70 lines
1.7 KiB
Racket
70 lines
1.7 KiB
Racket
#lang racket/base
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(require racket/list)
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(require racket/port)
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(require racket/match)
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(require "os2.rkt")
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(require "fake-tcp.rkt")
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(define (term->bytes v)
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(with-output-to-bytes
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(lambda () (write v) (newline))))
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;;---------------------------------------------------------------------------
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(define listener
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(nested-vm
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(at-meta-level
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(role (tcp-listener 5999)
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#:topic t
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#:on-presence
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(spawn (connection-handler t))))))
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(define (connection-handler t)
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(define me (gensym 'user))
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(define-values (cin cout in-t out-t)
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(tcp-accept t))
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(transition 'no-state
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(net-roles me cin cout in-t out-t)
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(chat-roles me cout)))
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(define (net-roles me cin cout in-t out-t)
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(at-meta-level
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(cout (term->bytes `(you-are ,me)))
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(cin (tcp-mode 'lines))
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(cin (tcp-credit 1))
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(role out-t)
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(role in-t
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#:on-absence (kill)
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[(tcp-channel _ _ (? bytes? line))
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(list (at-meta-level
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(cin (tcp-credit 1)))
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(send-message
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`(,me says ,line)))])))
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(define (chat-roles me cout)
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(define (announce t did-what)
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(define who (first (topic-pattern t)))
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(unless (equal? who me)
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(at-meta-level
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(cout (term->bytes
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`(,who ,did-what))))))
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(list
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(role (topic-publisher
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`(,me says ,(wild))))
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(role (topic-subscriber
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`(,(wild) says ,(wild)))
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#:topic t
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#:on-presence (announce t 'arrived)
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#:on-absence (announce t 'departed)
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[msg (at-meta-level
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(cout (term->bytes msg)))])))
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(ground-vm (spawn tcp-driver)
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(spawn listener))
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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