R: Class "queue"

queue-class {filehash} | R Documentation

## Class "queue"

### Description

A queue implementation using a `filehash` database

### Objects from the Class

Objects can be created by calls of the form `new("queue", ...)` or by calling `createQ`. Existing queues can be initialized with `initQ`.

### Slots

`queue`:

  Object of class `"filehashDB1"`

`name`:

  Object of class `"character"`: the name of the queue (default is the file name in which the queue data are stored)

### Methods

isEmpty

  `signature(db = "queue")`: returns `TRUE`/`FALSE` depending on whether there are elements in the queue.

pop

  `signature(db = "queue")`: returns the value of the "top" (i.e. head) of the queue and subsequently removes that element from the queue; an error is signaled if the queue is empty

push

  `signature(db = "queue")`: adds an element to the tail ("bottom") of the queue

show

  `signature(object = "queue")`: prints the name of the queue

top

  `signature(db = "queue")`: returns the value of the "top" (i.e. head) of the queue; an error is signaled if the queue is empty

### Author(s)

Roger D. Peng rpeng@jhsph.edu

### Examples

    showClass("queue")

[Package filehash version 2.4-1 Index]