;;; TAKL -- The TAKeuchi function using lists as counters.
 
(library (rnrs-benchmarks takl)
  (export main)
  (import (rnrs) (rnrs-benchmarks))
  
  (define (listn n)
    (if (= n 0)
      '()
      (cons n (listn (- n 1)))))
   
  (define l18 (listn 18))
  (define l12 (listn 12))
  (define  l6 (listn 6))
   
  (define (mas x y z)
    (if (not (shorterp y x))
        z
        (mas (mas (cdr x) y z)
             (mas (cdr y) z x)
             (mas (cdr z) x y))))
   
  (define (shorterp x y)
    (and (not (null? y))
         (or (null? x)
             (shorterp (cdr x)
                       (cdr y)))))
   
  (define (main . args)
    (run-benchmark
      "takl"
      takl-iters
      (lambda (result) (equal? result '(7 6 5 4 3 2 1)))
      (lambda (x y z) (lambda () (mas x y z)))
      l18
      l12
      l6)))