On Wed, Jun 9, 2010 at 12:33 PM, Martin Drautzburg
So far so good. However my "Named" things are all functions and I don't see I ever want to map over any of them. But what I'd like to do is use them like ordinary functions as in:
f::Named (Int->Int) f x
Is there a way to do this, other than writing
apply::Named Int ->Int apply n x = (val_of n) x
What's wrong with that? (Other than the type signature, but I get what you mean). The proper type signature is apply :: Named (Int -> Int) -> Int -> Int. You don't need the parentheses: apply n x = val_of n x Or just: apply = val_of I frequently suggest the following to new Haskellers: don't worry so much about notation. Sometimes programmers get a picture in their heads about how the code *should* look, and then they go through all manner of ugly contortions to make the notation right. I suggest that you will encounter much less pain if you accept Haskell's straightforward notation, and focus on the meaning rather than the syntax of your program. So, to summarize: if you have something that isn't a function and you want to use it like a function, convert it to a function (using another function :-P). That's all. No syntax magic, just say what you're doing. Luke