I don't think you can: http://www.mail-archive.com/haskell-cafe@haskell.org/msg13057.html I've also looked at the reify function in the latest version of TH and there seems to be no way of reifying instances. /Jonas On 22 April 2010 22:33, Dmitry Olshansky wrote:

Hello cafe,

Could you say can I determine in Template Haskell that datatype X has instance of class Y?

Regards, Dmitry _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe