Channel based chat example

client.scm

(use unix-sockets channel srfi-18 parley)

(define output-channel
  (make-channel))

(channel-enqueue output-channel (parley "Your name: "))

(define-values (in out)
  (unix-connect "sock"))

(flush-channel-to-output-port
 output-channel out write-line)

(thread-start!
 (lambda ()
   (let loop ()
     (let ((line (parley "")))
       (unless (eof-object? line)
         (channel-enqueue output-channel line)
         (loop))))))

(define-values (next channel)
  (siphon-input-port in read-line))

(on-channel-receive channel print)

(let loop ()
  (when (next)
    (loop)))

server.scm

(use unix-sockets channel srfi-18)

(define socket-file "sock")

(when (file-exists? socket-file)
  (delete-file socket-file))

(define listener
  (unix-listen socket-file))

(define broadcast-channel
  (make-channel))

(on-channel-receive broadcast-channel print)

(let loop ()
  (define-values (in out) (unix-accept listener))

  (thread-start!
   (lambda ()
     (define name (read-line in))
     (print name " joined")

     (flush-channel-to-output-port
      broadcast-channel out write-line)

     (define-values (next channel)
       (siphon-input-port in read-line))

     (siphon-channel
      (map-channel
       channel
       (lambda (message)
         (string-append name ": " message)))
      broadcast-channel)

     (let loop ()
       (when (next)
         (loop)))))
  
  (loop))