queue-class: Class "queue"
Description
A queue implementation using a filehash databaseObjects 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