Prototype state flow in Racket

#lang racket
#|
# Broker peering simulation (part 1) in Racket
# Prototypes the state flow
|#
(require net/zmq)

(define (main myself peers)
(printf "Hello, I am ~a\n" myself)
(define ctxt (context 1))

; State Back-End
(define statebe (socket ctxt 'PUB))

; State Front-End
(define statefe (socket ctxt 'SUB))
(set-socket-option! statefe 'SUBSCRIBE #"")

(define bind-address (format "ipc://~a-state.ipc" myself))
(socket-bind! statebe bind-address)
(for ([p (in-list peers)])
(socket-connect! statefe (format "ipc://~a-state.ipc" p)))

(define poller
(vector (make-poll-item statefe 0 'POLLIN empty)))
(let loop ()
(poll! poller 1000000)

(define revents (poll-item-revents (vector-ref poller 0)))
(if (equal? revents '(POLLIN))
(printf "Received: ~a" (socket-recv! statefe))
(socket-send! statebe
(string->bytes/utf-8
(format "~a ~a" bind-address (random 10)))))

(loop))

(context-close! ctxt))

(command-line #:program "peering1"
#:args (myself . peers)
(main myself peers))