/**
 * lodash 3.1.1 (Custom Build) <https://lodash.com/>
 * Build: `lodash modern modularize exports="npm" -o ./`
 * Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <https://lodash.com/license>
 */
var createWrapper = require('lodash._createwrapper'),
    replaceHolders = require('lodash._replaceholders'),
    restParam = require('lodash.restparam');

/** Used to compose bitmasks for wrapper metadata. */
var PARTIAL_FLAG = 32;

/**
 * Creates a `_.partial` or `_.partialRight` function.
 *
 * @private
 * @param {boolean} flag The partial bit flag.
 * @returns {Function} Returns the new partial function.
 */
function createPartial(flag) {
  var partialFunc = restParam(function(func, partials) {
    var holders = replaceHolders(partials, partialFunc.placeholder);
    return createWrapper(func, flag, undefined, partials, holders);
  });
  return partialFunc;
}

/**
 * Creates a function that invokes `func` with `partial` arguments prepended
 * to those provided to the new function. This method is like `_.bind` except
 * it does **not** alter the `this` binding.
 *
 * The `_.partial.placeholder` value, which defaults to `_` in monolithic
 * builds, may be used as a placeholder for partially applied arguments.
 *
 * **Note:** This method does not set the "length" property of partially
 * applied functions.
 *
 * @static
 * @memberOf _
 * @category Function
 * @param {Function} func The function to partially apply arguments to.
 * @param {...*} [partials] The arguments to be partially applied.
 * @returns {Function} Returns the new partially applied function.
 * @example
 *
 * var greet = function(greeting, name) {
 *   return greeting + ' ' + name;
 * };
 *
 * var sayHelloTo = _.partial(greet, 'hello');
 * sayHelloTo('fred');
 * // => 'hello fred'
 *
 * // using placeholders
 * var greetFred = _.partial(greet, _, 'fred');
 * greetFred('hi');
 * // => 'hi fred'
 */
var partial = createPartial(PARTIAL_FLAG);

// Assign default placeholders.
partial.placeholder = {};

module.exports = partial;