How do you curry any javascript function of arbitrary arity?

Question

Let\'s say I have some function:

function g(a,b,c){ return a + b + c }

And I\'d like to turn it into its \"curried\" form (in quotations si

Answer 1

Here's my attempt:

function curry(fn, len) {
    if (typeof len != "number")
        len = fn.length; // getting arity from function
    return function curried() {
        var rlen = len - arguments.length;
        if (rlen <= 0) // then execute now
            return fn.apply(this, arguments);
        // else create curried, partially bound function:
        var bargs = [this]; // arguments for `bind`
        bargs.push.apply(bargs, arguments);
        return curry(fn.bind.apply(fn, bargs), rlen);
    };
}

This does not partial application (which is easy in JS with the bind method), but true functional currying. It works with any functions of arbitrary, but fixed arity. For variadic functions you would need a different execution trigger, maybe when no arguments are passed any more or an exec method like in @plalx' answer.