HORIZON PROJECT

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_PARTIAL_FLAG = 32;

/**

 * Creates a function that invokes `func` with the `this` binding of `thisArg`

 * and `partials` prepended to the arguments it receives.

 *

 * 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 doesn't set the "length"

 * property of bound functions.

 *

 * @static

 * @memberOf _

 * @since 0.1.0

 * @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

 *

 * function greet(greeting, punctuation) {

 *   return greeting + ' ' + this.user + punctuation;

 * }

 *

 * var object = { 'user': 'fred' };

 *

 * var bound = _.bind(greet, object, 'hi');

 * bound('!');

 * // => 'hi fred!'

 *

 * // Bound with placeholders.

 * var bound = _.bind(greet, object, _, '!');

 * bound('hi');

 * // => 'hi fred!'

 */

var bind = baseRest(function(func, thisArg, partials) {

  var bitmask = WRAP_BIND_FLAG;

  if (partials.length) {

    var holders = replaceHolders(partials, getHolder(bind));

    bitmask |= WRAP_PARTIAL_FLAG;

  }

  return createWrap(func, bitmask, thisArg, partials, holders);

});

// Assign default placeholders.

bind.placeholder = {};

module.exports = bind;