Create NonEmptyMap type

Author: Ericson2314

containers-tests/benchmarks/LookupGE/LookupGE_Map.hs

@@ -14,7 +14,7 @@ lookupGE2 :: Ord k => k -> Map k a -> Maybe (k,a)
 lookupGE2 = go
   where
     go !_ Tip = Nothing
-    go !k (Bin _ kx x l r) =
+    go !k (NE (Bin _ kx x l r)) =
         case compare k kx of
             LT -> case go k l of
                     Nothing -> Just (kx,x)
@@ -27,7 +27,7 @@ lookupGE3 :: Ord k => k -> Map k a -> Maybe (k,a)
 lookupGE3 = go Nothing
   where
     go def !_ Tip = def
-    go def !k (Bin _ kx x l r) =
+    go def !k (NE (Bin _ kx x l r)) =
         case compare k kx of
             LT -> go (Just (kx,x)) k l
             GT -> go def k r
@@ -38,26 +38,26 @@ lookupGE4 :: Ord k => k -> Map k a -> Maybe (k,a)
 lookupGE4 k = k `seq` goNothing
   where
     goNothing Tip = Nothing
-    goNothing (Bin _ kx x l r) = case compare k kx of
-                                   LT -> goJust kx x l
-                                   EQ -> Just (kx, x)
-                                   GT -> goNothing r
+    goNothing (NE (Bin _ kx x l r)) = case compare k kx of
+        LT -> goJust kx x l
+        EQ -> Just (kx, x)
+        GT -> goNothing r
 
     goJust ky y Tip = Just (ky, y)
-    goJust ky y (Bin _ kx x l r) = case compare k kx of
-                                     LT -> goJust kx x l
-                                     EQ -> Just (kx, x)
-                                     GT -> goJust ky y r
+    goJust ky y (NE (Bin _ kx x l r)) = case compare k kx of
+        LT -> goJust kx x l
+        EQ -> Just (kx, x)
+        GT -> goJust ky y r
 {-# INLINABLE lookupGE4 #-}
 
 -------------------------------------------------------------------------------
 -- Utilities
 -------------------------------------------------------------------------------
 
 findMinMaybe :: Map k a -> Maybe (k,a)
-findMinMaybe (Bin _ kx x Tip _)  = Just (kx,x)
-findMinMaybe (Bin _ _  _ l _)    = findMinMaybe l
-findMinMaybe Tip                 = Nothing
+findMinMaybe (NE (Bin _ kx x Tip _))  = Just (kx,x)
+findMinMaybe (NE (Bin _ _  _ l _))    = findMinMaybe l
+findMinMaybe Tip                               = Nothing
 
 #ifdef TESTING
 -------------------------------------------------------------------------------