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Diffstat (limited to 'libraries/base/Control/Monad/Zip.hs')
| -rw-r--r-- | libraries/base/Control/Monad/Zip.hs | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/libraries/base/Control/Monad/Zip.hs b/libraries/base/Control/Monad/Zip.hs index 1f63cab3d7..771b8aa9c6 100644 --- a/libraries/base/Control/Monad/Zip.hs +++ b/libraries/base/Control/Monad/Zip.hs @@ -1,4 +1,5 @@ {-# LANGUAGE Safe #-} +{-# LANGUAGE TypeOperators #-} ----------------------------------------------------------------------------- -- | @@ -19,6 +20,7 @@ module Control.Monad.Zip where import Control.Monad (liftM, liftM2) import Data.Monoid +import GHC.Generics -- | `MonadZip` type class. Minimal definition: `mzip` or `mzipWith` -- @@ -75,3 +77,16 @@ instance MonadZip Last where instance MonadZip f => MonadZip (Alt f) where mzipWith f (Alt ma) (Alt mb) = Alt (mzipWith f ma mb) + +-- Instances for GHC.Generics +instance MonadZip Par1 where + mzipWith = liftM2 + +instance MonadZip f => MonadZip (Rec1 f) where + mzipWith f (Rec1 fa) (Rec1 fb) = Rec1 (mzipWith f fa fb) + +instance MonadZip f => MonadZip (M1 i c f) where + mzipWith f (M1 fa) (M1 fb) = M1 (mzipWith f fa fb) + +instance (MonadZip f, MonadZip g) => MonadZip (f :*: g) where + mzipWith f (x1 :*: y1) (x2 :*: y2) = mzipWith f x1 x2 :*: mzipWith f y1 y2 |