default-parameter.js

A experimental default values for function parameters in Javascript, that just uses arguments.callee and arguments.caller

This is just an experimental project, that shows how arguments.callee and arguments.caller could be used in real world applications to make programmers life easier.

Frankly speaking I would add an parameter in the arguments that allows you to get the context of the function, this way we could create very powerfull stuffs like this project.

The ideia is to have a function that goes inside any function, and you can easy create default values for the function parameters.

Usage

To use you need to wrap 3 lines code in any function:

if(arguments.length < arguments.callee.length){
  return defaults.call(this, /* default values, separeted by comma */);
}

Or you can use an array as second parameter using apply instead call.

if(arguments.length < arguments.callee.length){
  return defaults.apply(this, /* default values in array [arg1, arg2, arg3...] */);
}

Example

function abc(a, b, c){
  if(arguments.length < arguments.callee.length){
    return defaults.call(this, 'a',{e: 1, f: 2, g: 3},'c');
  }
  return [a,b,c];
}

Tests:

abc();
// ["a", { e:1, f:2, g:3 }, "c"]

abc('d');
// ["d", { e:1, f:2, g:3 }, "c"]

abc(null, {e:'e'});
// [null, { e:'e', f:2, g:3 }, "c"]

Compatibility

Any browser if you don't use strict mode.