# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.


/**
 * lang.js - Some missing JavaScript language features
 */

/**
 * Partially applies a function to a particular "this object" and zero or
 * more arguments. The result is a new function with some arguments of the first
 * function pre-filled and the value of |this| "pre-specified".
 *
 * Remaining arguments specified at call-time are appended to the pre-
 * specified ones.
 *
 * Usage:
 * var barMethBound = BindToObject(myFunction, myObj, "arg1", "arg2");
 * barMethBound("arg3", "arg4");
 *
 * @param fn {string} Reference to the function to be bound
 *
 * @param self {object} Specifies the object which |this| should point to
 * when the function is run. If the value is null or undefined, it will default
 * to the global object.
 *
 * @returns {function} A partially-applied form of the speficied function.
 */
this.BindToObject = function BindToObject(fn, self, opt_args) {
  var boundargs = fn.boundArgs_ || [];
  boundargs = boundargs.concat(Array.slice(arguments, 2, arguments.length));

  if (fn.boundSelf_)
    self = fn.boundSelf_;
  if (fn.boundFn_)
    fn = fn.boundFn_;

  var newfn = function() {
    // Combine the static args and the new args into one big array
    var args = boundargs.concat(Array.slice(arguments));
    return fn.apply(self, args);
  }

  newfn.boundArgs_ = boundargs;
  newfn.boundSelf_ = self;
  newfn.boundFn_ = fn;

  return newfn;
}