Plain-racket echo variation.

marketplace/examples/echo-plain.rkt

@@ -0,0 +1,18 @@
+#lang racket/base
+;; Plain Racket version, using (require) instead of #lang marketplace.
+
+(require marketplace/sugar-untyped)
+(require marketplace/drivers/tcp-bare)
+
+(define (echoer from to)
+  (transition/no-state
+    (endpoint
+      #:subscriber (tcp-channel from to ?)
+      #:on-absence (quit)
+      [(tcp-channel _ _ data)
+       (send-message (tcp-channel to from data))])))
+
+(ground-vm tcp
+	   (endpoint #:subscriber (tcp-channel ? (tcp-listener 5999) ?)
+		     #:conversation (tcp-channel from to _)
+		     #:on-presence (spawn #:child (echoer from to))))