My Y-Combinator example

ycombinator.js

/*
First group takes a function and returns a 
function that calls a function with an 
argument
*/
(function (ycomb) {
    return (function(n){
        return ycomb(ycomb)(n);
    });
/*
Second group is the function passed to the 
recursive combinator. 
*/
})(function (self) {

/*
This is the part that you're working with
that becomes your recursive function.
*/
    return function (x) {
        if ( x > 0 ) {
            console.log(x);
/*
It's really important that the value you 
return is a function that calls it's self
that passes the next set of arguments
*/
            return self(self)(x-1);
        }
    };
/*
And this is your input value
*/
})(5);


/*
Notes: You could always abstract away
most of the ceremony for this, should
you ever need to use a y-combinator I
would advise you do so.

Uses: Really, the only time you're going 
to use this is when you're programming
a function that is anonymous and you 
cannot expose any variables to a higher
scope.

Warning: Most people will never encounter
this in JavaScript. Also, beware that
Internet Explorer 6, 7, 8 all run 
"JScript" not JavaScript, and it will
hoist all anonymous functions into a global
namespace. This is resolved with IE9.

*/