On Mon, Jul 13, 2009 at 10:33 PM, Ashley Yakeley <ashley@semantic.org> wrote:

On Mon, 2009-07-13 at 23:20 -0700, Jason Dagit wrote:
> data EqualType a b where
> MkEqualType :: EqualType t t
>
> Is there any reason to prefer this over:
> data EqualType a b where
> MkEqualType :: EqualType a a

They're exactly the same. Yours just looks a bit "left-biased", that's
all.

For GADTs I prefer the kind color:

data EqualType :: * -> * -> * where

MkEqualType :: EqualType a a

Except I don't usually use it, because I mostly use GADT syntax pedagogically, as introduction to algebraic data types, and introducing kinds just seems to confuse things further.

Luke