Using bind for partial application without affecting the receiver

Question

If I want to partially apply a function I can use bind , but it seems I have to affect the receiver of the function (the first argument to bind ). Is this correct?

I want to perform partial application using bind without affecting the receiver.

myFunction.bind(iDontWantThis, arg1); // I dont want to affect the receiver

Answer 1

partial application using bind without affecting the receiver

That's not possible. bind was explicitly designed to partially apply the "zeroth argument" - the this value, and optionally more arguments. If you only want to fix the first (and potentially more) parameters of your function, but leave this unbound, you'll need to use a different function:

Function.prototype.partial = function() {
    if (arguments.length == 0)
        return this;
    var fn = this,
        args = Array.prototype.slice.call(arguments);
    return function() {
        return fn.apply(this, args.concat(Array.prototype.slice.call(arguments)));
    };
};

Of course, such a function is also available in many libraries, eg Underscore , Lodash , Ramda etc. There is no native equivalent however.