syndicate-2017/racket/doc/chat.rkt.txt

32 lines
1.4 KiB
Racket

#lang prospect ;; -*- racket -*-
(require (only-in racket/string string-trim))
(require "../drivers/tcp.rkt")
(require "../demand-matcher.rkt")
(define (spawn-session them us)
(define user (gensym 'user))
(define (send-to-remote fmt . vs)
(send! (at-meta (tcp-channel us them (string->bytes/utf-8 (apply format fmt vs))))))
(define (say who fmt . vs)
(unless (equal? who user) (send-to-remote "~a ~a\n" who (apply format fmt vs))))
(actor (send-to-remote "Welcome, ~a.\n" user)
(until (retracted (advertise (tcp-channel them us ?)) #:meta-level 1)
(assert (advertise (tcp-channel us them ?) #:meta-level 1))
(assert (advertise `(,user says ,?)))
(on (asserted (advertise `(,$who says ,?))) (say who "arrived."))
(on (retracted (advertise `(,$who says ,?))) (say who "departed."))
(on `(,$who says ,$what) (say who "says: ~a" what))
(on (message (at-meta (tcp-channel them us $bs)))
(define input-string (string-trim (bytes->string/utf-8 bs)))
(if (equal? input-string "quit-network")
(assert! 'quit-network)
(send! `(,user says ,input-string)))))
(send-to-remote "Goodbye!\n")))
(spawn-tcp-driver)
(let ((us (tcp-listener 5999)))
(group (until (asserted 'quit-network)
(on (asserted (advertise (tcp-channel $them us ?)) #:meta-level 1)
(spawn-session them us)))))