unordered-containers-0.2.20: Efficient hashing-based container types

Safe Haskell | None
Language | Haskell2010

Data.HashMap.Internal

Contents

- Construction
- Basic interface
- Combine
  - Union
  - Compose
- Transformations
- Difference and intersection
- Folds
- Filter
- Conversions
  - Lists
  - Internals used by the strict version

Description

# WARNING

This module is considered internal.

The Package Versioning Policy does not apply.

The contents of this module may change in any way whatsoever and without any warning between minor versions of this package.

Authors importing this module are expected to track development closely.

Synopsis

- data HashMap k v
  - = Empty
  - | BitmapIndexed !Bitmap !(Array (HashMap k v))
  - | Leaf !Hash !(Leaf k v)
  - | Full !(Array (HashMap k v))
  - | Collision !Hash !(Array (Leaf k v))
- data Leaf k v = L !k v
- empty :: HashMap k v
- singleton :: Hashable k => k -> v -> HashMap k v
- null :: HashMap k v -> Bool
- size :: HashMap k v -> Int
- member :: (Eq k, Hashable k) => k -> HashMap k a -> Bool
- lookup :: (Eq k, Hashable k) => k -> HashMap k v -> Maybe v
- (!?) :: (Eq k, Hashable k) => HashMap k v -> k -> Maybe v
- findWithDefault :: (Eq k, Hashable k) => v -> k -> HashMap k v -> v
- lookupDefault :: (Eq k, Hashable k) => v -> k -> HashMap k v -> v
- (!) :: (Eq k, Hashable k, HasCallStack) => HashMap k v -> k -> v
- insert :: (Eq k, Hashable k) => k -> v -> HashMap k v -> HashMap k v
- insertWith :: (Eq k, Hashable k) => (v -> v -> v) -> k -> v -> HashMap k v -> HashMap k v
- unsafeInsert :: (Eq k, Hashable k) => k -> v -> HashMap k v -> HashMap k v
- delete :: (Eq k, Hashable k) => k -> HashMap k v -> HashMap k v
- adjust :: (Eq k, Hashable k) => (v -> v) -> k -> HashMap k v -> HashMap k v
- update :: (Eq k, Hashable k) => (a -> Maybe a) -> k -> HashMap k a -> HashMap k a
- alter :: (Eq k, Hashable k) => (Maybe v -> Maybe v) -> k -> HashMap k v -> HashMap k v
- alterF :: (Functor f, Eq k, Hashable k) => (Maybe v -> f (Maybe v)) -> k -> HashMap k v -> f (HashMap k v)
- isSubmapOf :: (Eq k, Hashable k, Eq v) => HashMap k v -> HashMap k v -> Bool
- isSubmapOfBy :: (Eq k, Hashable k) => (v1 -> v2 -> Bool) -> HashMap k v1 -> HashMap k v2 -> Bool
- union :: Eq k => HashMap k v -> HashMap k v -> HashMap k v
- unionWith :: Eq k => (v -> v -> v) -> HashMap k v -> HashMap k v -> HashMap k v
- unionWithKey :: Eq k => (k -> v -> v -> v) -> HashMap k v -> HashMap k v -> HashMap k v
- unions :: Eq k => [HashMap k v] -> HashMap k v
- compose :: (Eq b, Hashable b) => HashMap b c -> HashMap a b -> HashMap a c
- map :: (v1 -> v2) -> HashMap k v1 -> HashMap k v2
- mapWithKey :: (k -> v1 -> v2) -> HashMap k v1 -> HashMap k v2
- traverseWithKey :: Applicative f => (k -> v1 -> f v2) -> HashMap k v1 -> f (HashMap k v2)
- mapKeys :: (Eq k2, Hashable k2) => (k1 -> k2) -> HashMap k1 v -> HashMap k2 v
- difference :: (Eq k, Hashable k) => HashMap k v -> HashMap k w -> HashMap k v
- differenceWith :: (Eq k, Hashable k) => (v -> w -> Maybe v) -> HashMap k v -> HashMap k w -> HashMap k v
- intersection :: Eq k => HashMap k v -> HashMap k w -> HashMap k v
- intersectionWith :: Eq k => (v1 -> v2 -> v3) -> HashMap k v1 -> HashMap k v2 -> HashMap k v3
- intersectionWithKey :: Eq k => (k -> v1 -> v2 -> v3) -> HashMap k v1 -> HashMap k v2 -> HashMap k v3
- intersectionWithKey# :: Eq k => (k -> v1 -> v2 -> (# v3 #)) -> HashMap k v1 -> HashMap k v2 -> HashMap k v3
- foldr' :: (v -> a -> a) -> a -> HashMap k v -> a
- foldl' :: (a -> v -> a) -> a -> HashMap k v -> a
- foldrWithKey' :: (k -> v -> a -> a) -> a -> HashMap k v -> a
- foldlWithKey' :: (a -> k -> v -> a) -> a -> HashMap k v -> a
- foldr :: (v -> a -> a) -> a -> HashMap k v -> a
- foldl :: (a -> v -> a) -> a -> HashMap k v -> a
- foldrWithKey :: (k -> v -> a -> a) -> a -> HashMap k v -> a
- foldlWithKey :: (a -> k -> v -> a) -> a -> HashMap k v -> a
- foldMapWithKey :: Monoid m => (k -> v -> m) -> HashMap k v -> m
- mapMaybe :: (v1 -> Maybe v2) -> HashMap k v1 -> HashMap k v2
- mapMaybeWithKey :: (k -> v1 -> Maybe v2) -> HashMap k v1 -> HashMap k v2
- filter :: (v -> Bool) -> HashMap k v -> HashMap k v
- filterWithKey :: (k -> v -> Bool) -> HashMap k v -> HashMap k v
- keys :: HashMap k v -> [k]
- elems :: HashMap k v -> [v]
- toList :: HashMap k v -> [(k, v)]
- fromList :: (Eq k, Hashable k) => [(k, v)] -> HashMap k v
- fromListWith :: (Eq k, Hashable k) => (v -> v -> v) -> [(k, v)] -> HashMap k v
- fromListWithKey :: (Eq k, Hashable k) => (k -> v -> v -> v) -> [(k, v)] -> HashMap k v
- type Hash = Word
- type Bitmap = Word
- type Shift = Int
- bitmapIndexedOrFull :: Bitmap -> Array (HashMap k v) -> HashMap k v
- collision :: Hash -> Leaf k v -> Leaf k v -> HashMap k v
- hash :: Hashable a => a -> Hash
- mask :: Hash -> Shift -> Bitmap
- index :: Hash -> Shift -> Int
- bitsPerSubkey :: Int
- maxChildren :: Int
- isLeafOrCollision :: HashMap k v -> Bool
- fullBitmap :: Bitmap
- subkeyMask :: Word
- nextShift :: Shift -> Shift
- sparseIndex :: Bitmap -> Bitmap -> Int
- two :: Shift -> Hash -> k -> v -> Hash -> HashMap k v -> ST s (HashMap k v)
- unionArrayBy :: (a -> a -> a) -> Bitmap -> Bitmap -> Array a -> Array a -> Array a
- update32 :: Array e -> Int -> e -> Array e
- update32M :: Array e -> Int -> e -> ST s (Array e)
- update32With' :: Array e -> Int -> (e -> e) -> Array e
- updateOrConcatWithKey :: Eq k => (k -> v -> v -> (# v #)) -> Array (Leaf k v) -> Array (Leaf k v) -> Array (Leaf k v)
- filterMapAux :: (HashMap k v1 -> Maybe (HashMap k v2)) -> (Leaf k v1 -> Maybe (Leaf k v2)) -> HashMap k v1 -> HashMap k v2
- equalKeys :: Eq k => HashMap k v -> HashMap k v' -> Bool
- equalKeys1 :: (k -> k' -> Bool) -> HashMap k v -> HashMap k' v' -> Bool
- lookupRecordCollision :: Eq k => Hash -> k -> HashMap k v -> LookupRes v
- data LookupRes a
  - = Absent
  - | Present a !Int
- lookupResToMaybe :: LookupRes a -> Maybe a
- insert' :: Eq k => Hash -> k -> v -> HashMap k v -> HashMap k v
- delete' :: Eq k => Hash -> k -> HashMap k v -> HashMap k v
- lookup' :: Eq k => Hash -> k -> HashMap k v -> Maybe v
- insertNewKey :: Hash -> k -> v -> HashMap k v -> HashMap k v
- insertKeyExists :: Int -> Hash -> k -> v -> HashMap k v -> HashMap k v
- deleteKeyExists :: Int -> Hash -> k -> HashMap k v -> HashMap k v
- insertModifying :: (Eq k, Hashable k) => v -> (v -> (# v #)) -> k -> HashMap k v -> HashMap k v
- ptrEq :: a -> a -> Bool
- adjust# :: (Eq k, Hashable k) => (v -> (# v #)) -> k -> HashMap k v -> HashMap k v

# Documentation

data HashMap k v #

A map from keys to values. A map cannot contain duplicate keys; each key can map to at most one value.

Constructors

Empty

Invariants:

- `Empty` is not a valid sub-node. It can only appear at the root. (INV1)

BitmapIndexed !Bitmap !(Array (HashMap k v))

Invariants:

- Only the lower `maxChildren` bits of the `Bitmap` may be set. The remaining upper bits must be 0. (INV2)
- The array of a `BitmapIndexed` node stores at least 1 and at most ``maxChildren` - 1` sub-nodes. (INV3)
- The number of sub-nodes is equal to the number of 1-bits in its `Bitmap`. (INV4)
- If a `BitmapIndexed` node has only one sub-node, this sub-node must be a `BitmapIndexed` or a `Full` node. (INV5)

Leaf !Hash !(Leaf k v)

Invariants:

- The location of a `Leaf` or `Collision` node in the tree must be compatible with its `Hash`. (INV6) (TODO: Document this properly (#425))
- The `Hash` of a `Leaf` node must be the `hash` of its key. (INV7)

Full !(Array (HashMap k v))

Invariants:

- The array of a `Full` node stores exactly `maxChildren` sub-nodes. (INV8)

Collision !Hash !(Array (Leaf k v))

Invariants:

- The location of a `Leaf` or `Collision` node in the tree must be compatible with its `Hash`. (INV6) (TODO: Document this properly (#425))
- The array of a `Collision` node must contain at least two sub-nodes. (INV9)
- The `hash` of each key in a `Collision` node must be the one stored in the node. (INV7)
- No two keys stored in a `Collision` can be equal according to their `Eq` instance. (INV10)

#### Instances

Instances details

Bifoldable HashMap # | Since: 0.2.11
Instance details Defined in Data.HashMap.Internal Methods bifold :: Monoid m => HashMap m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> HashMap a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> HashMap a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> HashMap a b -> c #
Eq2 HashMap # |
Instance details Defined in Data.HashMap.Internal Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> HashMap a c -> HashMap b d -> Bool #
Ord2 HashMap # |
Instance details Defined in Data.HashMap.Internal Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> HashMap a c -> HashMap b d -> Ordering #
Show2 HashMap # |
Instance details Defined in Data.HashMap.Internal Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> HashMap a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [HashMap a b] -> ShowS #
NFData2 HashMap # | Since: 0.2.14.0
Instance details Defined in Data.HashMap.Internal Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> HashMap a b -> () #
Hashable2 HashMap # |
Instance details Defined in Data.HashMap.Internal Methods liftHashWithSalt2 :: (Int -> a -> Int) -> (Int -> b -> Int) -> Int -> HashMap a b -> Int #
(Lift k, Lift v) => Lift (HashMap k v :: Type) # | Since: 0.2.17.0
Instance details Defined in Data.HashMap.Internal Methods lift :: Quote m => HashMap k v -> m Exp # liftTyped :: forall (m :: Type -> Type). Quote m => HashMap k v -> Code m (HashMap k v) #
Foldable (HashMap k) # |

Instance details

Defined in Data.HashMap.Internal

Methods

fold :: Monoid m => HashMap k m -> m #

foldMap :: Monoid m => (a -> m) -> HashMap k a -> m #

foldMap' :: Monoid m => (a -> m) -> HashMap k a -> m #

foldr :: (a -> b -> b) -> b -> HashMap k a -> b #

foldr' :: (a -> b -> b) -> b -> HashMap k a -> b #

foldl :: (b -> a -> b) -> b -> HashMap k a -> b #

foldl' :: (b -> a -> b) -> b -> HashMap k a -> b #

foldr1 :: (a -> a -> a) -> HashMap k a -> a #

foldl1 :: (a -> a -> a) -> HashMap k a -> a #

toList :: HashMap k a -> [a] #

null :: HashMap k a -> Bool #

length :: HashMap k a -> Int #

elem :: Eq a => a -> HashMap k a -> Bool #

maximum :: Ord a => HashMap k a -> a #

minimum :: Ord a => HashMap k a -> a #

sum :: Num a => HashMap k a -> a #

product :: Num a => HashMap k a -> a #

Eq k => Eq1 (HashMap k) # |
Instance details Defined in Data.HashMap.Internal Methods liftEq :: (a -> b -> Bool) -> HashMap k a -> HashMap k b -> Bool #
Ord k => Ord1 (HashMap k) # |
Instance details Defined in Data.HashMap.Internal Methods liftCompare :: (a -> b -> Ordering) -> HashMap k a -> HashMap k b -> Ordering #
(Eq k, Hashable k, Read k) => Read1 (HashMap k) # |
Instance details Defined in Data.HashMap.Internal Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (HashMap k a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [HashMap k a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (HashMap k a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [HashMap k a] #
Show k => Show1 (HashMap k) # |
Instance details Defined in Data.HashMap.Internal Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> HashMap k a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [HashMap k a] -> ShowS #
Traversable (HashMap k) # |
Instance details Defined in Data.HashMap.Internal Methods traverse :: Applicative f => (a -> f b) -> HashMap k a -> f (HashMap k b) # sequenceA :: Applicative f => HashMap k (f a) -> f (HashMap k a) # mapM :: Monad m => (a -> m b) -> HashMap k a -> m (HashMap k b) # sequence :: Monad m => HashMap k (m a) -> m (HashMap k a) #
Functor (HashMap k) # |
Instance details Defined in Data.HashMap.Internal Methods fmap :: (a -> b) -> HashMap k a -> HashMap k b # (<$) :: a -> HashMap k b -> HashMap k a #
NFData k => NFData1 (HashMap k) # | Since: 0.2.14.0
Instance details Defined in Data.HashMap.Internal Methods liftRnf :: (a -> ()) -> HashMap k a -> () #
Hashable k => Hashable1 (HashMap k) # |
Instance details Defined in Data.HashMap.Internal Methods liftHashWithSalt :: (Int -> a -> Int) -> Int -> HashMap k a -> Int #
(Data k, Data v, Eq k, Hashable k) => Data (HashMap k v) # |

Instance details

Defined in Data.HashMap.Internal

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> HashMap k v -> c (HashMap k v) #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (HashMap k v) #

toConstr :: HashMap k v -> Constr #

dataTypeOf :: HashMap k v -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (HashMap k v)) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (HashMap k v)) #

gmapT :: (forall b. Data b => b -> b) -> HashMap k v -> HashMap k v #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> HashMap k v -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> HashMap k v -> r #

gmapQ :: (forall d. Data d => d -> u) -> HashMap k v -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> HashMap k v -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) #

(Eq k, Hashable k) => Monoid (HashMap k v) #

`mempty` = `empty`

`mappend` = `union`

If a key occurs in both maps, the mapping from the first will be the mapping in the result.

#### Examples

Expand

    >>> mappend (fromList [(1,'a'),(2,'b')]) (fromList [(2,'c'),(3,'d')])
    fromList [(1,'a'),(2,'b'),(3,'d')]

Instance details Defined in Data.HashMap.Internal Methods mempty :: HashMap k v # mappend :: HashMap k v -> HashMap k v -> HashMap k v # mconcat :: [HashMap k v] -> HashMap k v #

(Eq k, Hashable k) => Semigroup (HashMap k v) #

`<>` = `union`

If a key occurs in both maps, the mapping from the first will be the mapping in the result.

#### Examples

Expand

    >>> fromList [(1,'a'),(2,'b')] <> fromList [(2,'c'),(3,'d')]
    fromList [(1,'a'),(2,'b'),(3,'d')]

Instance details Defined in Data.HashMap.Internal Methods (<>) :: HashMap k v -> HashMap k v -> HashMap k v # sconcat :: NonEmpty (HashMap k v) -> HashMap k v # stimes :: Integral b => b -> HashMap k v -> HashMap k v #
(Eq k, Hashable k) => IsList (HashMap k v) # |

Instance details

Defined in Data.HashMap.Internal

Associated Types

type Item (HashMap k v) |
Instance details Defined in Data.HashMap.Internal type Item (HashMap k v) = (k, v)

Methods

fromList :: [Item (HashMap k v)] -> HashMap k v #

fromListN :: Int -> [Item (HashMap k v)] -> HashMap k v #

toList :: HashMap k v -> [Item (HashMap k v)] #

(Eq k, Hashable k, Read k, Read e) => Read (HashMap k e) # |
Instance details Defined in Data.HashMap.Internal Methods readsPrec :: Int -> ReadS (HashMap k e) # readList :: ReadS [HashMap k e] # readPrec :: ReadPrec (HashMap k e) # readListPrec :: ReadPrec [HashMap k e] #
(Show k, Show v) => Show (HashMap k v) # |
Instance details Defined in Data.HashMap.Internal Methods showsPrec :: Int -> HashMap k v -> ShowS # show :: HashMap k v -> String # showList :: [HashMap k v] -> ShowS #
(NFData k, NFData v) => NFData (HashMap k v) # |
Instance details Defined in Data.HashMap.Internal Methods rnf :: HashMap k v -> () #

(Eq k, Eq v) => Eq (HashMap k v) #

Note that, in the presence of hash collisions, equal `HashMap`s may behave differently, i.e. extensionality may be violated:

    >>> data D = A | B deriving (Eq, Show)
    >>> instance Hashable D where hashWithSalt salt _d = salt

    >>> x = fromList [(A,1), (B,2)]
    >>> y = fromList [(B,2), (A,1)]

    >>> x == y
    True
    >>> toList x
    [(A,1),(B,2)]
    >>> toList y
    [(B,2),(A,1)]

In general, the lack of extensionality can be observed with any function that depends on the key ordering, such as folds and traversals.

Instance details Defined in Data.HashMap.Internal Methods (==) :: HashMap k v -> HashMap k v -> Bool # (/=) :: HashMap k v -> HashMap k v -> Bool #
(Ord k, Ord v) => Ord (HashMap k v) # | The ordering is total and consistent with the `Eq` instance. However, nothing else about the ordering is specified, and it may change from version to version of either this package or of hashable.
Instance details Defined in Data.HashMap.Internal Methods compare :: HashMap k v -> HashMap k v -> Ordering # (<) :: HashMap k v -> HashMap k v -> Bool # (<=) :: HashMap k v -> HashMap k v -> Bool # (>) :: HashMap k v -> HashMap k v -> Bool # (>=) :: HashMap k v -> HashMap k v -> Bool # max :: HashMap k v -> HashMap k v -> HashMap k v # min :: HashMap k v -> HashMap k v -> HashMap k v #
(Hashable k, Hashable v) => Hashable (HashMap k v) # |
Instance details Defined in Data.HashMap.Internal Methods hashWithSalt :: Int -> HashMap k v -> Int # hash :: HashMap k v -> Int #
type Item (HashMap k v) # |
Instance details Defined in Data.HashMap.Internal type Item (HashMap k v) = (k, v)

data Leaf k v #

Constructors

L !k v |

#### Instances

Instances details

NFData2 Leaf # | Since: 0.2.14.0
Instance details Defined in Data.HashMap.Internal Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> Leaf a b -> () #
(Lift k, Lift v) => Lift (Leaf k v :: Type) # | Since: 0.2.17.0
Instance details Defined in Data.HashMap.Internal Methods lift :: Quote m => Leaf k v -> m Exp # liftTyped :: forall (m :: Type -> Type). Quote m => Leaf k v -> Code m (Leaf k v) #
NFData k => NFData1 (Leaf k) # | Since: 0.2.14.0
Instance details Defined in Data.HashMap.Internal Methods liftRnf :: (a -> ()) -> Leaf k a -> () #
(NFData k, NFData v) => NFData (Leaf k v) # |
Instance details Defined in Data.HashMap.Internal Methods rnf :: Leaf k v -> () #
(Eq k, Eq v) => Eq (Leaf k v) # |
Instance details Defined in Data.HashMap.Internal Methods (==) :: Leaf k v -> Leaf k v -> Bool # (/=) :: Leaf k v -> Leaf k v -> Bool #

# Construction

empty :: HashMap k v #

\(O(1)\) Construct an empty map.

singleton :: Hashable k => k -> v -> HashMap k v #

\(O(1)\) Construct a map with a single element.

# Basic interface

null :: HashMap k v -> Bool #

\(O(1)\) Return `True` if this map is empty, `False` otherwise.

size :: HashMap k v -> Int #

\(O(n)\) Return the number of key-value mappings in this map.

member :: (Eq k, Hashable k) => k -> HashMap k a -> Bool #

\(O(\log n)\) Return `True` if the specified key is present in the map, `False` otherwise.

lookup :: (Eq k, Hashable k) => k -> HashMap k v -> Maybe v #

\(O(\log n)\) Return the value to which the specified key is mapped, or `Nothing` if this map contains no mapping for the key.

(!?) :: (Eq k, Hashable k) => HashMap k v -> k -> Maybe v #

\(O(\log n)\) Return the value to which the specified key is mapped, or `Nothing` if this map contains no mapping for the key.

This is a flipped version of `lookup`.

Since: 0.2.11

findWithDefault #

Arguments

:: (Eq k, Hashable k) |
=> v | Default value to return.
-> k |
-> HashMap k v |
-> v |

\(O(\log n)\) Return the value to which the specified key is mapped, or the default value if this map contains no mapping for the key.

Since: 0.2.11

lookupDefault #

Arguments

:: (Eq k, Hashable k) |
=> v | Default value to return.
-> k |
-> HashMap k v |
-> v |

\(O(\log n)\) Return the value to which the specified key is mapped, or the default value if this map contains no mapping for the key.

DEPRECATED: lookupDefault is deprecated as of version 0.2.11, replaced by `findWithDefault`.

(!) :: (Eq k, Hashable k, HasCallStack) => HashMap k v -> k -> v infixl 9 #

\(O(\log n)\) Return the value to which the specified key is mapped. Calls `error` if this map contains no mapping for the key.

insert :: (Eq k, Hashable k) => k -> v -> HashMap k v -> HashMap k v #

\(O(\log n)\) Associate the specified value with the specified key in this map. If this map previously contained a mapping for the key, the old value is replaced.

insertWith :: (Eq k, Hashable k) => (v -> v -> v) -> k -> v -> HashMap k v -> HashMap k v #

\(O(\log n)\) Associate the value with the key in this map. If this map previously contained a mapping for the key, the old value is replaced by the result of applying the given function to the new and old value. Example:

    insertWith f k v map
      where f new old = new + old

unsafeInsert :: (Eq k, Hashable k) => k -> v -> HashMap k v -> HashMap k v #

In-place update version of insert

delete :: (Eq k, Hashable k) => k -> HashMap k v -> HashMap k v #

\(O(\log n)\) Remove the mapping for the specified key from this map if present.

adjust :: (Eq k, Hashable k) => (v -> v) -> k -> HashMap k v -> HashMap k v #

\(O(\log n)\) Adjust the value tied to a given key in this map only if it is present. Otherwise, leave the map alone.

update :: (Eq k, Hashable k) => (a -> Maybe a) -> k -> HashMap k a -> HashMap k a #

\(O(\log n)\) The expression `(`update` f k map)` updates the value `x` at `k` (if it is in the map). If `(f x)` is `Nothing`, the element is deleted. If it is `(`Just` y)`, the key `k` is bound to the new value `y`.

alter :: (Eq k, Hashable k) => (Maybe v -> Maybe v) -> k -> HashMap k v -> HashMap k v #

\(O(\log n)\) The expression `(`alter` f k map)` alters the value `x` at `k`, or absence thereof.

`alter` can be used to insert, delete, or update a value in a map. In short:

    lookup k (alter f k m) = f (lookup k m)

alterF :: (Functor f, Eq k, Hashable k) => (Maybe v -> f (Maybe v)) -> k -> HashMap k v -> f (HashMap k v) #

\(O(\log n)\) The expression `(`alterF` f k map)` alters the value `x` at `k`, or absence thereof.

`alterF` can be used to insert, delete, or update a value in a map.

Note: `alterF` is a flipped version of the `at` combinator from Control.Lens.At.

Since: 0.2.10

isSubmapOf :: (Eq k, Hashable k, Eq v) => HashMap k v -> HashMap k v -> Bool #

\(O(n \log m)\) Inclusion of maps. A map is included in another map if the keys are subsets and the corresponding values are equal:

    isSubmapOf m1 m2 = keys m1 `isSubsetOf` keys m2 &&
                       and [ v1 == v2 | (k1,v1) <- toList m1; let v2 = m2 ! k1 ]

#### Examples

Expand

    >>> fromList [(1,'a')] `isSubmapOf` fromList [(1,'a'),(2,'b')]
    True

    >>> fromList [(1,'a'),(2,'b')] `isSubmapOf` fromList [(1,'a')]
    False

Since: 0.2.12

isSubmapOfBy :: (Eq k, Hashable k) => (v1 -> v2 -> Bool) -> HashMap k v1 -> HashMap k v2 -> Bool #

\(O(n \log m)\) Inclusion of maps with value comparison. A map is included in another map if the keys are subsets and if the comparison function is true for the corresponding values:

    isSubmapOfBy cmpV m1 m2 = keys m1 `isSubsetOf` keys m2 &&
                              and [ v1 `cmpV` v2 | (k1,v1) <- toList m1; let v2 = m2 ! k1 ]

#### Examples

Expand

    >>> isSubmapOfBy (<=) (fromList [(1,'a')]) (fromList [(1,'b'),(2,'c')])
    True

    >>> isSubmapOfBy (<=) (fromList [(1,'b')]) (fromList [(1,'a'),(2,'c')])
    False

Since: 0.2.12

# Combine

## Union

union :: Eq k => HashMap k v -> HashMap k v -> HashMap k v #

\(O(n+m)\) The union of two maps. If a key occurs in both maps, the mapping from the first will be the mapping in the result.

#### Examples

Expand

    >>> union (fromList [(1,'a'),(2,'b')]) (fromList [(2,'c'),(3,'d')])
    fromList [(1,'a'),(2,'b'),(3,'d')]

unionWith :: Eq k => (v -> v -> v) -> HashMap k v -> HashMap k v -> HashMap k v #

\(O(n+m)\) 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 :: Eq k => (k -> v -> v -> v) -> HashMap k v -> HashMap k v -> HashMap k v #

\(O(n+m)\) The union of two maps. If a key occurs in both maps, the provided function (first argument) will be used to compute the result.

unions :: Eq k => [HashMap k v] -> HashMap k v #

Construct a set containing all elements from a list of sets.

## Compose

compose :: (Eq b, Hashable b) => HashMap b c -> HashMap a b -> HashMap a c #

Relate the keys of one map to the values of the other, by using the values of the former as keys for lookups in the latter.

Complexity: \( O (n * \log(m)) \), where \(m\) is the size of the first argument

    >>> compose (fromList [('a', "A"), ('b', "B")]) (fromList [(1,'a'),(2,'b'),(3,'z')])
    fromList [(1,"A"),(2,"B")]

    (compose bc ab !?) = (bc !?) <=< (ab !?)

Since: 0.2.13.0

# Transformations

map :: (v1 -> v2) -> HashMap k v1 -> HashMap k v2 #

\(O(n)\) Transform this map by applying a function to every value.

mapWithKey :: (k -> v1 -> v2) -> HashMap k v1 -> HashMap k v2 #

\(O(n)\) Transform this map by applying a function to every value.

traverseWithKey :: Applicative f => (k -> v1 -> f v2) -> HashMap k v1 -> f (HashMap k v2) #

\(O(n)\) Perform an `Applicative` action for each key-value pair in a `HashMap` and produce a `HashMap` of all the results.

Note: the order in which the actions occur is unspecified. In particular, when the map contains hash collisions, the order in which the actions associated with the keys involved will depend in an unspecified way on their insertion order.

mapKeys :: (Eq k2, Hashable k2) => (k1 -> k2) -> HashMap k1 v -> HashMap k2 v #

\(O(n)\). ``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 there is no guarantee which of the associated values is chosen for the conflicting key.

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

Since: 0.2.14.0

# Difference and intersection

difference :: (Eq k, Hashable k) => HashMap k v -> HashMap k w -> HashMap k v #

\(O(n \log m)\) Difference of two maps. Return elements of the first map not existing in the second.

differenceWith :: (Eq k, Hashable k) => (v -> w -> Maybe v) -> HashMap k v -> HashMap k w -> HashMap k v #

\(O(n \log m)\) Difference with a combining function. When two equal keys are encountered, the combining function is applied to the values of these keys. If it returns `Nothing`, the element is discarded (proper set difference). If it returns (``Just` y`), the element is updated with a new value `y`.

intersection :: Eq k => HashMap k v -> HashMap k w -> HashMap k v #

\(O(n \log m)\) Intersection of two maps. Return elements of the first map for keys existing in the second.

intersectionWith :: Eq k => (v1 -> v2 -> v3) -> HashMap k v1 -> HashMap k v2 -> HashMap k v3 #

\(O(n \log m)\) Intersection of two maps. If a key occurs in both maps the provided function is used to combine the values from the two maps.

intersectionWithKey :: Eq k => (k -> v1 -> v2 -> v3) -> HashMap k v1 -> HashMap k v2 -> HashMap k v3 #

\(O(n \log m)\) Intersection of two maps. If a key occurs in both maps the provided function is used to combine the values from the two maps.

intersectionWithKey# :: Eq k => (k -> v1 -> v2 -> (# v3 #)) -> HashMap k v1 -> HashMap k v2 -> HashMap k v3 #

# Folds

foldr' :: (v -> a -> a) -> a -> HashMap k v -> a #

\(O(n)\) Reduce this map by applying a binary operator to all elements, using the given starting value (typically the right-identity of the operator). Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.

foldl' :: (a -> v -> a) -> a -> HashMap k v -> a #

\(O(n)\) Reduce this map by applying a binary operator to all elements, using the given starting value (typically the left-identity of the operator). Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.

foldrWithKey' :: (k -> v -> a -> a) -> a -> HashMap k v -> a #

\(O(n)\) Reduce this map by applying a binary operator to all elements, using the given starting value (typically the right-identity of the operator). Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.

foldlWithKey' :: (a -> k -> v -> a) -> a -> HashMap k v -> a #

\(O(n)\) Reduce this map by applying a binary operator to all elements, using the given starting value (typically the left-identity of the operator). Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.

foldr :: (v -> a -> a) -> a -> HashMap k v -> a #

\(O(n)\) Reduce this map by applying a binary operator to all elements, using the given starting value (typically the right-identity of the operator).

foldl :: (a -> v -> a) -> a -> HashMap k v -> a #

\(O(n)\) Reduce this map by applying a binary operator to all elements, using the given starting value (typically the left-identity of the operator).

foldrWithKey :: (k -> v -> a -> a) -> a -> HashMap k v -> a #

\(O(n)\) Reduce this map by applying a binary operator to all elements, using the given starting value (typically the right-identity of the operator).

foldlWithKey :: (a -> k -> v -> a) -> a -> HashMap k v -> a #

\(O(n)\) Reduce this map by applying a binary operator to all elements, using the given starting value (typically the left-identity of the operator).

foldMapWithKey :: Monoid m => (k -> v -> m) -> HashMap k v -> m #

\(O(n)\) Reduce the map by applying a function to each element and combining the results with a monoid operation.

# Filter

mapMaybe :: (v1 -> Maybe v2) -> HashMap k v1 -> HashMap k v2 #

\(O(n)\) Transform this map by applying a function to every value and retaining only some of them.

mapMaybeWithKey :: (k -> v1 -> Maybe v2) -> HashMap k v1 -> HashMap k v2 #

\(O(n)\) Transform this map by applying a function to every value and retaining only some of them.

filter :: (v -> Bool) -> HashMap k v -> HashMap k v #

\(O(n)\) Filter this map by retaining only elements which values satisfy a predicate.

filterWithKey :: (k -> v -> Bool) -> HashMap k v -> HashMap k v #

\(O(n)\) Filter this map by retaining only elements satisfying a predicate.

# Conversions

keys :: HashMap k v -> [k] #

\(O(n)\) Return a list of this map's keys. The list is produced lazily.

elems :: HashMap k v -> [v] #

\(O(n)\) Return a list of this map's values. The list is produced lazily.

## Lists

toList :: HashMap k v -> [(k, v)] #

\(O(n)\) Return a list of this map's elements. The list is produced lazily. The order of its elements is unspecified.

fromList :: (Eq k, Hashable k) => [(k, v)] -> HashMap k v #

\(O(n)\) Construct a map with the supplied mappings. If the list contains duplicate mappings, the later mappings take precedence.

fromListWith :: (Eq k, Hashable k) => (v -> v -> v) -> [(k, v)] -> HashMap k v #

\(O(n \log n)\) Construct a map from a list of elements. Uses the provided function `f` to merge duplicate entries with `(f newVal oldVal)`.

### Examples

Given a list `xs`, create a map with the number of occurrences of each element in `xs`:

    let xs = ['a', 'b', 'a']
    in fromListWith (+) [ (x, 1) | x <- xs ]

    = fromList [('a', 2), ('b', 1)]

Given a list of key-value pairs `xs :: [(k, v)]`, group all values by their keys and return a `HashMap k [v]`.

    let xs = [('a', 1), ('b', 2), ('a', 3)]
    in fromListWith (++) [ (k, [v]) | (k, v) <- xs ]

    = fromList [('a', [3, 1]), ('b', [2])]

Note that the lists in the resulting map contain elements in reverse order from their occurrences in the original list.

More generally, duplicate entries are accumulated as follows; this matters when `f` is not commutative or not associative.

    fromListWith f [(k, a), (k, b), (k, c), (k, d)]
    = fromList [(k, f d (f c (f b a)))]

fromListWithKey :: (Eq k, Hashable k) => (k -> v -> v -> v) -> [(k, v)] -> HashMap k v #

\(O(n \log n)\) Construct a map from a list of elements. Uses the provided function to merge duplicate entries.

### Examples

Given a list of key-value pairs where the keys are of different flavours, e.g:

    data Key = Div | Sub

and the values need to be combined differently when there are duplicates, depending on the key:

    combine Div = div
    combine Sub = (-)

then `fromListWithKey` can be used as follows:

    fromListWithKey combine [(Div, 2), (Div, 6), (Sub, 2), (Sub, 3)]
    = fromList [(Div, 3), (Sub, 1)]

More generally, duplicate entries are accumulated as follows;

    fromListWith f [(k, a), (k, b), (k, c), (k, d)]
    = fromList [(k, f k d (f k c (f k b a)))]

Since: 0.2.11

## Internals used by the strict version

type Hash = Word #

This type is used to store the hash of a key, as produced with `hash`.

type Bitmap = Word #

A bitmap as contained by a `BitmapIndexed` node, or a `fullBitmap` corresponding to a `Full` node.

Only the lower `maxChildren` bits are used. The remaining bits must be zeros.

type Shift = Int #

`Shift` values correspond to the level of the tree that we're currently operating at. At the root level the `Shift` is `0`. For the subsequent levels the `Shift` values are `bitsPerSubkey`, `2*`bitsPerSubkey`` etc.

Valid values are non-negative and less than `bitSize (0 :: Word)`.

bitmapIndexedOrFull :: Bitmap -> Array (HashMap k v) -> HashMap k v #

Create a `BitmapIndexed` or `Full` node.

collision :: Hash -> Leaf k v -> Leaf k v -> HashMap k v #

Create a `Collision` value with two `Leaf` values.

hash :: Hashable a => a -> Hash #

Convenience function. Compute a hash value for the given value.

mask :: Hash -> Shift -> Bitmap #

Given a `Hash` and a `Shift` that indicates the level in the tree, compute the bitmap that contains only the `index` of the hash at this level.

The result can be used for constructing one-element `BitmapIndexed` nodes or to check whether a `BitmapIndexed` node may possibly contain the given `Hash`.

    >>> mask 0b0010_0010 0
    0b0100

index :: Hash -> Shift -> Int #

Given a `Hash` and a `Shift` that indicates the level in the tree, compute the index into a `Full` node or into the bitmap of a `BitmapIndexed` node.

    >>> index 0b0010_0010 0
    0b0000_0010

bitsPerSubkey :: Int #

Number of bits that are inspected at each level of the hash tree.

This constant is named t in the original Ideal Hash Trees paper.

maxChildren :: Int #

The size of a `Full` node, i.e. `2 ^ `bitsPerSubkey``.

isLeafOrCollision :: HashMap k v -> Bool #

Helper function to detect `Leaf`s and `Collision`s.

fullBitmap :: Bitmap #

A bitmap with the `maxChildren` least significant bits set, i.e. `0xFF_FF_FF_FF`.

subkeyMask :: Word #

Bit mask with the lowest `bitsPerSubkey` bits set, i.e. `0b11111`.

nextShift :: Shift -> Shift #

Increment a `Shift` for use at the next deeper level.

sparseIndex #

Arguments

:: Bitmap | Bitmap of a `BitmapIndexed` node
-> Bitmap | One-bit `mask` corresponding to the `index` of a hash
-> Int | Index into the array of the `BitmapIndexed` node

This array index is computed by counting the number of 1-bits below the `index` represented by the mask.

    >>> sparseIndex 0b0110_0110 0b0010_0000
    2

two :: Shift -> Hash -> k -> v -> Hash -> HashMap k v -> ST s (HashMap k v) #

Create a map from two key-value pairs which hashes don't collide. To enhance sharing, the second key-value pair is represented by the hash of its key and a singleton HashMap pairing its key with its value.

Note: to avoid silly thunks, this function must be strict in the key. See issue #232. We don't need to force the HashMap argument because it's already in WHNF (having just been matched) and we just put it directly in an array.

unionArrayBy :: (a -> a -> a) -> Bitmap -> Bitmap -> Array a -> Array a -> Array a #

Strict in the result of `f`.

update32 :: Array e -> Int -> e -> Array e #

\(O(n)\) Update the element at the given position in this array.

update32M :: Array e -> Int -> e -> ST s (Array e) #

\(O(n)\) Update the element at the given position in this array.

update32With' :: Array e -> Int -> (e -> e) -> Array e #

\(O(n)\) Update the element at the given position in this array, by applying a function to it.

updateOrConcatWithKey :: Eq k => (k -> v -> v -> (# v #)) -> Array (Leaf k v) -> Array (Leaf k v) -> Array (Leaf k v) #

filterMapAux :: (HashMap k v1 -> Maybe (HashMap k v2)) -> (Leaf k v1 -> Maybe (Leaf k v2)) -> HashMap k v1 -> HashMap k v2 #

Common implementation for `filterWithKey` and `mapMaybeWithKey`, allowing the former to former to reuse terms.

equalKeys :: Eq k => HashMap k v -> HashMap k v' -> Bool #

equalKeys1 :: (k -> k' -> Bool) -> HashMap k v -> HashMap k' v' -> Bool #

lookupRecordCollision :: Eq k => Hash -> k -> HashMap k v -> LookupRes v #

data LookupRes a #

Constructors

Absent |
Present a !Int |

lookupResToMaybe :: LookupRes a -> Maybe a #

insert' :: Eq k => Hash -> k -> v -> HashMap k v -> HashMap k v #

delete' :: Eq k => Hash -> k -> HashMap k v -> HashMap k v #

lookup' :: Eq k => Hash -> k -> HashMap k v -> Maybe v #

lookup' is a version of lookup that takes the hash separately. It is used to implement alterF.

insertNewKey :: Hash -> k -> v -> HashMap k v -> HashMap k v #

insertKeyExists :: Int -> Hash -> k -> v -> HashMap k v -> HashMap k v #

deleteKeyExists :: Int -> Hash -> k -> HashMap k v -> HashMap k v #

Delete optimized for the case when we know the key is in the map.

It is only valid to call this when the key exists in the map and you know the hash collision position if there was one. This information can be obtained from `lookupRecordCollision`. If there is no collision, pass (-1) as collPos.

insertModifying :: (Eq k, Hashable k) => v -> (v -> (# v #)) -> k -> HashMap k v -> HashMap k v #

`insertModifying` is a lot like insertWith; we use it to implement alterF. It takes a value to insert when the key is absent and a function to apply to calculate a new value when the key is present. Thanks to the unboxed unary tuple, we avoid introducing any unnecessary thunks in the tree.

ptrEq :: a -> a -> Bool #

Check if two the two arguments are the same value. N.B. This function might give false negatives (due to GC moving objects.)

adjust# :: (Eq k, Hashable k) => (v -> (# v #)) -> k -> HashMap k v -> HashMap k v #

Much like `adjust`, but not inherently leaky.