Answer to https://gist.github.com/rmurphey/576723 for say('Hello')('world!'); question, but in a very custom way.

say

function say(a){
    var inner = function(b){
        return say(a+b);
    };
    
    inner.toString = function(){
        return a;
    };
    
    return inner;
}

console.log(say('h'));/will log h
console.log(say('hello')('world');//will log helloworld
console.log(say('h')('e')('l')('l')('o')(' ')('w')('o')('r')('l')('d')('!'));//you know what it will do ;-)