Pub-Sub envelope subscriber in F#

Pubsub envelope subscriber

#r @"bin/fszmq.dll"
open fszmq
open fszmq.Context
open fszmq.Socket

#load "zhelpers.fs"
let main () =
// prepare our context and publisher
use context = new Context(1)
use subscriber = sub context
"tcp://localhost:5563" |> connect subscriber
[ "B"B ] |> subscribe subscriber

while true do
// read envelope with address
let address = s_recv subscriber
// read message contents
let contents = s_recv subscriber
printfn "[%s] %s" address contents

// we never get here but clean up anyhow

main ()