Message delivery now catches exceptions and prints warning.

diff --git a/sam.scm b/sam.scm
index ed69987..8f2741f 100644 (file)
--- a/sam.scm
+++ b/sam.scm
@@ -77,12 +77,15 @@
   (let ((id (address-id address)))
     (let ((behaviour (hash-table-ref/default actor-table id '())))
       (if (null? behaviour)
-          (print "Warning: discarded message " message
+          (print "## Warning: discarded message " message
                  " to unknown actor id " id)
-          (match (apply (hash-table-ref actor-table id) (cons address message))
-            ('done (hash-table-delete! actor-table id))
-            ('sleep 'do-nothing)
-            (new-beh (hash-table-set! actor-table id new-beh)))))))
+          (condition-case
+              (match (apply behaviour (cons address message))
+                ('done (hash-table-delete! actor-table id))
+                ('sleep 'do-nothing)
+                (new-beh (hash-table-set! actor-table id new-beh)))
+            ((exn)
+             (print "## Warning: actor id " id " crashed evaluating message " message)))))))
 
 ;; Scheduler