var baseRest = require('./_baseRest'),
      createWrap = require('./_createWrap'),
      getHolder = require('./_getHolder'),
      replaceHolders = require('./_replaceHolders');
  
  /** Used to compose bitmasks for function metadata. */
  var WRAP_PARTIAL_FLAG = 32;
  
  /**
   * Creates a function that invokes `func` with `partials` prepended to the
   * arguments it receives. 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 doesn't set the "length" property of partially
   * applied functions.
   *
   * @static
   * @memberOf _
   * @since 0.2.0
   * @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
   *
   * function greet(greeting, name) {
   *   return greeting + ' ' + name;
   * }
   *
   * var sayHelloTo = _.partial(greet, 'hello');
   * sayHelloTo('fred');
   * // => 'hello fred'
   *
   * // Partially applied with placeholders.
   * var greetFred = _.partial(greet, _, 'fred');
   * greetFred('hi');
   * // => 'hi fred'
   */
  var partial = baseRest(function(func, partials) {
    var holders = replaceHolders(partials, getHolder(partial));
    return createWrap(func, WRAP_PARTIAL_FLAG, undefined, partials, holders);
  });
  
  // Assign default placeholders.
  partial.placeholder = {};
  
  module.exports = partial;