unionWithKey

unionWithKey :: (Key -> a -> a -> a) -> IntMap a -> IntMap a -> IntMap a
containers Data.IntMap.Internal Data.IntMap.Lazy Data.IntMap.Strict Data.IntMap.Strict.Internal
The union with a combining function. 
let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value
unionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "5:a|A"), (7, "C")]
Also see the performance note on fromListWith.
unionWithKey :: Ord k => (k -> a -> a -> a) -> Map k a -> Map k a -> Map k a
containers Data.Map.Internal Data.Map.Lazy Data.Map.Strict Data.Map.Strict.Internal
Union with a combining function. 
let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value
unionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "5:a|A"), (7, "C")]
Also see the performance note on fromListWith.
unionWithKey :: (Key -> v -> v -> v) -> KeyMap v -> KeyMap v -> KeyMap v
aeson Data.Aeson.KeyMap
The union with a combining function.
unionWithKey :: Eq k => (k -> v -> v -> v) -> HashMap k v -> HashMap k v -> HashMap k v
unordered-containers Data.HashMap.Internal Data.HashMap.Internal.Strict Data.HashMap.Lazy Data.HashMap.Strict
The union of two maps. If a key occurs in both maps, the provided function (first argument) will be used to compute the result.
unionWithKey :: (Key -> a -> a -> a) -> Word64Map a -> Word64Map a -> Word64Map a
ghc GHC.Data.Word64Map.Internal GHC.Data.Word64Map.Lazy GHC.Data.Word64Map.Strict GHC.Data.Word64Map.Strict.Internal, ghc-lib-parser GHC.Data.Word64Map.Internal GHC.Data.Word64Map.Lazy GHC.Data.Word64Map.Strict GHC.Data.Word64Map.Strict.Internal
The union with a combining function. 
let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value
unionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "5:a|A"), (7, "C")]
unionWithKey :: (Key -> a -> a -> a) -> CharMap a -> CharMap a -> CharMap a
regex-tdfa Data.IntMap.CharMap2
unionWithKey :: Enum key => (key -> a -> a -> a) -> EnumMap key a -> EnumMap key a -> EnumMap key a
regex-tdfa Data.IntMap.EnumMap2
unionWithKey :: (Eq k, Hashable k) => (k -> v -> v -> v) -> HashMap k v -> HashMap k v -> HashMap k v
rio RIO.HashMap
The union of two maps. If a key occurs in both maps, the provided function (first argument) will be used to compute the result.
unionWithKey :: Ord k => (k -> a -> a -> a) -> Map k a -> Map k a -> Map k a
rio RIO.Map
O(m*log(n/m + 1)), m <= n. Union with a combining function. 
let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value
unionWithKey f (fromList [(5, "a"), (3, "b")]) (fromList [(5, "A"), (7, "C")]) == fromList [(3, "b"), (5, "5:a|A"), (7, "C")]
unionWithKey :: IsMap map => (ContainerKey map -> MapValue map -> MapValue map -> MapValue map) -> map -> map -> map
mono-traversable Data.Containers
unionWithKey :: GCompare k => (forall v . k v -> f v -> f v -> f v) -> DMap k f -> DMap k f -> DMap k f
dependent-map Data.Dependent.Map
O(n+m). Union with a combining function.
unionWithKey :: (Eq k, Hashable k) => (k -> v -> v -> v) -> InsOrdHashMap k v -> InsOrdHashMap k v -> InsOrdHashMap k v
insert-ordered-containers Data.HashMap.Strict.InsOrd
unionWithKey :: (Fin n -> a -> a -> a) -> FinMap n a -> FinMap n a -> FinMap n a
parameterized-utils Data.Parameterized.FinMap.Safe Data.Parameterized.FinMap.Unsafe
O(n+m).
unionWithKey :: forall a . (Int -> a -> a -> a) -> MonoidalIntMap a -> MonoidalIntMap a -> MonoidalIntMap a
monoidal-containers Data.IntMap.Monoidal Data.IntMap.Monoidal.Strict
unionWithKey :: forall k a . Ord k => (k -> a -> a -> a) -> MonoidalMap k a -> MonoidalMap k a -> MonoidalMap k a
monoidal-containers Data.Map.Monoidal Data.Map.Monoidal.Strict
unionWithKey :: Ord k => (k -> v -> v -> v) -> OMap k v -> OMap k v -> OMap k v
th-desugar Language.Haskell.TH.Desugar.OMap Language.Haskell.TH.Desugar.OMap.Strict
unionWithKey :: Ord k => (k -> a -> a -> a) -> Map k a -> Map k a -> Map k a
hashmap Data.HashMap
The union with a combining function.
unionWithKey :: Enum k => (k -> a -> a -> a) -> EnumMap k a -> EnumMap k a -> EnumMap k a
enummapset Data.EnumMap.Lazy Data.EnumMap.Strict
unionWithKey :: (Key -> a -> a -> a) -> NEIntMap a -> NEIntMap a -> NEIntMap a
nonempty-containers Data.IntMap.NonEmpty
O(m*log(n/m + 1)), m <= n. Union with a combining function, given the matching key. 
let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value
unionWithKey f (fromList ((5, "a") :| [(3, "b")])) (fromList ((5, "A") :| [(7, "C")])) == fromList ((3, "b") :| [(5, "5:a|A"), (7, "C")])
unionWithKey :: Ord k => (k -> a -> a -> a) -> NEMap k a -> NEMap k a -> NEMap k a
nonempty-containers Data.Map.NonEmpty
O(m*log(n/m + 1)), m <= n. Union with a combining function, given the matching key. 
let f key left_value right_value = (show key) ++ ":" ++ left_value ++ "|" ++ right_value
unionWithKey f (fromList ((5, "a") :| [(3, "b")])) (fromList ((5, "A") :| [(7, "C")])) == fromList ((3, "b") :| [(5, "5:a|A"), (7, "C")])
unionWithKey :: (Interval k e, Ord k) => (k -> a -> a -> a) -> IntervalMap k a -> IntervalMap k a -> IntervalMap k a
IntervalMap Data.IntervalMap.Generic.Lazy Data.IntervalMap.Generic.Strict Data.IntervalMap.Lazy Data.IntervalMap.Strict
O(n+m). Union with a combining function.
unionWithKey :: (Word -> a -> a -> a) -> Patricia a -> Patricia a -> Patricia a
radix-tree Data.Patricia.Word.Lazy
Union of two trees with a combining function.
unionWithKey :: (Build1 -> a -> a -> a) -> Radix1Tree a -> Radix1Tree a -> Radix1Tree a
radix-tree Data.Radix1Tree.Word8.Lazy
Union of two trees with a combining function.
unionWithKey :: (Build -> a -> a -> a) -> RadixTree a -> RadixTree a -> RadixTree a
radix-tree Data.RadixTree.Word8.Lazy
Union of two trees with a combining function.
unionWithKey :: (MVector ks k, MVector vs v, PrimMonad m, Hashable k, Eq k) => (k -> v -> v -> v) -> Dictionary (PrimState m) ks k vs v -> Dictionary (PrimState m) ks k vs v -> m (Dictionary (PrimState m) ks k vs v)
vector-hashtables Data.Vector.Hashtables
O(min n m) in the best case, O(min n m * max n m) in the worst case. The union of two maps. If a key occurs in both maps, the provided function (first argument) will be used to compute the result.