Scheme pass-by-reference

Question

How can I pass a variable by reference in scheme?

An example of the functionality I want:

(define foo
  (lambda (&x)
    (set! x 5)))

(define y 2)

         


        

Answer 1

You probably have use too much of C, PHP or whatever. In scheme you don't want to do stuff like pass-by-*. Understand first what scope mean and how the different implementation behave (in particular try to figure out what is the difference between LISP and Scheme).

By essence a purely functional programming language do not have side effect. Consequently it mean that pass-by-ref is not a functional concept.