sicp-2-20.scm

(define (same-parity first . rest)
  (define (collect lst test)
    (if (null? lst)
        '()
        (let ((a (car lst)) (d (cdr lst)))
          (if (test a)
              (cons a (collect d test))
              (collect d test)))))
  (cons first
        (collect rest (if (even? first) even? odd?))))