I'm trying to do the exercise 2.12 of the book Essential of programing languages 3rd edition.
They ask me to do a procedural representation for a stack, like they did in the example of page 40 with enviroment.
This is the example.
(define empty-env (lambda () (lambda (search-var) (report-no-binding-found search-var)) ) ) (define extend-env (lambda (saved-var saved-val saved-env) (lambda (search-var) (if (eqv? search-var saved-var) saved-val (apply-env saved-env search-var) ) )) ) (define apply-env (lambda (env search-var) (env search-var)) )
In the exercise they ask me for the next procedures:
push, pop, top, and empty-stack?
I think I did the push, top and empty-stack. But I can't figure out how to do the pop.