sanitizeTag :: Text -> Text
sanitizeTag tag | null validGroups = "_"
                | otherwise        = T.intercalate "_" validGroups
    where validGroups = filter (not . T.null) $ T.split (not . isAlphaNum) tag
sanitizeTag :: Text -> Text
sanitizeTag tag | null validGroups = "_"
                | otherwise        = T.intercalate "_" validGroups
    where validGroups = filter (not . T.null) $ T.split (not . isAlphaNum) tag
sanitizeTag tag | null validGroups = "_"
                | otherwise        = T.intercalate "_" validGroups
    where validGroups = filter (not . T.null) $ T.split (not . isAlphaNum) tag