19 lines
539 B
Plaintext
19 lines
539 B
Plaintext
procedure main(arglist)
|
|
queue := []
|
|
write("Usage:\nqueue x x x - x - - - - -\n\t- pops elements\n\teverything else pushes")
|
|
write("Queue is:")
|
|
every x := !arglist do {
|
|
case x of {
|
|
"-" : pop(queue) | write("pop(empty) failed.") # pop if the next arglist[i] is a -
|
|
default : put(queue,x) # push arglist[i]
|
|
}
|
|
if empty(queue) then writes("empty")
|
|
else every writes(!queue," ")
|
|
write()
|
|
}
|
|
end
|
|
|
|
procedure empty(X) #: fail if X is not empty
|
|
if *X = 0 then return
|
|
end
|