At 2001-01-30 02:37, Fergus Henderson wrote:

>class BaseClass s where
>       downcast_to_derived :: s -> Maybe Derived

Exactly what I was trying to avoid, since now every base class needs to 
know about every derived class. This isn't really a practical way to 
build an extensible type hierarchy.

-- 
Ashley Yakeley, Seattle WA


_______________________________________________
Haskell-Cafe mailing list
[EMAIL PROTECTED]
http://www.haskell.org/mailman/listinfo/haskell-cafe

Reply via email to