_FLAG | |
| } | |
| return createWrap(key, bitmask, object, partials, holders) | |
| } | |
| // Assign default placeholders. | |
| bindKey.placeholder = {} | |
| export default bindKey |
