Parsley.Internal.Common.RewindQueue.Impl

Implementation of a FIFO queue structure, with amortized operations that also supports a rewinding operation backed by a LIFO stack.

Since: 1.5.0.0

Documentation

data RewindQueue a

Concrete FIFO Queue, with amortized constant operations.

Also keeps history of dequeued values, which can be undone in a LIFO manner.

Since: 1.5.0.0

Constructors

RewindQueue

Fields

• queue :: Queue a
• undo :: [a]
• undosz :: Int

Instances

QueueLike RewindQueue

Defined in Parsley.Internal.Common.RewindQueue

Methods

empty :: RewindQueue a

null :: RewindQueue a -> Bool

size :: RewindQueue a -> Int

enqueue :: a -> RewindQueue a -> RewindQueue a

dequeue :: RewindQueue a -> (a, RewindQueue a)

poke :: (a -> a) -> RewindQueue a -> (a, RewindQueue a)

enqueueAll :: [a] -> RewindQueue a -> RewindQueue a

Eq a => Eq (RewindQueue a)

Defined in Parsley.Internal.Common.RewindQueue.Impl

Methods

(==) :: RewindQueue a -> RewindQueue a -> Bool

(/=) :: RewindQueue a -> RewindQueue a -> Bool

Show a => Show (RewindQueue a)

Defined in Parsley.Internal.Common.RewindQueue.Impl

Methods

showsPrec :: Int -> RewindQueue a -> ShowS

show :: RewindQueue a -> String

showList :: [RewindQueue a] -> ShowS

empty :: RewindQueue a

Construct an empty queue.

Since: 1.5.0.0

enqueue :: a -> RewindQueue a -> RewindQueue a

Adds an element onto the end of the queue.

Since: 1.5.0.0

enqueueAll :: [a] -> RewindQueue a -> RewindQueue a

Adds each of the elements onto the queue, from left-to-right.

Since: 1.5.0.0

dequeue :: RewindQueue a -> (a, RewindQueue a)

Removes an element from the front of the queue.

Since: 1.5.0.0

poke :: (a -> a) -> RewindQueue a -> (a, RewindQueue a)

modifies the head of the queue, without removal. Returns the old head

Since: 2.1.0.0

rewind :: Int -> RewindQueue a -> RewindQueue a

Undoes the last \(n\) dequeue operations but only if there are that many available undos. Otherwise, it will throw an error.

Since: 1.5.0.0

null :: RewindQueue a -> Bool

Is the queue empty?

Since: 1.5.0.0

size :: RewindQueue a -> Int

Returns how many elements are in the queue.

Since: 1.5.0.0

foldr :: (a -> b -> b) -> b -> RewindQueue a -> b

Folds the values in the queue. Undo history is not included.

Since: 1.5.0.0

toList :: RewindQueue a -> [a]

Converts this queue into a list. Undo history is discarded.

Since: 1.5.0.0