12 lines
180 B
PostScript
12 lines
180 B
PostScript
|
% empty? is already defined.
|
||
|
|
/push {exch cons}.
|
||
|
|
/pop {uncons exch pop}.
|
||
|
|
[2 3 4 5 6] 1 push
|
||
|
|
= [1 2 3 4 5 6]
|
||
|
|
[1 2 3 4 5 6] pop
|
||
|
|
=[2 3 4 5 6]
|
||
|
|
[2 3 4 5 6] empty?
|
||
|
|
=false
|
||
|
|
[] empty?
|
||
|
|
=true
|