diff options
| author | PhilFreeman <> | 2014-03-29 16:11:00 (GMT) |
|---|---|---|
| committer | hdiff <hdiff@hdiff.luite.com> | 2014-03-29 16:11:00 (GMT) |
| commit | 11d05310d58784661ca891c7ce828e81496763f0 (patch) | |
| tree | cd5c099107571162066b348bb51aed76475206ca | |
| parent | 765bd6db09e13546e02b6858beaec98963233027 (diff) | |
| -rw-r--r-- | pattern-arrows.cabal | 2 | ||||
| -rw-r--r-- | src/Control/PatternArrows.hs | 6 |
2 files changed, 6 insertions, 2 deletions
diff --git a/pattern-arrows.cabal b/pattern-arrows.cabal index 13e9805..5934e30 100644 --- a/pattern-arrows.cabal +++ b/pattern-arrows.cabal @@ -1,5 +1,5 @@ name: pattern-arrows -version: 0.0.1 +version: 0.0.2 cabal-version: >=1.4 build-type: Simple license: MIT diff --git a/src/Control/PatternArrows.hs b/src/Control/PatternArrows.hs index c42d5d6..d382c19 100644 --- a/src/Control/PatternArrows.hs +++ b/src/Control/PatternArrows.hs @@ -29,7 +29,11 @@ import Control.Arrow ((***), (<+>)) -- -- A pattern is a Kleisli arrow for the @StateT Maybe@ monad. That is, patterns can fail, and can carry user-defined state. -- -newtype Pattern u a b = Pattern { runPattern :: A.Kleisli (StateT u Maybe) a b } deriving (C.Category, A.Arrow, A.ArrowZero, A.ArrowPlus) +newtype Pattern u a b = Pattern { runPattern :: A.Kleisli (StateT u Maybe) a b } deriving (A.Arrow, A.ArrowZero, A.ArrowPlus) + +instance C.Category (Pattern u) where + id = Pattern (C.id) + Pattern p1 . Pattern p2 = Pattern (p1 C.. p2) instance Functor (Pattern u a) where fmap f (Pattern p) = Pattern $ A.Kleisli $ fmap f . A.runKleisli p |