On Thu, Apr 25, 2013 at 6:36 PM, Joe Quinn <headprogrammingczar@gmail.com> wrote:

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

is equivalent to

data Foo a = Eq a => Foo a

but is different from

data Eq a => Foo a = Foo a

(Yup, tripped up a few of us already!)

-- Kim-Ee