Extending the purescript-simple-websocket example

Main.purs

module Main where

import Prelude (Unit, return, (==), bind,($))
import Control.Monad (when)
import Control.Monad.Eff (Eff(), runPure)
import Control.Monad.Eff.Class (liftEff)
import Control.Monad.Eff.Var (($=))
import Control.Monad.Eff.Console (log, CONSOLE())
import Data.Maybe (Maybe(..))

import WebSocket (WEBSOCKET, Code(Code), Connection(Connection), Message(Message), Reason(Reason), URL(URL), runMessageEvent, runMessage, newWebSocket)

myConnect :: forall eff. String -> Eff ( ws :: WEBSOCKET, console :: CONSOLE | eff) Connection
myConnect url = do
  connection@(Connection cs) <- newWebSocket (URL url) []
  log "connection opened"
  cs.onopen $= \event -> do
    cs.send (Message "hello")
    log "sent hello message"
    cs.send (Message "goodbye")
    log "sent goodbye message"
  return connection

changeSocketConfig :: forall eff. Eff ( ws :: WEBSOCKET, console :: CONSOLE | eff) Connection -> Eff ( ws :: WEBSOCKET, console :: CONSOLE | eff) String
changeSocketConfig cs = do
  Connection s <- cs
  s.onmessage $= \event -> do
    let received = runMessage (runMessageEvent event)
    when (received == "goodbye") do
      log "connection closing on receipt of goodbye note"
      s.close (Just (Code 1000)) (Just (Reason "none"))
  return "all's well that ends well"

main :: forall e. Eff ( ws :: WEBSOCKET, console :: CONSOLE | e) Unit
main = do
  let cs = myConnect "ws://echo.websocket.org"
  result <-  changeSocketConfig cs
  log result
  log "we're done"

-- | Expected console log in the browser:
-- connection opened
-- all's well that ends well
-- we're done
-- sent hello message
-- sent goodbye message
-- connection closing on receipt of goodbye note