[Haskell-cafe] Declaring variance of class parameters?

2007-02-27 Thread Jacques Carette
If I have a class, say class Symantics repr where int:: Int - repr Int and so on, I would like to *require* that 'repr' be covariant. Is there any way to do that? Jacques ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org

Re: [Haskell-cafe] Declaring variance of class parameters?

2007-02-27 Thread Ross Paterson
On Tue, Feb 27, 2007 at 02:00:29PM -0500, Jacques Carette wrote: If I have a class, say class Symantics repr where int:: Int - repr Int and so on, I would like to *require* that 'repr' be covariant. Is there any way to do that? class Functor repr = Symantics repr would be