From e5a28ba41107c6892c62cf23a4a9a93d1bb27085 Mon Sep 17 00:00:00 2001
From: Matthias Felleisen <matthias@racket-lang.org>
Date: Wed, 9 Jul 2008 17:51:05 +0000
Subject: [PATCH] svn: r10701

---
 collects/htdp/world.ss | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/collects/htdp/world.ss b/collects/htdp/world.ss
index 3cce3bd81f..654c274f23 100644
--- a/collects/htdp/world.ss
+++ b/collects/htdp/world.ss
@@ -1,3 +1,15 @@
+#|
+ workshop experience: 
+
+   stop-when should have a different signature:
+    stop-when : (World -> Boolean) (World -> Image) 
+
+   (stop-when C F) should have this semantics:
+    on each assignment to world,
+    (begin 
+      (set! current-world new-world)
+      (when (C current-world) (render (F current-world))))
+|#
 ;; Fri Jul  4 10:25:47 EDT 2008: added ke=? and key-event? 
 ;; Mon Jun 16 15:38:14 EDT 2008: removed end-of-time and provided stop-when 
 ;;                               also allow repeated setting of callbacks now