/*REXX program to demonstrate FIFO queue usage by some simple operations*/
call viewQueue
a="Fred"
push                                   /*puts a  "null" on top of queue.*/
push a 2                               /*puts  "Fred 2" on top of queue.*/
call viewQueue

queue "Toft 2"                         /*put  "Toft 2"  on queue bottom.*/
queue                                  /*put a "null"   on queue bottom.*/
call viewQueue
                  do n=1  while queued()\==0
                  parse pull xxx
                  say "queue entry" n': ' xxx
                  end   /*n*/
call viewQueue
exit                                   /*stick a fork in it, we're done.*/
/*──────────────────────────────────viewQueue subroutine────────────────*/
viewQueue:  if queued()==0 then say 'Queue is empty'
                           else say 'There are' queued() 'elements in the queue'
return