RosettaCodeData/Task/Same-Fringe/Racket/same-fringe-2.rkt
2015-11-18 06:14:39 +00:00

15 lines
494 B
Racket

#lang racket
(define (fringe->channel tree)
(define ch (make-channel))
(thread (λ() (let loop ([tree tree])
(if (list? tree) (for-each loop tree) (channel-put ch tree)))
(channel-put ch (void)))) ; mark the end
ch)
(define (same-fringe? tree1 tree2)
(define ch1 (fringe->channel tree1))
(define ch2 (fringe->channel tree2))
(let loop ()
(let ([x1 (channel-get ch1)] [x2 (channel-get ch2)])
(and (equal? x1 x2) (or (void? x1) (loop))))))