ScottyFib.hs

#!/usr/bin/env stack
-- stack --resolver=lts-13.10 script

{-# LANGUAGE OverloadedStrings #-}

import qualified Data.Text.Lazy                 as TextL
import           Math.NumberTheory.Recurrencies
import           Web.Scotty

main = scotty 8080 $
    get "/fib/:n" $ do
        n <- param "n"
        text $ TextL.pack $ show $ fibonacci n