(Nils' Scheme Snippets)

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(replace form_old form_new pair) => pair

Purpose

Replace elements of a pair.

Arguments

form_old	element to replace
form_new	element to insert in the place of form_old

Example

(replace 'x 'y '(lambda (x) x)) => (lambda (y) y)

(define (replace old new form)
  (cond
    ((equal? form old) new)
    ((pair? form)
      (cons (replace old new (car form))
            (replace old new (cdr form))))
    (else form)))

(Nils' Scheme Snippets)

(replace formold formnew pair) => pair

(replace form_old form_new pair) => pair