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- var baseRest = require('./_baseRest'),
- createWrap = require('./_createWrap'),
- getHolder = require('./_getHolder'),
- replaceHolders = require('./_replaceHolders');
- /** Used to compose bitmasks for function metadata. */
- var WRAP_BIND_FLAG = 1,
- WRAP_BIND_KEY_FLAG = 2,
- 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.
- *
- * @static
- * @memberOf _
- * @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
- *
- * var object = {
- * 'user': 'fred',
- * 'greet': function(greeting, punctuation) {
- * return greeting + ' ' + this.user + punctuation;
- * }
- * };
- *
- * var 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.
- * var bound = _.bindKey(object, 'greet', _, '!');
- * bound('hi');
- * // => 'hiya fred!'
- */
- var bindKey = baseRest(function(object, key, partials) {
- var bitmask = WRAP_BIND_FLAG | WRAP_BIND_KEY_FLAG;
- if (partials.length) {
- var holders = replaceHolders(partials, getHolder(bindKey));
- bitmask |= WRAP_PARTIAL_FLAG;
- }
- return createWrap(key, bitmask, object, partials, holders);
- });
- // Assign default placeholders.
- bindKey.placeholder = {};
- module.exports = bindKey;
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