Data.PurePriorityQueue.Internal

This module exposes the internals of a pure priority queue, implemented on top of Data.Map.

Estimates of worst-case time complexity are given. The value n is the number of elements in the queue. The value p is the cardinality of the set of priorities of the elements in the queue. p is never greater than n.

Documentation

newtype MinMaxQueue p a

A queue of values of type a with priority of type p.

Constructors

MinMaxQueue

Fields

unMinMaxQueue :: Map p [a]

Instances

Functor (MinMaxQueue p)

Foldable (MinMaxQueue p)

(Eq p, Eq a) => Eq (MinMaxQueue p a)

(Ord p, Ord a) => Ord (MinMaxQueue p a)

Ord p => Monoid (MinMaxQueue p a)

empty :: MinMaxQueue p a

O(1) An empty priority queue.

null :: MinMaxQueue p a -> Bool

O(1) Test whether a priority queue is empty.

insert :: Ord p => a -> p -> MinMaxQueue p a -> MinMaxQueue p a

O(log p) Insert a value with given priority into a priority queue.

deleteMin :: Ord p => MinMaxQueue p a -> MinMaxQueue p a

O(log p) Remove the value with the minimum priority from the queue.

If the queue is empty, deleteMin returns empty. If multiple values share the minimum priority, the most recently added will be removed.

deleteMax :: Ord p => MinMaxQueue p a -> MinMaxQueue p a

O(log p) Remove the value with the maximum priority from the queue.

If the queue is empty, deleteMax returns empty. If multiple values share the maximum priority, the most recently added will be removed.

viewWith

Arguments

:: Ord p

=> (Map p [a] -> Maybe ((p, [a]), Map p [a]))

The view function

-> MinMaxQueue p a

The priority queue

-> Maybe ((a, p), MinMaxQueue p a)

Applies a Data.Map.Map view function to a given priority queue.

minView :: Ord p => MinMaxQueue p a -> Maybe ((a, p), MinMaxQueue p a)

O(log p) View a priority queue to get the (value, priority) pair with the lowest priority and the remainder of the queue.

If multiple values share the lowest priority, the most recently added will be returned.

maxView :: Ord p => MinMaxQueue p a -> Maybe ((a, p), MinMaxQueue p a)

O(log p) View a priority queue to get the (value, priority) pair with the highest priority and the remainder of the queue.

If multiple values share the highest priority, the most recently added will be returned.

minPriority :: Ord p => MinMaxQueue p a -> Maybe p

O(log p) Get the minimum priority of the elements in the queue.

maxPriority :: Ord p => MinMaxQueue p a -> Maybe p

O(log p) Get the maximum priority of the elements in the queue.

foldWithPriority :: Ord p => (p -> a -> b -> b) -> b -> MinMaxQueue p a -> b

O(n) Fold the priorities and values of a priority queue.

splitByPriority :: Ord p => p -> MinMaxQueue p a -> (MinMaxQueue p a, MinMaxQueue p a)

O(log p) Split a priority queue q into two queues (q1, q2) by the given priority p, such that q1 contains exactly the entries with priority less than p, and q2 containes exactly the entries with priority greater than or equal to p.

size :: Ord p => MinMaxQueue p a -> Int

O(n) The number of entries in a priority queue.

filter :: Ord p => (a -> Bool) -> MinMaxQueue p a -> MinMaxQueue p a

O(n) Filter all values that satisfy the predicate.

filterWithPriority :: Ord p => (a -> p -> Bool) -> MinMaxQueue p a -> MinMaxQueue p a

O(n) Filter all entries that satisfy the predicate.

toAscList :: Ord p => MinMaxQueue p a -> [(a, p)]

O(n) Convert the priority queue into a list of (value, priority) pairs in ascending priority.

If multiple values share the same priority, the most recently added entries will come first.