syndicate-rkt/OLD-syndicate-examples/chat-server-nested-dataspac...

33 lines
1.4 KiB
Racket

;;; SPDX-License-Identifier: LGPL-3.0-or-later
;;; SPDX-FileCopyrightText: Copyright © 2010-2021 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
#lang syndicate
(require/activate syndicate/drivers/tcp)
(require racket/format)
(message-struct speak (who what))
(assertion-struct present (who))
(dataspace
(spawn #:name 'chat-server
(during/spawn (inbound (tcp-connection $id (tcp-listener 5999)))
#:name (list 'chat-connection id)
(assert (outbound (tcp-accepted id)))
(on-start (send! (outbound (credit (tcp-listener 5999) 1)))
(send! (outbound (credit tcp-in id 1))))
(let ((me (gensym 'user)))
(assert (present me))
(on (message (inbound (tcp-in-line id $bs)))
(match bs
[#"/quit" (stop-current-facet)]
[#"/stop-server" (quit-dataspace!)]
[_ (send! (speak me (bytes->string/utf-8 bs)))
(send! (outbound (credit tcp-in id 1)))])))
(during (present $user)
(on-start (send! (outbound (tcp-out id (string->bytes/utf-8 (~a user " arrived\n"))))))
(on-stop (send! (outbound (tcp-out id (string->bytes/utf-8 (~a user " left\n"))))))
(on (message (speak user $text))
(send!
(outbound (tcp-out id (string->bytes/utf-8 (~a user " says '" text "'\n"))))))))))