racket/collects/2htdp/tests/universe-restart.rkt
2013-01-23 14:45:07 -05:00

47 lines
1.5 KiB
Racket

#lang racket
(module drop-on-message racket
(require 2htdp/universe 2htdp/image)
(define (u)
(universe 0
(on-new (lambda (u w) (make-bundle (+ u 1) '() '())))
(on-tick (lambda (w) (make-bundle w '() '())) 1 5)
(on-msg (lambda (u w m) (make-bundle (- u 1) '() (list w))))
(state #t)))
(define (w n)
(big-bang 3
[to-draw (lambda (w) (overlay (text (number->string w) 22 'black) (circle 100 'solid 'red)))]
[on-tick (lambda (w) (if (<= w 1) (make-package 0 n) (- w 1)))]
[register LOCALHOST]
[name n]))
(launch-many-worlds (u) (w "one") (w "two")))
(require (submod "." drop-on-message))
(module drop-bad racket
(require 2htdp/universe 2htdp/image)
(define *world* #false)
(define (u)
(universe '()
(on-new (lambda (u w) (make-bundle (cons w u) '() '())))
(on-tick (lambda (w) w) 1 5)
(on-msg (lambda (u w m)
;; set *world* to the first world that comes around, reuse
(unless *world* (set! *world* w))
(make-bundle u '() (list *world*))))))
(define (w n)
(big-bang 3
[to-draw (lambda (w) (overlay (text (number->string w) 22 'black) (circle 100 'solid 'red)))]
[on-tick (lambda (w) (if (= w 1) (make-package 0 n) (- w 1)))]
[register LOCALHOST]
[name n]))
(launch-many-worlds (u) (w "one") (w "two") (w "three")))
; (require (submod "." drop-bad))