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world with arb numbers

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svn: r6131
This commit is contained in:
Matthias Felleisen 2007-05-03 21:50:46 +00:00
parent fa2b488b75
commit 7c43d47312
1 changed files with 16 additions and 8 deletions
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24
collects/htdp/world.ss
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@ -223,6 +223,9 @@ Matthew
[(w h delta world animated-gif)
(check-pos 'big-bang w "first")
(check-pos 'big-bang h "second")
;; ============================================
;; WHAT IF THEY ARE NOT INTs?
;; ============================================
(check-arg 'big-bang
(and (number? delta) (<= 0 delta 1000))
"number [of seconds] between 0 and 1000"
@ -233,13 +236,18 @@ Matthew
"boolean expected"
"fifth"
animated-gif)
(when (vw-init?) (error 'big-bang "big-bang already called once"))
(install-world delta world) ;; call first to establish a visible world
(set-and-show-frame w h animated-gif) ;; now show it
(unless animated-gif (set! add-event void)) ;; no recording if image undesired
(set! *the-delta* delta)
#t]))
(let ([w (coerce w)]
[h (coerce h)])
(when (vw-init?) (error 'big-bang "big-bang already called once"))
(install-world delta world) ;; call first to establish a visible world
(set-and-show-frame w h animated-gif) ;; now show it
(unless animated-gif (set! add-event void)) ;; no recording if image undesired
(set! *the-delta* delta)
#t)]))
;; Number -> Int
(define (coerce x) (inexact->exact (floor x)))
(define *the-delta* 0.0)
(define (end-of-time s)
@ -315,7 +323,7 @@ Matthew
;; Symbol Any String -> Void
(define (check-pos tag c rank)
(check-arg tag (and (number? c) (integer? c) (>= c 0))
(check-arg tag (and (number? c) (> (coerce c) 0))
"positive integer" rank c))
;; Symbol Any String String *-> Void