Moduleunordered-containers-0.2.21Haskell2010

Data.HashMap.Internal

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.

6 types
89 values

Packageunordered-containers-0.2.21
Exports95
LanguageHaskell2010
LicenceBSD-3-Clause
SourceInternal.hs

datadata 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)

Instances27Bifoldable, Eq2, Ord2, Show2, NFData2, Hashable2, …

Bifoldable HashMapDefined in unordered-containers-0.2.21 · Data.HashMap.Internal
Eq2 HashMapDefined in unordered-containers-0.2.21 · Data.HashMap.Internal
Ord2 HashMapDefined in unordered-containers-0.2.21 · Data.HashMap.Internal
Show2 HashMapDefined in unordered-containers-0.2.21 · Data.HashMap.Internal
NFData2 HashMapDefined in unordered-containers-0.2.21 · Data.HashMap.Internal
Hashable2 HashMapDefined in unordered-containers-0.2.21 · Data.HashMap.Internal
(Lift k, Lift v) => Lift (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Functor (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Foldable (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Traversable (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Eq k => Eq1 (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Ord k => Ord1 (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
(Hashable k, Read k) => Read1 (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Show k => Show1 (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
NFData k => NFData1 (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Hashable k => Hashable1 (HashMap k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Hashable k => IsList (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
(Eq k, Eq v) => Eq (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Note that, in the presence of hash collisions, equal HashMaps may behave differently, i.e. extensionality may be violated:
Example2 expressions
```
>>> data D = A | B deriving (Eq, Show)>>> instance Hashable D where hashWithSalt salt _d = salt
```
Example2 expressions
```
>>> x = fromList [(A,1), (B,2)]>>> y = fromList [(B,2), (A,1)]
```
Example3 expressions
```
>>> x == yTrue>>> 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.
(Data k, Data v, Hashable k) => Data (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
(Ord k, Ord v) => Ord (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
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.
(Hashable k, Read k, Read e) => Read (HashMap k e)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
(Show k, Show v) => Show (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
Hashable k => Semigroup (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
<> = union
If a key occurs in both maps, the mapping from the first will be the mapping in the result.
Examples
Example1 expression
```
>>> fromList [(1,'a'),(2,'b')] <> fromList [(2,'c'),(3,'d')]fromList [(1,'a'),(2,'b'),(3,'d')]
```
Hashable k => Monoid (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
mempty = empty
mappend = union
If a key occurs in both maps, the mapping from the first will be the mapping in the result.
Examples
Example1 expression
```
>>> mappend (fromList [(1,'a'),(2,'b')]) (fromList [(2,'c'),(3,'d')])fromList [(1,'a'),(2,'b'),(3,'d')]
```
(NFData k, NFData v) => NFData (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
(Hashable k, Hashable v) => Hashable (HashMap k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
type Item (HashMap k v) = (k, v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal

datadata Leaf k v

Constructors

L !k v

Instances5NFData2, Lift, NFData1, Eq, NFData

NFData2 LeafDefined in unordered-containers-0.2.21 · Data.HashMap.Internal
(Lift k, Lift v) => Lift (Leaf k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
NFData k => NFData1 (Leaf k)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
(Eq k, Eq v) => Eq (Leaf k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal
(NFData k, NFData v) => NFData (Leaf k v)Defined in unordered-containers-0.2.21 · Data.HashMap.Internal

Construction

2 declarations

valueempty :: HashMap k v

O(1) Construct an empty map.

valuesingleton :: Hashable k => k -> v -> HashMap k v

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

Basic interface

19 declarations

valuenull :: HashMap k v -> Bool

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

valuesize :: HashMap k v -> Int

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

valuemember :: Hashable k => k -> HashMap k a -> Bool

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

valuelookup :: 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.

value(!?) :: 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.

valuefindWithDefault

:: 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.

valuelookupDefault

:: 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.

value(!) :: (Hashable k, HasCallStack) => HashMap k v -> k -> v

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

valuelookupKey :: Hashable k => k -> HashMap k v -> Maybe k

O(\log n) For a given key, return the equal key stored in the map, if present, otherwise return Nothing.

This function can be used for interning, i.e. to reduce memory usage.

valueinsert :: 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.

valueinsertWith

:: 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

valueunsafeInsert :: Hashable k => k -> v -> HashMap k v -> HashMap k v

In-place update version of insert

valuedelete :: Hashable k => k -> HashMap k v -> HashMap k v

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

valueadjust :: 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.

valueupdate :: 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.

valuealter

:: 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)

valuealterF

:: (Functor f, 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.

valueisSubmapOf :: (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

Example1 expression

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

Example1 expression

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

valueisSubmapOfBy

:: 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

Example1 expression

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

Example1 expression

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

Combine

0 declarations

Union

valueunion :: 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

Example1 expression

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

valueunionWith

:: 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.

valueunionWithKey

:: 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.

valueunions :: Eq k => [HashMap k v] -> HashMap k v

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

Compose

valuecompose :: Hashable b => HashMap b c -> HashMap a b -> HashMap a c

Given maps bc and ab, relate the keys of ab to the values of bc, by using the values of ab as keys for lookups in bc.

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

Example1 expression

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

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

Transformations

4 declarations

valuemap :: (v1 -> v2) -> HashMap k v1 -> HashMap k v2

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

valuemapWithKey :: (k -> v1 -> v2) -> HashMap k v1 -> HashMap k v2

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

valuetraverseWithKey

:: 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.

valuemapKeys :: 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.

Example3 expressions

>>> 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")]

Difference and intersection

8 declarations

valuedifference :: 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.

valuedifferenceWith

:: 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.

valuedifferenceWithKey

:: Eq k
=> k -> v -> w -> Maybe v
-> HashMap k v
-> HashMap k w
-> HashMap k v

valueintersection :: 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.

valueintersectionWith

:: 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.

valueintersectionWithKey

:: 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.

valueintersectionWithKey#

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

valuedisjoint :: Eq k => HashMap k a -> HashMap k b -> Bool

O(n \log m) Check whether the key sets of two maps are disjoint (i.e., their intersection is empty).

xs `disjoint` ys = null (xs `intersection` ys)

Folds

9 declarations

valuefoldr' :: (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.

valuefoldl' :: (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.

valuefoldrWithKey' :: (k -> v -> a -> a) -> a -> HashMap k v -> a

valuefoldlWithKey' :: (a -> k -> v -> a) -> a -> HashMap k v -> a

valuefoldr :: (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).

valuefoldl :: (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).

valuefoldrWithKey :: (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).

valuefoldlWithKey :: (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).

valuefoldMapWithKey :: 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

4 declarations

valuemapMaybe :: (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.

valuemapMaybeWithKey :: (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.

valuefilter :: (v -> Bool) -> HashMap k v -> HashMap k v

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

valuefilterWithKey :: (k -> v -> Bool) -> HashMap k v -> HashMap k v

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

Conversions

2 declarations

valuekeys :: HashMap k v -> [k]

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

valueelems :: HashMap k v -> [v]

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

Lists

valuetoList :: 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, and it may change from version to version of either this package or of hashable.

valuefromList :: Hashable k => [(k, v)] -> HashMap k v

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

valuefromListWith :: 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)))]

valuefromListWithKey

:: 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)))]

Internals used by the strict version

typetype Hash = Word

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

typetype 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.

typetype Shift = Int

A Shift value is the offset of the subkey in the hash and corresponds 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).

valuebitmapIndexedOrFull :: Bitmap -> Array (HashMap k v) -> HashMap k v

Create a BitmapIndexed or Full node.

valuecollision :: Hash -> Leaf k v -> Leaf k v -> HashMap k v

Create a Collision value with two Leaf values.

valuehash :: Hashable a => a -> Hash

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

valuemask :: 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.

Example1 expression

>>> mask 0b0010_0010 00b0100

valueindex :: 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.

Example1 expression

>>> index 0b0010_0010 00b0000_0010

valuebitsPerSubkey :: 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.

Note that this constant is platform-dependent. On 32-bit platforms we use '4', because bitmaps using '2^5' bits turned out to be prone to integer overflow bugs. See #491 for instance.

valuemaxChildren :: Int

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

valueisLeafOrCollision :: HashMap k v -> Bool

Helper function to detect Leafs and Collisions.

valuefullBitmap :: Bitmap

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

valuesubkeyMask :: Word

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

valuenextShift :: Shift -> Shift

Increment a Shift for use at the next deeper level.

valuesparseIndex

:: 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.

Example1 expression

>>> sparseIndex 0b0110_0110 0b0010_00002

valuetwo :: 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.

valueunionArrayBy

:: a -> a -> a
-> Bitmap
-> Bitmap
-> Array a
-> Array a
-> Array a

Strict in the result of f.

valueupdateFullArray :: Array e -> Int -> e -> Array e

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

valueupdateFullArrayM :: Array e -> Int -> e -> ST s (Array e)

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

valueupdateFullArrayWith' :: 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.

valueupdateOrConcatWithKey

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

valuefilterMapAux

:: 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.

valueequalKeys :: Eq k => HashMap k v -> HashMap k v' -> Bool

Same as equal1 but doesn't compare the values.

valueequalKeys1 :: (k -> k' -> Bool) -> HashMap k v -> HashMap k' v' -> Bool

Same as equal2 but doesn't compare the values.

valuelookupRecordCollision :: Eq k => Hash -> k -> HashMap k v -> LookupRes v

Internal helper for lookup. This version takes the precomputed hash so that functions that make multiple calls to lookup and related functions (insert, delete) only need to calculate the hash once.

It is used by alterF so that hash computation and key comparison only needs to be performed once. With this information you can use the more optimized versions of insert (insertNewKey, insertKeyExists) and delete (deleteKeyExists)

Outcomes: Key not in map => Absent Key in map, no collision => Present v (-1) Key in map, collision => Present v position

datadata LookupRes a

The result of a lookup, keeping track of if a hash collision occurred. If a collision did not occur then it will have the Int value (-1).

Constructors

Absent
Present a !Int

valuelookupResToMaybe :: LookupRes a -> Maybe a

valueinsert' :: Eq k => Hash -> k -> v -> HashMap k v -> HashMap k v

valuedelete' :: Eq k => Hash -> k -> HashMap k v -> HashMap k v

valuelookup' :: 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.

valueinsertNewKey :: Hash -> k -> v -> HashMap k v -> HashMap k v

Insert optimized for the case when we know the key is not in the map.

It is only valid to call this when the key does not exist in the map.

We can skip: - the key equality check on a Leaf - check for its existence in the array for a hash collision

valueinsertKeyExists :: Int -> Hash -> k -> v -> HashMap k v -> HashMap k v

Insert 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 (first argument).

valuedeleteKeyExists :: Int -> Hash -> k -> HashMap k v -> HashMap k v

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

valueinsertModifying

:: 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.

valueptrEq :: 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.)

valueadjust# :: Hashable k => (v -> (# v #)) -> k -> HashMap k v -> HashMap k v

Much like adjust, but not inherently leaky.