Main.hs

{-# LANGUAGE OverloadedStrings #-}

module Main where

import Control.Monad.Trans
import Network.Wai.Handler.Warp (run)
import Network.Wai
import Network.HTTP.Types (statusOK)
import Data.Enumerator ((>>==), ($$)) 
import qualified Data.Enumerator as E
import qualified Data.ByteString as B
import Blaze.ByteString.Builder (fromByteString)

-- Silly enumerator that gets messages from the keyboard
enum (E.Continue k) = do
  liftIO $ putStrLn "Type a message"
  x <- liftIO B.getLine
  if x == "q"
    then E.continue k
    else k (E.Chunks [fromByteString x]) >>== enum
enum step = E.returnI step

app :: Application
app req = return res

res :: Response
res = ResponseEnumerator resE

resE :: ResponseEnumerator a
resE genIter =
    E.run_ $ enum $$ iter
  where
    iter = genIter statusOK [("Content-Type", "text/event-stream")]

main = run 8000 app