30 lines
1.1 KiB
Racket
30 lines
1.1 KiB
Racket
#lang syndicate
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(require syndicate/protocol/advertise)
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(require/activate syndicate/drivers/tcp)
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(require (only-in racket/string string-trim))
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(struct says (who what) #:prefab)
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(struct present (who) #:prefab)
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(define us (tcp-listener 5999))
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(spawn (assert (advertise (observe (tcp-channel _ us _))))
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(during/spawn (advertise (tcp-channel $them us _))
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(assert (advertise (tcp-channel us them _)))
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(define (send-to-remote fmt . vs)
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(send! (tcp-channel us them (string->bytes/utf-8 (apply format fmt vs)))))
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(define user (gensym 'user))
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(on-start (send-to-remote "Welcome, ~a.\n" user))
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(assert (present user))
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(on (message (tcp-channel them us $bs))
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(send! (says user (string-trim (bytes->string/utf-8 bs)))))
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(during (present $who)
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(unless (equal? who user)
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(on-start (send-to-remote "~a arrived.\n" who))
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(on-stop (send-to-remote "~a departed.\n" who))
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(on (message (says who $what)) (send-to-remote "~a says: ~a\n" who what))))))
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