/Haskell 8


Copyright (c) David Feuer 2016
License BSD-style
Maintainer [email protected]
Portability portable
Safe Haskell Safe
Language Haskell98



This module is considered internal.

The Package Versioning Policy does not apply.

The contents of this module may change in any way whatsoever and without any warning between minor versions of this package.

Authors importing this module are expected to track development closely.


An extremely light-weight, fast, and limited representation of a string of up to (2*WORDSIZE - 2) bits. In fact, there are two representations, misleadingly named bit queue builder and bit queue. The builder supports only emptyQB, creating an empty builder, and snocQB, enqueueing a bit. The bit queue builder is then turned into a bit queue using buildQ, after which bits can be removed one by one using unconsQ. If the size limit is exceeded, further operations will silently produce nonsense.

data BitQueue Source

Instances details
Show BitQueue
Instance details

Defined in Utils.Containers.Internal.BitQueue

data BitQueueB Source

Instances details
Show BitQueueB
Instance details

Defined in Utils.Containers.Internal.BitQueue

emptyQB :: BitQueueB Source

Create an empty bit queue builder. This is represented as a single guard bit in the most significant position.

snocQB :: BitQueueB -> Bool -> BitQueueB Source

Enqueue a bit. This works by shifting the queue right one bit, then setting the most significant bit as requested.

buildQ :: BitQueueB -> BitQueue Source

Convert a bit queue builder to a bit queue. This shifts in a new guard bit on the left, and shifts right until the old guard bit falls off.

unconsQ :: BitQueue -> Maybe (Bool, BitQueue) Source

Dequeue an element, or discover the queue is empty.

toListQ :: BitQueue -> [Bool] Source

Convert a bit queue to a list of bits by unconsing. This is used to test that the queue functions properly.

© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).