如何在Options.Applicative中编写互斥标志的代码

import Options.Applicative

data Options = Options
  { flag1 :: Bool
  , flag2 :: Bool
  } deriving Show

optionsParser :: Parser Options
optionsParser = Options
  <$> switch (long "flag1" <> help "Enable flag 1")
  <*> switch (long "flag2" <> help "Enable flag 2")

main :: IO ()
main = do
  opts <- execParser (info (optionsParser <**> helper) idm)
  print opts

optionsParser :: Parser Options
optionsParser = Options
  <$> (switch (long "flag1" <> help "Enable flag 1") <|> pure False)
  <*> (switch (long "flag2" <> help "Enable flag 2") <|> pure False)