> exist.hs:73:
> My brain just exploded.
> I can't handle pattern bindings for existentially-quantified
constructors.
It was my brain. (Though I discussed it with Mark, and I think
Hugs may have a similar restriction.)
> data GenPic = forall pot. (PictureObject pot) => MkGenPic pot
> main :: IO ()
> main = do
> putStr $ getPictureName obj
> where MkGenPic obj = item
> item = head obj_list
The problem is the pattern binding for MkGenPic. Try
main = case item of
MkGenPic obj -> do putStr (getPictureName item)
where
item = head obj_list
I'll be interested to see if this happens a lot.
Simon
