[Haskell-cafe] Typeclasses and instances

Mark Carroll mark at ixod.org
Thu Mar 17 11:04:52 EST 2005

> 	newtype Floating a => Vector a = Vector [a]

Okay, I now know a little more about this, with help from friends. The
obvious Functor instance seems not to work with GHC 6.2.2 but does work
with GHC 6.4. With 6.2.2 I can still use GHC's newtype-deriving extension
to derive an instance for Functor, I'm just not sure how I can get an
explicit instance past 6.2.2 without it complaining about my syntax or not
being able to deduce Floating a or b. This isn't a show stopper, I'm just

-- Mark

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