diff options
| author | aarne <aarne@cs.chalmers.se> | 2008-06-25 16:54:35 +0000 |
|---|---|---|
| committer | aarne <aarne@cs.chalmers.se> | 2008-06-25 16:54:35 +0000 |
| commit | e9e80fc389365e24d4300d7d5390c7d833a96c50 (patch) | |
| tree | f0b58473adaa670bd8fc52ada419d8cad470ee03 /src/tools/c/GFCC/ComposOp.hs | |
| parent | b96b36f43de3e2f8b58d5f539daa6f6d47f25870 (diff) | |
changed names of resource-1.3; added a note on homepage on release
Diffstat (limited to 'src/tools/c/GFCC/ComposOp.hs')
| -rw-r--r-- | src/tools/c/GFCC/ComposOp.hs | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/tools/c/GFCC/ComposOp.hs b/src/tools/c/GFCC/ComposOp.hs new file mode 100644 index 000000000..401c1d778 --- /dev/null +++ b/src/tools/c/GFCC/ComposOp.hs @@ -0,0 +1,30 @@ +{-# OPTIONS_GHC -fglasgow-exts #-} +module GFCC.ComposOp (Compos(..),composOp,composOpM,composOpM_,composOpMonoid, + composOpMPlus,composOpFold) where + +import Control.Monad.Identity +import Data.Monoid + +class Compos t where + compos :: (forall a. a -> m a) -> (forall a b. m (a -> b) -> m a -> m b) + -> (forall a. t a -> m (t a)) -> t c -> m (t c) + +composOp :: Compos t => (forall a. t a -> t a) -> t c -> t c +composOp f = runIdentity . composOpM (Identity . f) + +composOpM :: (Compos t, Monad m) => (forall a. t a -> m (t a)) -> t c -> m (t c) +composOpM = compos return ap + +composOpM_ :: (Compos t, Monad m) => (forall a. t a -> m ()) -> t c -> m () +composOpM_ = composOpFold (return ()) (>>) + +composOpMonoid :: (Compos t, Monoid m) => (forall a. t a -> m) -> t c -> m +composOpMonoid = composOpFold mempty mappend + +composOpMPlus :: (Compos t, MonadPlus m) => (forall a. t a -> m b) -> t c -> m b +composOpMPlus = composOpFold mzero mplus + +composOpFold :: Compos t => b -> (b -> b -> b) -> (forall a. t a -> b) -> t c -> b +composOpFold z c f = unC . compos (\_ -> C z) (\(C x) (C y) -> C (c x y)) (C . f) + +newtype C b a = C { unC :: b } |
