Re: [Haskell-cafe] If you'd design a Haskell-like language, what would you do different?

Отправлено с iPad 22.12.2011, в 23:56, Conor McBride написал(а):

I'd be glad if "pure" meant "total", but partiality were an effect supported by the run-time system. Then we could choose to restrict ourselves, but we wouldn't be restricted by the language.

I second that. Having a special "partiality" monad would be nice. However, I'm not certain as to how it would interact with recursion — if f is a total function, fix f could be (and almost certainly would be) a possibly undiefined value. So, fix should have type "(a -> a) -> Partial a"; that's OK, but implicit uses of fix (I mean let statements) would be quite different.

I'd like to program with an applicative notion, but in monadic types. That's what I'd do different, and for me, the subject is not a hypothetical question.

So... you are developing a programming language with all calculations being automatically lifted to a monad? What if we want to do calculations with monadic values themselves, like, for example, store a few monadic calculations in a list (without joining all there effects as the sequence function does)?