proposed change to transformers package

Ross Paterson ross at
Fri Mar 26 15:28:18 EDT 2010

On Fri, Mar 26, 2010 at 05:24:18AM -0700, Nicolas Pouillard wrote:
> Could we have functors products, sums, fixpoints as well? It would really
> avoid to redefine them each time.

Do you mean

  data Product f g a = Product (f a) (g a)

with Functor, Foldable, Traversable and Applicative instances?
Not sure if the other two count as transformers.

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