simple example

racket/typed/examples/roles/ping-pong.rkt

@@ -0,0 +1,23 @@
+#lang typed/syndicate/roles
+
+;; Expected Output
+;; pong: 8339
+
+(define-type-alias ds-type
+  (U (Tuple String Int)
+     (Observe (Tuple String ★/t))))
+
+(dataspace ds-type
+  (spawn ds-type
+    (start-facet echo
+      (fields)
+      (on (asserted (tuple "ping" (bind x Int)))
+          (start-facet _
+            (fields)
+            (assert (tuple "pong" x))))))
+  (spawn ds-type
+    (start-facet serve
+      (fields)
+      (assert (tuple "ping" 8339))
+      (on (asserted (tuple "pong" (bind x Int)))
+          (printf "pong: ~v\n" x)))))