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1. mapWhenMatched :: forall (f :: Type -> Type) a b x y . Functor f => (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b

   ghc	GHC.Data.Word64Map.Internal

   Map covariantly over a WhenMatched f x y.

2. mapWhenMissing :: forall (f :: Type -> Type) a b x . (Applicative f, Monad f) => (a -> b) -> WhenMissing f x a -> WhenMissing f x b

   ghc	GHC.Data.Word64Map.Internal

   Map covariantly over a WhenMissing f x.

3. mapWithKey :: (Key -> a -> b) -> Word64Map a -> Word64Map b

   ghc	GHC.Data.Word64Map.Internal

   Map a function over all values in the map.

   let f key x = (show key) ++ ":" ++ x
   mapWithKey f (fromList [(5,"a"), (3,"b")]) == fromList [(3, "3:b"), (5, "5:a")]
   

4. mapAccum :: (a -> b -> (a, c)) -> a -> Word64Map b -> (a, Word64Map c)

   ghc	GHC.Data.Word64Map.Lazy

   The function mapAccum threads an accumulating argument through the map in ascending order of keys.

   let f a b = (a ++ b, b ++ "X")
   mapAccum f "Everything: " (fromList [(5,"a"), (3,"b")]) == ("Everything: ba", fromList [(3, "bX"), (5, "aX")])
   

5. mapAccumRWithKey :: (a -> Key -> b -> (a, c)) -> a -> Word64Map b -> (a, Word64Map c)

   ghc	GHC.Data.Word64Map.Lazy

   The function mapAccumRWithKey threads an accumulating argument through the map in descending order of keys.

6. mapAccumWithKey :: (a -> Key -> b -> (a, c)) -> a -> Word64Map b -> (a, Word64Map c)

   ghc	GHC.Data.Word64Map.Lazy

   The function mapAccumWithKey threads an accumulating argument through the map in ascending order of keys.

   let f a k b = (a ++ " " ++ (show k) ++ "-" ++ b, b ++ "X")
   mapAccumWithKey f "Everything:" (fromList [(5,"a"), (3,"b")]) == ("Everything: 3-b 5-a", fromList [(3, "bX"), (5, "aX")])
   

7. mapEither :: (a -> Either b c) -> Word64Map a -> (Word64Map b, Word64Map c)

   ghc	GHC.Data.Word64Map.Lazy

   Map values and separate the Left and Right results.

   let f a = if a < "c" then Left a else Right a
   mapEither f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])
   == (fromList [(3,"b"), (5,"a")], fromList [(1,"x"), (7,"z")])
   
   mapEither (\ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])
   == (empty, fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])
   

8. mapEitherWithKey :: (Key -> a -> Either b c) -> Word64Map a -> (Word64Map b, Word64Map c)

   ghc	GHC.Data.Word64Map.Lazy

   Map keys/values and separate the Left and Right results.

   let f k a = if k < 5 then Left (k * 2) else Right (a ++ a)
   mapEitherWithKey f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])
   == (fromList [(1,2), (3,6)], fromList [(5,"aa"), (7,"zz")])
   
   mapEitherWithKey (\_ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])
   == (empty, fromList [(1,"x"), (3,"b"), (5,"a"), (7,"z")])
   

9. mapKeys :: (Key -> Key) -> Word64Map a -> Word64Map a

   ghc	GHC.Data.Word64Map.Lazy

   mapKeys f s is the map obtained by applying f to each key of s. The size of the result may be smaller if f maps two or more distinct keys to the same new key. In this case the value at the greatest of the original keys is retained.

   mapKeys (+ 1) (fromList [(5,"a"), (3,"b")])                        == fromList [(4, "b"), (6, "a")]
   mapKeys (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "c"
   mapKeys (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "c"
   

10. mapKeysMonotonic :: (Key -> Key) -> Word64Map a -> Word64Map a

    ghc	GHC.Data.Word64Map.Lazy

    mapKeysMonotonic f s == mapKeys f s, but works only when f is strictly monotonic. That is, for any values x and y, if x < y then f x < f y. The precondition is not checked. Semi-formally, we have:

    and [x < y ==> f x < f y | x <- ls, y <- ls]
    ==> mapKeysMonotonic f s == mapKeys f s
    where ls = keys s
    

    This means that f maps distinct original keys to distinct resulting keys. This function has slightly better performance than mapKeys.

    mapKeysMonotonic (\ k -> k * 2) (fromList [(5,"a"), (3,"b")]) == fromList [(6, "b"), (10, "a")]
    

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