Would an _.if function be useful?

[mattdiamond]

_.if would take two arguments, a primary function and a conditional function. It would return a new function that, when called, will call the primary function only if the conditional (called with the same arguments) returns a truthy value. It would look something like this:

_.if = function(func, condition){
    return function(){
        if (condition.apply(this, arguments)){
            return func.apply(this, arguments);
        }
    }
};

This way you can write generic functions and then easily add conditions for execution when passing them to iterators. Something like:

items.forEach(_(processItem).if(isNotProcessed));

Would this be a useful addition?

[jgonggrijp]

I don't think being deemed "useful" is a hard condition for entry into Contrib, as Contrib is in part a testing ground to see whether people actually end up using a function (@joshuacc please correct me if I'm wrong).

That said: I can't predict whether people will find this useful, but the idea seems interesting in any case.