Added Semigroup instance.haskell

2 files changed, 6 insertions, 0 deletions

diff --git a/haskell/Data/VCDIFF.hs b/haskell/Data/VCDIFF.hs
index fe4cc98..db75fb1 100644
--- a/haskell/Data/VCDIFF.hs
+++ b/haskell/Data/VCDIFF.hs
@@ -273,6 +273,9 @@ data Result x = Result
                   -- is an error code and message indicating what.
     } deriving (Show,Functor)
 
+instance Semigroup x => Semigroup (Result x) where
+    Result x xe <> y = Result (x <> result y) (maybe (resultError y) Just xe)
+
 instance Monoid x => Monoid (Result x) where
     mempty = Result mempty Nothing
     mappend (Result x xe) y = Result (mappend x $ result y) (maybe (resultError y) Just xe)
diff --git a/haskell/Data/VCDIFF/Types.hsc b/haskell/Data/VCDIFF/Types.hsc
index 015f406..54237b8 100644
--- a/haskell/Data/VCDIFF/Types.hsc
+++ b/haskell/Data/VCDIFF/Types.hsc
@@ -167,6 +167,9 @@ pattern XD3_COMPLEVEL_3     = Flags (#const XD3_COMPLEVEL_3)
 pattern XD3_COMPLEVEL_6     = Flags (#const XD3_COMPLEVEL_6)
 pattern XD3_COMPLEVEL_9     = Flags (#const XD3_COMPLEVEL_9)
 
+instance Semigroup Flags where
+    Flags a <> Flags b = Flags (a .|. b)
+
 instance Monoid Flags where
     mempty = Flags 0
     Flags a `mappend` Flags b = Flags (a .|. b)