Bang patterns and splices in lambdas

data/examples/declaration/value/function/lambda-single-line-out.hs

@@ -7,3 +7,9 @@ bar x =
 
 baz :: a -> a -> a
 baz = \ ~x ~y -> x
+
+zag :: a -> a -> a
+zag = \ !x !y -> x
+
+spl :: a -> a
+spl = \ $([p|x|]) -> x

data/examples/declaration/value/function/lambda-single-line.hs

@@ -7,3 +7,9 @@ bar x =
 
 baz :: a -> a -> a
 baz = \ ~x  ~y -> x
+
+zag :: a -> a -> a
+zag = \ !x  !y -> x
+
+spl :: a -> a
+spl = \ $([p|x|]) -> x

src/Ormolu/Printer/Meat/Declaration/Value.hs

@@ -135,9 +135,12 @@ p_match' placer pretty style isInfix m_pats m_grhss = do
           PatternBind -> stdCase
           Case -> stdCase
           Lambda -> do
-            case unLoc (NE.head ne_pats) of
+            let needsSpace = case unLoc (NE.head ne_pats) of
-              LazyPat _ _ -> txt "\\ "
+                  LazyPat _ _ -> True
-              _ -> txt "\\"
+                  BangPat _ _ -> True
+                  SplicePat _ _ -> True
+                  _ -> False
+            txt (if needsSpace then "\\ " else "\\")
             stdCase
           LambdaCase -> stdCase
       return inci'