( ﾉ╹◡◡╹)ﾉ くりかえしまくろ～～～～

example-dolist.scm

(include "./reiteration.scm")

(dolist (i '(0 1 2 3 4 5 6 7 8 9))
        (display i)
        (display " "))

reiteration.scm

(define-syntax dolist
  (syntax-rules ()
    ((_ (it seq result) body ...)
     (let loop ((xs seq))
       (if (null? xs)
           result
           (begin
             (let ((it (car xs)))
               body
               ...)
             (loop (cdr xs))))))
    ((_ (it seq) body ...)
     (let loop ((xs seq))
       (if (null? xs)
           '()
           (begin
             (let ((it (car xs)))
               body
               ...)
             (loop (cdr xs))))))
    ((_ (seq) body ...)
     (let loop ((xs seq))
       (if (null? xs)
           '()
           (begin
             body
             ...
             (loop (cdr xs))))))))

(define-syntax dotimes
  (syntax-rules ()
    ((_ (it num-expr) body ...)
     (let loop ((n 0))
       (if (< num-expr n)
           '()
           (begin
             (let ((it n))
               body
               ...)
             (loop (+ n 1))))))
    ((_ (num-expr) body ...)
     (let loop ((n 0))
       (if (< num-expr n)
           '()
           (begin
             body
             ...
             (loop (+ n 1))))))))

(define-syntax while
  (syntax-rules ()
    ((_ expr body ...)
     (let loop ()
       (if expr
           (begin
             body
             ...
             (loop))
           '())))))