[Haskell] Re: Overloading show
karczma at info.unicaen.fr
Fri Sep 10 18:54:07 EDT 2004
Stephan Zaubzer writes:
> Here my attempts:
> data Entry a = EmptyEntry | MakeEntry a a
> showEntry :: (Show a) => Entry a -> String
> showEntry EmptyEntry = "Empty"
> showEntry MakeEntry a b = show a ++ ": " ++ show b
> what am I doing wrong? I have seen this way on some tutorials.
I believe that if you looked cautiously at the system response
you would guess yourself.
Parentheses missing, it should be
showEntry (MakeEntry a b) = ...
... who has a pleasure of correcting thousands students' programs
per year, so this kind of error burns his eyes...
More information about the Haskell