Mapping 1.0.0.0 → 2.0.0.0

raw patch · 2 files changed

+7/−7 lines, 2 files

Files

• Mapping.cabal +1/−1
• Mapping.hs +6/−6

@@ -2,7 +2,7 @@ -- documentation, see http://haskell.org/cabal/users-guide/  name:                Mapping-version:             1.0.0.0+version:             2.0.0.0 synopsis:            Mapping -- description:          homepage:            https://github.com/zaoqi/Mapping.hs

@@ -29,13 +29,13 @@  data Mapping k v = MappingNil | MappingNode (Mapping k v) k v (Mapping k v) deriving Show -mappingRef :: Ord k => Mapping k v -> k -> v -> v-mappingRef (MappingNode l mk v r) k d =+mappingRef :: Ord k => Mapping k v -> k -> Maybe v+mappingRef (MappingNode l mk v r) k =     case compare k mk of-        LT -> mappingRef l k d-        EQ -> v-        GT -> mappingRef r k d-mappingRef MappingNil _ d = d+        LT -> mappingRef l k+        EQ -> Just v+        GT -> mappingRef r k+mappingRef MappingNil _ = Nothing  mappingSet :: Ord k => Mapping k v -> k -> v -> Mapping k v mappingSet (MappingNode l mk mv r) k v =