StmContainers.Bimap

Documentation

data Bimap leftKey rightKey

Bidirectional map. Essentially, a bijection between subsets of its two argument types.

For one value of the left-hand type this map contains one value of the right-hand type and vice versa.

new :: STM (Bimap leftKey rightKey)

Construct a new bimap.

newIO :: IO (Bimap leftKey rightKey)

Construct a new bimap in IO.

This is useful for creating it on a top-level using unsafePerformIO, because using atomically inside unsafePerformIO isn't possible.

null :: Bimap leftKey rightKey -> STM Bool

Check on being empty.

size :: Bimap leftKey rightKey -> STM Int

Get the number of elements.

focusLeft :: (Hashable leftKey, Hashable rightKey) => Focus rightKey STM result -> leftKey -> Bimap leftKey rightKey -> STM result

Focus on a right value by the left value.

This function allows to perform composite operations in a single access to a map item. E.g., you can look up an item and delete it at the same time, or update it and return the new value.

focusRight :: (Hashable leftKey, Hashable rightKey) => Focus leftKey STM result -> rightKey -> Bimap leftKey rightKey -> STM result

Focus on a left value by the right value.

This function allows to perform composite operations in a single access to a map item. E.g., you can look up an item and delete it at the same time, or update it and return the new value.

lookupLeft :: Hashable leftKey => leftKey -> Bimap leftKey rightKey -> STM (Maybe rightKey)

Look up a right value by the left value.

lookupRight :: Hashable rightKey => rightKey -> Bimap leftKey rightKey -> STM (Maybe leftKey)

Look up a left value by the right value.

insertLeft :: (Hashable leftKey, Hashable rightKey) => rightKey -> leftKey -> Bimap leftKey rightKey -> STM ()

Insert the association by the left value.

insertRight :: (Hashable leftKey, Hashable rightKey) => leftKey -> rightKey -> Bimap leftKey rightKey -> STM ()

Insert the association by the right value.

deleteLeft :: (Hashable leftKey, Hashable rightKey) => leftKey -> Bimap leftKey rightKey -> STM ()

Delete the association by the left value.

deleteRight :: (Hashable leftKey, Hashable rightKey) => rightKey -> Bimap leftKey rightKey -> STM ()

Delete the association by the right value.

reset :: Bimap leftKey rightKey -> STM ()

Delete all the associations.

unfoldlM :: Bimap leftKey rightKey -> UnfoldlM STM (leftKey, rightKey)

Stream associations actively.

Amongst other features this function provides an interface to folding.

listT :: Bimap key value -> ListT STM (key, value)

Stream the associations passively.