From b7726dafb8d4b551b306f2d287f4cfb5dbb5395a Mon Sep 17 00:00:00 2001 From: Tony Garnock-Jones Date: Sat, 16 Jan 2016 18:45:44 -0500 Subject: [PATCH] Clearer example --- prospect/examples/bank-account.rkt | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/prospect/examples/bank-account.rkt b/prospect/examples/bank-account.rkt index 345e550..1afaf56 100644 --- a/prospect/examples/bank-account.rkt +++ b/prospect/examples/bank-account.rkt @@ -27,8 +27,9 @@ (assert (observe (account ?)))) (spawn (lambda (e s) - (and (patch/added? e) - (quit (list (message (alter-balance-by +100)) - (message (alter-balance-by -30)))))) + (if (and (patch? e) (matcher-non-empty? (patch-added e))) + (quit (list (message (alter-balance-by +100)) + (message (alter-balance-by -30)))) + #f)) (void) (assert (observe (observe (alter-balance-by ?)))))