{-# LANGUAGE OverloadedStrings #-}
import Control.Applicative
import Data.Monoid
import Data.String
import Network.Wai.Middleware.RequestLogger
import Web.Scotty
data FullName = FullName { firstName :: String, lastName :: String }
lastFirst :: FullName -> String
lastFirst fn = lastName fn ++ ", " ++ firstName fn
main = scotty 3000 $ do
middleware logStdoutDev
get "/lastfirst/:fn/:ln" $ do
fullName <- FullName <$> param "fn" <*> param "ln"
html $ fromString (lastFirst fullName)
您可能注意到代码的最后一部分使用应用函数来构造记录,有人可以解释为什么不应该像往常一样创建它吗?