Data.IOHashMap.STM

Documentation

data IOHashMap k v

newIOHashMap :: HashMap k v -> STM (IOHashMap k v)

readIOHashMap :: (HashMap k v -> a) -> IOHashMap k v -> STM a

modifyIOHashMap :: (HashMap k v -> HashMap k v) -> IOHashMap k v -> STM ()

empty :: STM (IOHashMap k v)

O(1) Construct an empty map.

singleton :: Hashable k => k -> v -> STM (IOHashMap k v)

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

null :: IOHashMap k v -> STM Bool

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

size :: IOHashMap k v -> STM Int

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

member :: (Eq k, Hashable k) => k -> IOHashMap k a -> STM Bool

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

lookup :: (Eq k, Hashable k) => k -> IOHashMap k v -> STM (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) => IOHashMap k v -> k -> STM (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

-> IOHashMap k v

-> STM 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

(!) :: (Eq k, Hashable k) => IOHashMap k v -> k -> STM 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 -> IOHashMap k v -> STM ()

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 -> IOHashMap k v -> STM ()

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

delete :: (Eq k, Hashable k) => k -> IOHashMap k v -> STM ()

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

adjust :: (Eq k, Hashable k) => (v -> v) -> k -> IOHashMap k v -> STM ()

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 -> IOHashMap k a -> STM ()

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 -> IOHashMap k v -> STM ()

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)

foldMapWithKey :: Monoid m => (k -> v -> m) -> IOHashMap k v -> STM m

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

foldr :: (v -> a -> a) -> a -> IOHashMap k v -> STM 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 -> IOHashMap k v -> STM 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).

foldr' :: (v -> a -> a) -> a -> IOHashMap k v -> STM 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 -> IOHashMap k v -> STM 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 -> IOHashMap k v -> STM 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 -> IOHashMap k v -> STM 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 -> IOHashMap k v -> STM 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 -> IOHashMap k v -> STM 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).

keys :: IOHashMap k v -> STM [k]

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

elems :: IOHashMap k v -> STM [v]

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

toList :: IOHashMap k v -> STM [(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)] -> STM (IOHashMap k v)

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