languageTag :: CharParser st String
languageTag = atMost1 4 letter
  <++> flat (many $ char '-' <:> atMost1 8 alphaNum)
languageTag :: CharParser st String
languageTag = atMost1 4 letter
  <++> flat (many $ char '-' <:> atMost1 8 alphaNum)
languageTag = atMost1 4 letter
  <++> flat (many $ char '-' <:> atMost1 8 alphaNum)