-- | Returns true if character can appear in identifier.
isIdChar :: Char -> Bool
isIdChar c = isAlphaNum c || (c == '_') || (c == '\'')
isIdChar :: Char -> Bool
isIdChar c = isAlphaNum c || (c == '_') || (c == '\'')
isIdChar c = isAlphaNum c || (c == '_') || (c == '\'')