[Haskell-cafe] Error on instance of Control.Exception.Exception

Maurí­cio briqueabraque at yahoo.com
Sun Feb 22 19:41:37 EST 2009


I read here:


that this is declared:

class (Typeable e, Show e) => Exception e where
   toException :: e -> SomeException
   fromException :: SomeException -> Maybe e

I understand this means Excepton is a class. But
after I try:

instance Exception DbError where

GHC says:

Type constructor `Exception' used as a class
In the instance declaration for `Exception DbError'

Isn't Exception a class? If it is, what is the proper
way to have an Exception instance for my type?


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