but some keywords not works (like `#letters` and macroses `@letters` )
The symbol management assumes all languages are C (or if they are not they should be), ie no non-ASCII non-alphanumeric characters like `#` or `@` and as for those _Unicode_ characters!!!! ;-P
parametres whitespace_chars and wordchars
Those don't affect the parsers, they are more to do with selecting words and similar stuff.