Add missing Semigroup instance to `Constant` functor (fixes #44)
authorRoss Paterson <ross@soi.city.ac.uk>
Sat, 2 Sep 2017 08:55:03 +0000 (08:55 +0000)
committerRoss Paterson <ross@soi.city.ac.uk>
Sat, 2 Sep 2017 08:55:03 +0000 (08:55 +0000)
commite1a9a28ee18fe799d0ad749ed8afc8affb8661c1
treeb5f9728843435a6f3f5e04b72c82151402bac9bf
parentdc91f38b4f961083b790c85c90a4791c19f438f5
Add missing Semigroup instance to `Constant` functor (fixes #44)

From Herbert Valerio Riedel

This is needed for moving forward with
https://prime.haskell.org/wiki/Libraries/Proposals/SemigroupMonoid
Data/Functor/Constant.hs