Data.Persistent.Queue.Text

This module implements a persistent, transactional collection with Queue interface as well as indexed access by key

use this version if you store in the queue different versions of largue structures, for example, documents and define a Data.RefSerialize instance. If not, use Data.Persistent.Queue.Binary Instead.

Here QueueConstraints w r a means Data.RefSerlialize.Serialize a

Documentation

type RefQueue a = DBRef (Queue a)

a queue reference

getQRef :: (Typeable a, QueueConstraints w r a) => String -> RefQueue a

get the reference to new or existing queue trough its name

pop

Arguments

:: (Typeable a, QueueConstraints w r a)

=> RefQueue a

Queue name

-> IO a

the returned elems

read the first element in the queue and delete it (pop)

popSTM :: (Typeable a, QueueConstraints w r a) => RefQueue a -> STM a

version in the STM monad

pick

Arguments

:: (Typeable a, QueueConstraints w r a)

=> RefQueue a

Queue name

-> IO a

the returned elems

flush :: (Typeable a, QueueConstraints w r a) => RefQueue a -> IO ()

empty the queue (factually, it is deleted)

flushSTM :: (Typeable a, QueueConstraints w r a) => RefQueue a -> STM ()

version in the STM monad

pickAll :: (Typeable a, QueueConstraints w r a) => RefQueue a -> IO [a]

return the list of all elements in the queue. The queue remains unchanged

pickAllSTM :: (Typeable a, QueueConstraints w r a) => RefQueue a -> STM [a]

version in the STM monad

push :: (Typeable a, QueueConstraints w r a) => RefQueue a -> a -> IO ()

push an element in the queue

pushSTM :: (Typeable a, QueueConstraints w r a) => RefQueue a -> a -> STM ()

version in the STM monad

pickElem :: (Indexable a, Typeable a, QueueConstraints w r a) => RefQueue a -> String -> IO (Maybe a)

return the first element in the queue that has the given key

pickElemSTM :: (Indexable a, Typeable a, QueueConstraints w r a) => RefQueue a -> String -> STM (Maybe a)

version in the STM monad

readAll :: (Typeable a, QueueConstraints w r a) => RefQueue a -> IO [a]

return the list of all elements in the queue and empty it

readAllSTM :: (Typeable a, QueueConstraints w r a) => RefQueue a -> STM [a]

a version in the STM monad

deleteElem :: (Indexable a, Typeable a, QueueConstraints w r a) => RefQueue a -> a -> IO ()

delete all the elements of the queue that has the key of the parameter passed

deleteElemSTM :: (Typeable a, Indexable a, QueueConstraints w r a) => RefQueue a -> a -> STM ()

verison in the STM monad

unreadSTM :: (Typeable a, QueueConstraints w r a) => RefQueue a -> a -> STM ()

isEmpty :: (Typeable a, QueueConstraints w r a) => RefQueue a -> IO Bool

check if the queue is empty

isEmptySTM :: (Typeable a, QueueConstraints w r a) => RefQueue a -> STM Bool