util.match の練習。

match-renshu.scm

(use util.match)

(define tree
  '((((1 2 3) (4 5) 6) ((7 8) 9 (10 11 12))) 13))

(define (match-tree t)
  (match t
    ((? number? n)
     (print "number " n))
    ((children ...)
     (print "children")
     (for-each
      (lambda (child)
        (match-tree child))
      children))
    ))

;(match-tree tree)


(define tree-2
  '((1 "two")
    ("three" 4)))

(define (match-tree-2 t)
  (match t
         ((((? number? n1) (? string? str1))
           ((? number? n2) (? string? str2)))
          (print "number " n1 n2)
          (print "string " str1 str2))

         ((((? number? n1) (? string? str1))
           ((? string? str2) (? number? n2)))
          (print "number " n1 n2)
          (print "string " str1 str2))

         ((((? string? str1) (? number? n1))
           ((? number? n2) (? string? str2)))
          (print "number " n1 n2)
          (print "string " str1 str2))

         ((((? string? str1) (? number? n1))
           ((? string? str2) (? number? n2)))
          (print "number " n1 n2)
          (print "string " str1 str2))

         ))

;(match-tree-2 tree-2)

(define (match-tree-3 t)
  (define (match-tip p)
    (match p
           ((? number? n)
            (print "number " n))
           ((? string? str)
            (print "number " str))))

  (define (match-part p)
    (match p
           ((tips ...)
            (for-each match-tip tips))))

  (match t
         ((part ...)
          (for-each match-part part))))

(match-tree-3 tree-2)