Data instances for MTL types
ross at soi.city.ac.uk
Fri Jan 16 08:37:57 EST 2009
On Thu, Jan 15, 2009 at 10:46:46PM +0100, Henning Thielemann wrote:
> When trying to perform some tests with StrictCheck, I found that the
> monads from the 'transformers' package don't have Data instances. Can
> they be provided while keeping 'transformers' Haskell 98 and avoiding
> orphan instances?
The Typeable and Data instances will be non-trivial, as they can't be
derived for higher-order type constructors.
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