Type Families and defaults

Mitar mmitar at gmail.com
Sun Sep 5 23:02:19 EDT 2010


Hi!

I see here:

http://hackage.haskell.org/trac/ghc/wiki/TypeFunctionsStatus

That defaults in type families are not yet implemented. But how far is this?

And how far is overall implementation of this? There seems to be a lot
of open bugs around that? Are type families meant to be used or is
that still an experimental feature?

For example, I have problems type checking the attached code
(Test.hs). Is there a way to define a default function as I envisioned
it? Or is this just broken code? ;-)

It seems it is the later as also version with dependencies does not
work (Test2.hs).

Best regards


Mitar
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