picrin/etc/R7RS/src/ctak.sch

44 lines
1.2 KiB
Scheme

;;; CTAK -- A version of the TAK procedure that uses continuations.
(import (scheme base)
(scheme read)
(scheme write))
(define (ctak x y z)
(call-with-current-continuation
(lambda (k) (ctak-aux k x y z))))
(define (ctak-aux k x y z)
(if (not (< y x))
(k z)
(call-with-current-continuation
(lambda (k)
(ctak-aux
k
(call-with-current-continuation
(lambda (k) (ctak-aux k (- x 1) y z)))
(call-with-current-continuation
(lambda (k) (ctak-aux k (- y 1) z x)))
(call-with-current-continuation
(lambda (k) (ctak-aux k (- z 1) x y))))))))
(define (main)
(let* ((count (read))
(input1 (read))
(input2 (read))
(input3 (read))
(output (read))
(s4 (number->string count))
(s3 (number->string input3))
(s2 (number->string input2))
(s1 (number->string input1))
(name "ctak"))
(run-r7rs-benchmark
(string-append name ":" s1 ":" s2 ":" s3 ":" s4)
count
(lambda ()
(ctak (hide count input1) (hide count input2) (hide count input3)))
(lambda (result) (equal? result output)))))
(include "src/common.sch")