Failed URI Hello World

failed_hello.hs

{-# LANGUAGE OverloadedStrings #-}
module Main where

import           Control.Applicative
import           Snap.Core
import           Snap.Util.FileServe
import           Snap.Http.Server
import           Data.Text (Text)
import           Data.Text.Encoding(encodeUtf8)

main :: IO ()
main = quickHttpServe site

site :: Snap ()
site =
    ifTop (writeBS "hello world") <|>
    route [ ("foo", writeBS "bar")
          , ("echo", pathArg echoHandler)
          ] <|>
    dir "static" (serveDirectory ".")

echoHandler :: Text -> Snap ()
echoHandler name = do
    writeBS $ encodeUtf8 name