[Haskell-cafe] Re: [Haskell] ANN: Catch (first ever release)

[Neil Mitchell]

Following up on haskell-cafe:

Hi Chris,

> >  For the last few years I've been working on a pattern-match checker
> > for Haskell, named Catch. I'm now happy to make a release:
> I would love to use this with regex-tdfa (and the other regex-* modules).
>
> At the moment regex-tdfa is uses a few extensions such as recursive "mdo"
> notation and parts hook up to the MPTC + fundeps used in regex-base.  The
> MPTC+fundeps are not part of the workhorse modules, they are just "type class
> syntactic sugar" that makes it easier for the library consumer.  But "mdo" _is_
> used in two of the important internal functions.

You have several options:

* Wait until GHC Core is working, when Catch will work with all these
things automatically.

* Rewrite your code to eliminate mdo, if you wish to port regex to Yhc
you will need to do this anyway.

* Find an mdo preprocessor (I think one exists?) and preprocess the
code before checking.

Obviously the GHC Core one is least work for you, but won't be
available for a while.

Thanks

Neil