-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | An implementation of a real-time concurrent queue
--   
--   An implementation of a real-time concurrent queue.
@package stm-queue
@version 0.1.0.0


module Data.Queue

-- | Create a new, empty queue
newQueue :: STM (Queue a)

-- | Peek at the top of the queue, returning the top element.
peek :: Queue a -> STM a

-- | Try to <a>peek</a> for the top item of the queue. This function is
--   offered to easily port from the <a>TQueue</a> offered in the stm
--   package, but is not the intended usage of the library.
tryPeek :: Queue a -> STM (Maybe a)

-- | Enqueue a single item onto the queue.
enqueue :: Queue a -> a -> STM ()

-- | Dequeue a single item onto the queue, <a>retry</a>ing if there is
--   nothing there. This is the motivating use case of this library,
--   allowing a thread to register its interest in the head of a queue and
--   be woken up by the runtime system to read from the top of that queue
--   when an item has been made available.
dequeue :: Queue a -> STM a

-- | Try to <a>dequeue</a> a single item. This function is offered to allow
--   users to easily port from the <a>TQueue</a> offered in the stm
--   package, but is not the intended usage of the library.
tryDequeue :: Queue a -> STM (Maybe a)