Re: Pattern match errors in do?

"Neil Mitchell" <[email protected]> Wed, 5 Jul 2006 22:41:47 +0100
Newsgroups gmane.comp.lang.haskell.hat
Message-ID <[email protected]>
Hi,

> A pattern match failure in a "do" will call "fail" (not "error" as other
> pattern match failures do). This is the "fail" of the IO monad, which
> calls "ioError".

I believe according to Haskell 98, fail in the IO monad calls error -
its only recent extension to GHC/Hugs which have resulted in ioError
and exceptions. Perhaps for the purposes of hat stuff, error should be
called instead? At least until a proper exception story can be
developed.

Thanks

Neil