Copyright	(c) Naoto Shimazaki 2018-2020
License	MIT (see the file LICENSE)
Maintainer	https://github.com/nshimaza
Stability	experimental
Safe Haskell	Safe
Language	Haskell2010

Data.DelayedQueue

Description

Queue with delay before elements become available to dequeue.

DelayedQueue is a FIFO but it does NOT make element available to pop immediately after the element was pushed. DelayedQueue looks like empty until its delay-buffer is filled up by pushed elements. When a value is pushed to a DelayedQueue where delay-buffer of the queue is already full-filled, the oldest element becomes available to dequeue.

Entire elements within DelayedQueue are always inlined in enqueued order. Only older elements overflowed from delay-buffer are available to dequeue. If delay-buffer is not yet filled, no element is available to dequeue. Once delay-buffer is filled, delay-buffer always keeps given number of newest elements.

Synopsis

data DelayedQueue a
newEmptyDelayedQueue :: Int -> DelayedQueue a
push :: a -> DelayedQueue a -> DelayedQueue a
pop :: DelayedQueue a -> Maybe (a, DelayedQueue a)

Documentation

data DelayedQueue a Source #

Queue with delay before elements become available to dequeue.

Instances

Eq a => Eq (DelayedQueue a) Source #
Instance details Defined in Data.DelayedQueue Methods (==) :: DelayedQueue a -> DelayedQueue a -> Bool # (/=) :: DelayedQueue a -> DelayedQueue a -> Bool #
Show a => Show (DelayedQueue a) Source #
Instance details Defined in Data.DelayedQueue Methods showsPrec :: Int -> DelayedQueue a -> ShowS # show :: DelayedQueue a -> String # showList :: [DelayedQueue a] -> ShowS #

newEmptyDelayedQueue Source #

Arguments

:: Int	Delay of the queue in number of element.
-> DelayedQueue a	Created queue.

Create a new DelayedQueue with given delay.

push Source #

Arguments

:: a	value to be queued.
-> DelayedQueue a	queue where the value to be queued.
-> DelayedQueue a	new queue where the value is pushed.

Enqueue a value to a DelayedQueue.

pop Source #

Arguments

:: DelayedQueue a	`DelayedQueue` from which a value to be pulled.
-> Maybe (a, DelayedQueue a)	Nothing if there is no available element. Returns pulled value and `DelayedQueue` with the value removed wrapped in Just.

Dequeue a value from a DelayedQueue.