Programmation déclarative - Q5 - 08/2011

(define (str-mult n)
  (letrec
      ((inner (lambda (m)
                (cons-stream m (inner (+ m n)))
                )
              ))
    (inner n)
    )
  )

(define (fusion str1 str2 str3)
  (let*
      ((minimum (min (head str1) (head str2) (head str3)))
       (remove-head-if-min (lambda (str mini)
                             (if (= mini (head str))
                                 (tail str)
                                 str)
                             )
                           )
       (sttr1 (remove-head-if-min str1 minimum))
       (sttr2 (remove-head-if-min str2 minimum))
       (sttr3 (remove-head-if-min str3 minimum))
       )
    (cons-stream minimum (fusion sttr1 sttr2 sttr3))
    )
  )

(define (hamming)
  (fusion (str-mult 2) (str-mult 3) (str-mult 5))
  )