Currying is an expressive and compact alternative to manually wrapping anonymous functions. I use it a lot. But sometimes its not enough – the problem is you can only pre-assign the first n arguments. What if we wanted to make a function and pre-assign th

Partial.js

//from http://javascriptweblog.wordpress.com/2010/05/17/partial-currys-flashy-cousin/

window.___ = {}; //argument placeholder

Function.prototype.partial = function() {
    if (arguments.length<1) {
        return this; //nothing to pre-assign - return the function as is
    }
    var __method = this;
    var args = arguments;
    return function() {
        //build up new arg list, for placeholders use current arg, otherwise copy original args
        var argIndex = 0, myArgs = [];
        for (var i = 0; i < args.length; i++) {
            myArgs[i] = window.___==args[i] ? arguments[argIndex++] : args[i];
        }
        return __method.apply(this, myArgs);
    }
}

//eg. Define a remove function:-

String.prototype.remove = String.prototype.replace.partial(___,'');

"12654I 2am2 13not12 3a45 3number3 453".remove(/\d/gi); //"I am not a number"