module Darcs.Patch.Effect ( Effect(..) ) where
import Darcs.Patch.Prim.Class ( PrimOf )
import Darcs.Witnesses.Ordered
( FL(..), RL(..), reverseFL, reverseRL
, concatFL, concatRL, mapFL_FL, mapRL_RL
)
#include "gadts.h"
class Effect p where
effect :: p C(x y) -> FL (PrimOf p) C(x y)
effect = reverseRL . effectRL
effectRL :: p C(x y) -> RL (PrimOf p) C(x y)
effectRL = reverseFL . effect
instance Effect p => Effect (FL p) where
effect p = concatFL $ mapFL_FL effect p
effectRL p = concatRL $ mapRL_RL effectRL $ reverseFL p
instance Effect p => Effect (RL p) where
effect p = concatFL $ mapFL_FL effect $ reverseRL p
effectRL p = concatRL $ mapRL_RL effectRL p