[Haskell-cafe] Classes in type declarations in Hugs
John Goerzen
jgoerzen at complete.org
Fri Dec 3 12:16:19 EST 2004
On Fri, Dec 03, 2004 at 11:59:23AM -0500, Scott Turner wrote:
> On 2004 November 30 Tuesday 11:04, John Goerzen wrote:
> > type CPResult a = MonadError CPError m => m a
>
> You've got an existential type here. (Was that the intent?)
Yes. It was so that I could make the return types of some various
functions easier to type and deal with. Problem with using a data type
is that the result is no longer directly in MonadError, nor usable as an
Either. I wound up just manually expanding it. Thanks, though, for the
feedback.
-- John
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