How would a specific type override car to do something else? Wouldn't car of queues simply return the entire contents rather than the top element[1]? What if I want car of a queue to return the top element? Or am I missing something?
I think waterhouse was saying that built-in functions would auto-unwrap their arguments by default, but it would just be a default, and you could override it with custom behaviors if you wanted to.
"If desired, you could add polymorphism--redefine + to dispatch on numbers tagged as numbers mod 7 or something, which it would discover by calling "type" on it before stripping off the tag. However, the strong default would be to treat it like the thing that it is --when "car" is called on the "fn"-tagged list, it's probably being called by "ar-apply", which knows exactly what it's doing and would like "car" to shut up and give me the car, thank you."
I guess in a way, this is another suggestion to add a default behavior for something that is currently an error, like letting the function call (1 2 3) return the list (1 2 3). But then waterhouse probably doesn't have that motive in mind, considering the opinions expressed at http://arclanguage.org/item?id=12841 and http://arclanguage.org/item?id=13827, so it's probably just a side effect, for better or worse. ^_^
Yes, except I don't think this solves my criticism. It still seems like a good idea to get rid of rep, though. They're orthogonal concepts, and both ideas can be used at once.
Then again, if you're going the route of attaching arbitrary tags to objects... might as well go the full message passing approach, which is what Arubic is doing.
