47 lines
1.4 KiB
Racket
47 lines
1.4 KiB
Racket
#lang marketplace
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(spawn-vm
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(at-meta-level
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(observe-publishers (tcp-channel ? (tcp-listener 5999) ?)
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(match-conversation (tcp-channel them us _)
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(on-presence (spawn (chat-session them us)))))))
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(define (chat-session them us)
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(define user (gensym 'user))
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(transition stateless
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(listen-to-user user them us)
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(speak-to-user user them us)))
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(define (listen-to-user user them us)
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(list
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(at-meta-level
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(subscriber (tcp-channel them us ?)
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(on-absence (quit))
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(on-message
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[(tcp-channel _ _ (? bytes? text))
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(send-message `(,user says ,text))])))
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(publisher `(,user says ,?))))
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(define (speak-to-user user them us)
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(define (say fmt . args)
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(at-meta-level
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(send-message
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(tcp-channel us them (apply format fmt args)))))
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(define (announce who did-what)
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(unless (equal? who user)
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(say "~s ~s.~n" who did-what)))
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(list
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(say "You are ~s.~n" user)
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(at-meta-level
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(publisher (tcp-channel us them ?)))
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(subscriber `(,? says ,?)
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(match-conversation `(,who says ,_)
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(on-presence (announce who 'arrived))
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(on-absence (announce who 'departed))
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(on-message [`(,who says ,what)
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(say "~a: ~a" who what)])))))
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