Queue

Edit on GitHub

An immutable queue implementation. A queue is a FIFO (first-in-first-out) data structure where new values are added to the end and retrieved or removed from the beginning.

Added in 0.2.0

No other changes yet.

import Queue from "queue"

Types

Type declarations included in the Queue module.

Queue.Queue

type Queue<a>

Values

Functions for working with queues.

Queue.make

Added in 0.2.0

No other changes yet.

make : () -> Queue<a>

Creates an empty queue.

Returns:

type	description
`Queue<a>`	An empty queue

Queue.isEmpty

Added in 0.2.0

No other changes yet.

isEmpty : Queue<a> -> Bool

Checks if the given queue contains any values.

Parameters:

param	type	description
`queue`	`Queue<a>`	The queue to check

Returns:

type	description
`Bool`	`true` if the given queue is empty or `false` otherwise

Queue.peek

Added in 0.3.2

version	changes
`0.2.0`	Originally named `head`
`0.3.2`	Deprecated `head` function
`0.4.0`	Removed `head` function

peek : Queue<a> -> Option<a>

Returns the value at the beginning of the queue. It is not removed from the queue.

Parameters:

param	type	description
`queue`	`Queue<a>`	The queue to inspect

Returns:

type	description
`Option<a>`	`Some(value)` containing the value at the beginning of the queue, or `None` if the queue is empty

Queue.push

Added in 0.3.2

version	changes
`0.2.0`	Originally named `enqueue`
`0.3.2`	Deprecated `enqueue` function
`0.4.0`	Removed `enqueue` function

push : (a, Queue<a>) -> Queue<a>

Adds a value to the end of the queue.

Parameters:

param	type	description
`value`	`a`	The value to append
`queue`	`Queue<a>`	The queue to update

Returns:

type	description
`Queue<a>`	An updated queue

Queue.pop

Added in 0.3.2

version	changes
`0.2.0`	Originally named `dequeue`
`0.3.2`	Deprecated `dequeue` function
`0.4.0`	Removed `dequeue` function

pop : Queue<a> -> Queue<a>

Dequeues the next value in the queue.

Parameters:

param	type	description
`queue`	`Queue<a>`	The queue to change

Returns:

type	description
`Queue<a>`	An updated queue

Queue.size

Added in 0.3.2

No other changes yet.

size : Queue<a> -> Number

Get the number of values in a queue.

Parameters:

param	type	description
`queue`	`Queue<a>`	The queue to inspect

Returns:

type	description
`Number`	The number of values in the queue