Add getAndModify to StrictStateT

christiaanb · May 23, 2011 · 5172288 · 5172288
1 parent 9d142a4
commit 5172288
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/clash/Data/Accessor/Monad/Trans/StrictState.hs b/clash/Data/Accessor/Monad/Trans/StrictState.hs
@@ -14,6 +14,12 @@ get f = State.gets (Accessor.get f)
 modify :: Monad m => Accessor.T r a -> (a -> a) -> StateT r m ()
 modify f g = State.modify (Accessor.modify f g)
 
+getAndModify :: Monad m => Accessor.T r a -> (a -> a) -> StateT r m a
+getAndModify f g =
+   do x <- get f
+      modify f g
+      return x
+
 infix 1 %=, %:
 
 (%=) :: Monad m => Accessor.T r a -> a -> StateT r m ()