4 \alias{isEmpty,queue-method}
5 \alias{pop,queue-method}
6 \alias{push,queue-method}
7 \alias{show,queue-method}
8 \alias{top,queue-method}
11 \description{A queue implementation using a \code{filehash} database}
12 \section{Objects from the Class}{
13 Objects can be created by calls of the form \code{new("queue", ...)} or
14 by calling \code{createQ}. Existing queues can be initialized with
19 \item{\code{queue}:}{Object of class \code{"filehashDB1"}}
20 \item{\code{name}:}{Object of class \code{"character"}: the name of
21 the queue (default is the file name in which the queue data are
27 \item{isEmpty}{\code{signature(db = "queue")}: returns
28 \code{TRUE}/\code{FALSE} depending on whether there are elements
30 \item{pop}{\code{signature(db = "queue")}: returns the value of the
31 "top" (i.e. head) of the queue and subsequently removes that
32 element from the queue; an error is signaled if the queue is empty}
33 \item{push}{\code{signature(db = "queue")}: adds an element to the
34 tail ("bottom") of the queue}
35 \item{show}{\code{signature(object = "queue")}: prints the name of
37 \item{top}{\code{signature(db = "queue")}: returns the value of the
38 "top" (i.e. head) of the queue; an error is signaled if the queue
42 \author{Roger D. Peng \email{rpeng@jhsph.edu}}