[prev in list] [next in list] [prev in thread] [next in thread] 

List:       haskell-beginners
Subject:    Re: [Haskell-beginners] =?utf-8?q?How_to_avoid_repeating_a=09type=09r?=
From:       gs <voldermort () hotmail ! com>
Date:       2013-04-25 8:03:25
Message-ID: loom.20130425T095448-755 () post ! gmane ! org
[Download RAW message or body]

Daniel Fischer <daniel.is.fischer <at> googlemail.com> writes:

> ...

You've mentioned GADT a few times, but I can't find a case where it's
different to regular datatypes.

data Foo a = Eq a => Foo a

seems to have the same effect as

data Foo a where
   Foo a :: Eq a => a -> Foo a

Both remember the Eq constraint if I pattern match on the constructor, and
both ignore it otherwise.


_______________________________________________
Beginners mailing list
Beginners@haskell.org
http://www.haskell.org/mailman/listinfo/beginners
[prev in list] [next in list] [prev in thread] [next in thread]