[Haskell-cafe] Equality constraints in type families

[Wolfgang Jeltsch]

Am Donnerstag, 27. März 2008 22:43 schrieb Wolfgang Jeltsch:
> Am Mittwoch, 26. März 2008 03:07 schrieb Hugo Pacheco:
> > > The extra syntax has its advantages (more local information) and
> > > disadvantages (more clutter).  We weren't convinced that we need the
> > > extra syntax, so left it out for the moment. However, this is
> > > something that can always be changed if experience shows that programs
> > > are easier to understand with extra syntax.  It doesn't affect the
> > > type theory and is really a pure language design question.  I'd be
> > > glad to hear some more opinions about this matter.
> >
> > I would go for the braces as Claus suggested,
>
> I would do so, too.

Hmm, but then we should also introduce braces for ordinary type synonyms:

    type ReaderWriterT m = ReaderT (WriterT m)

    x :: {ReaderWriterT IO} Char

> […]

Best wishes,
Wolfgang