PriorityQueue (core 5.0 API)

java.lang.Object
- fj.data.PriorityQueue<K,A>

```
public final class PriorityQueue<K,A>
extends java.lang.Object
```
A priority queue implementation backed by a FingerTree. The finger tree nodes are annotated with type K, are combined using a monoid of K and both the key and value are stored in the leaf. Priorities of the same value are returned FIFO (first in, first out).

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`contains(K k)` Does the priority k exist already?
`PriorityQueue<K,A>`	`dequeue()` Removes the node with the highest priority.
`PriorityQueue<K,A>`	`dequeue(int n)` Removes the top n elements with the highest priority.
`static <K,A> PriorityQueue<K,A>`	`empty(Monoid<K> m, Equal<K> e)` Creates an empty priority queue.
`static <A> PriorityQueue<java.lang.Integer,A>`	`emptyInt()` An empty priority queue with integer priorities.
`PriorityQueue<K,A>`	`enqueue(java.lang.Iterable<P2<K,A>> it)` Adds nodes using the iterable of products with priority k and value a.
`PriorityQueue<K,A>`	`enqueue(K k, A a)` Adds a node with priority k and value a.
`PriorityQueue<K,A>`	`enqueue(List<P2<K,A>> list)` Adds nodes using the list of products with priority k and value a.
`PriorityQueue<K,A>`	`enqueue(P2<K,A> p)` Adds a node with priority k and value a.
`PriorityQueue<K,A>`	`filterKeys(F<K,java.lang.Boolean> f)` Filters the nodes based on the annotation of each node.
`PriorityQueue<K,A>`	`filterValues(F<A,java.lang.Boolean> f)` Filters nodes based on the value inside each node.
`boolean`	`isEmpty()` Is the tree empty?
`boolean`	`isEqual(Ord<K> ok, K k)`
`boolean`	`isGreaterThan(Ord<K> ok, K k)`
`boolean`	`isLessThan(Ord<K> ok, K k)` Does the top of the queue have lower priority than k?
`<B> PriorityQueue<K,B>`	`map(F<A,B> f)` Maps the values in each node with function f.
`static <K,A> PriorityQueue<K,A>`	`priorityQueue(Equal<K> e, FingerTree<K,P2<K,A>> ft)` Creates a priority queue from a finger tree.
`List<P2<K,A>>`	`toList()` Returns a list of products with priority k and value a.
`Option<P2<K,A>>`	`top()` If the tree is not empty, returns the node with highest priority otherwise returns nothing.
`P2<Option<P2<K,A>>,PriorityQueue<K,A>>`	`topDequeue()` Returns a tuple of the node with the highest priority and the rest of the priority queue.
`List<P2<K,A>>`	`topN()` Returns all the elements of the queue with the highest (same) priority.
`Stream<P2<K,A>>`	`toStream()` Returns a stream of products with priority k and value a.
`java.lang.String`	`toString()`
`<B> B`	`unqueue(B empty, F2<P2<K,A>,PriorityQueue<K,A>,B> topDequeue)` Performs a reduction on this priority queue using the given arguments.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Method Detail
  - priorityQueue
```
public static <K,A> PriorityQueue<K,A> priorityQueue(Equal<K> e,
                                                     FingerTree<K,P2<K,A>> ft)
```
    Creates a priority queue from a finger tree.
  - empty
```
public static <K,A> PriorityQueue<K,A> empty(Monoid<K> m,
                                             Equal<K> e)
```
    Creates an empty priority queue.
    
    Parameters:
    
    m - A monoid to combine node annotations.
    
    e - A value to compare key equality.
  - emptyInt
```
public static <A> PriorityQueue<java.lang.Integer,A> emptyInt()
```
    An empty priority queue with integer priorities.
  - map
```
public <B> PriorityQueue<K,B> map(F<A,B> f)
```
    Maps the values in each node with function f.
  - filterValues
```
public PriorityQueue<K,A> filterValues(F<A,java.lang.Boolean> f)
```
    Filters nodes based on the value inside each node.
  - filterKeys
```
public PriorityQueue<K,A> filterKeys(F<K,java.lang.Boolean> f)
```
    Filters the nodes based on the annotation of each node.
  - isEmpty
```
public boolean isEmpty()
```
    Is the tree empty?
  - top
```
public Option<P2<K,A>> top()
```
    If the tree is not empty, returns the node with highest priority otherwise returns nothing.
  - topN
```
public List<P2<K,A>> topN()
```
    Returns all the elements of the queue with the highest (same) priority.
  - enqueue
```
public PriorityQueue<K,A> enqueue(K k,
                                  A a)
```
    Adds a node with priority k and value a. This operation take O(1).
  - enqueue
```
public PriorityQueue<K,A> enqueue(List<P2<K,A>> list)
```
    Adds nodes using the list of products with priority k and value a. This operation takes O(list.length()).
  - contains
```
public boolean contains(K k)
```
    Does the priority k exist already?
  - enqueue
```
public PriorityQueue<K,A> enqueue(java.lang.Iterable<P2<K,A>> it)
```
    Adds nodes using the iterable of products with priority k and value a.
  - enqueue
```
public PriorityQueue<K,A> enqueue(P2<K,A> p)
```
    Adds a node with priority k and value a. This operation take O(1).
  - dequeue
```
public PriorityQueue<K,A> dequeue()
```
    Removes the node with the highest priority.
  - topDequeue
```
public P2<Option<P2<K,A>>,PriorityQueue<K,A>> topDequeue()
```
    Returns a tuple of the node with the highest priority and the rest of the priority queue.
  - unqueue
```
public <B> B unqueue(B empty,
                     F2<P2<K,A>,PriorityQueue<K,A>,B> topDequeue)
```
    Performs a reduction on this priority queue using the given arguments.
    
    Parameters:
    
    empty - The value to return if this queue is empty.
    
    topDequeue - The function to apply to the top priority element and the tail of the queue (without its top element).
    
    Returns:
    
    A reduction on this queue.
  - dequeue
```
public PriorityQueue<K,A> dequeue(int n)
```
    Removes the top n elements with the highest priority.
  - isLessThan
```
public boolean isLessThan(Ord<K> ok,
                          K k)
```
    Does the top of the queue have lower priority than k?
  - isGreaterThan
```
public boolean isGreaterThan(Ord<K> ok,
                             K k)
```
  - isEqual
```
public boolean isEqual(Ord<K> ok,
                       K k)
```
  - toStream
```
public Stream<P2<K,A>> toStream()
```
    Returns a stream of products with priority k and value a.
  - toList
```
public List<P2<K,A>> toList()
```
    Returns a list of products with priority k and value a.
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class PriorityQueue<K,A>

Method Summary

Methods inherited from class java.lang.Object

Method Detail

priorityQueue

empty

emptyInt

map

filterValues

filterKeys

isEmpty

top

topN

enqueue

enqueue

contains

enqueue

enqueue

dequeue

topDequeue

unqueue

dequeue

isLessThan

isGreaterThan

isEqual

toStream

toList

toString