pure-priority-queue-0.12: A pure priority queue.

Data.PurePriorityQueue

Description

A pure priority queue.

Because many function names clash with Prelude names, this module is usually imported `qualified`, e.g.,

```  import qualified Data.PurePriorityQueue as PQ
```

This implementation is built 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.

Synopsis

# Documentation

data MinMaxQueue p a Source

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

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)

O(1) An empty priority queue.

null :: MinMaxQueue p a -> BoolSource

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

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

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

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

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 aSource

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.

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

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)Source

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 pSource

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

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

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

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

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

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

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 -> IntSource

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

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

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

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

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

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

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.