Exercise 1.4.12
More PUSH and POP
Like cons, push isn't limited to the existing type of its target.
* *stack*
NIL
* (push 1 *stack*)
(1)
* (push "b" *stack*)
("b" 1)
* (push 'c *stack*)
(c "b" 1)
* (push (list 4 5) *stack*)
((4 5) C "a" 1)
* *stack*
((4 5) C "a" 1)
Learn Lisp The Hard Way by "the Phoeron" Colin J.E. Lupton is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.