Tatsu

* Now ``config: ParserConfig`` is used in ``__init__()`` and ``parse()`` methods of ``contexts.ParseContext``, ``grammars.Grammar``, and elsewhere to avoid the very long parameter lists that abounded. ``ParseContext`` also provides clean and clear ways of overridinga group of settings with another
* All names defined in the successful choice in a rule are now defined in the resulting `AST`_. Names within optionals that did not match will have their values set to ``None``, and closures that did not match will be set to ``[]`
* Moved build configuration from ``setup.py`` in favor of ``setup.cfg`` and ``pyproject.toml`` (`KOLANICH`_)
* ``Node.children()`` is now computed only when required, and cached
* Classes in generated object models are now ``dataclass``
* Optimize and get rid of bugs and annoyances while keeping backwards compatibility
* Drop support for Python < 3.10

* Fix bug in which rule fields were forced on empty ``AST`` (Victorious3)

* Several important refactorings in ``contexts.ParseContext``
* Make ``ignorecase`` settings apply to defined ``keywords``
* Move checking of keywords used as names into ``ParseContext``
* Output of generated parsers again matches that of model parsers
* Improve *"expecting one of:"* messages so elements are in declaration order
* Stop code generation if there are closures over possibly empty expressions
* Preserve name declaration order in returned ``AST``
* Update the bootstrap parser (``tatsu/bootstrap.py``) to the generated parser
* Now generated parser's ``main()`` only outputs the JSON for the parse ``AST``
* Minor version bumped in case the many fixes break backwards-compatibility
* Minor documentation issues fixed
* All tests run with Python 3.8, 3.9, 3.10

* 156 Clarify limitations of left-recursion in PEG (apalala).
* 159 Clean up examples and tutorial, upgrade them to Python 3 (okomarov).
* Test with Python 3.9 (apalala)
* Update CircleCI build (apalala)

- 竜 **TatSu** is now only tested against Python 3.8. Earlier versions of Python are now deprecated, and Python 2.X versions are no longer supported ([apalala](https://github.com/apalala)).
- Apply `nameguard` only if `token[0].isalpha()`. This solves a regression afecting previous TatSu and Grako grammars ([apalala](https://github.com/apalala)).
- Remove `pygraphviz` from develoment requirements, as it doesn't build under Py38 ([apalala](https://github.com/apalala))
- [\56](https://github.com/neogeny/TatSu/issues/56) Include missing `tatsu/g2e/antlr.ebnf` in distribution ([apalala](https://github.com/apalala))
- [\138](https://github.com/neogeny/TatSu/issues/138) Reimplement the calculation of `FIRST`, `FOLLOW`, and `LOOKAHEAD` sets using latest theories. For now, this should improve parser error reporting, but should eventually enable the simplification of parsing of leftrec grammars ([apalala](https://github.com/apalala)).
- [\153](https://github.com/neogeny/TatSu/issues/153) Import ABCs from `collections.abc` ([tirkarthi](https://github.com/tirkarthi))
- Remove support for ``Cython``and ``pypy3`` ([apalala](https://github.com/apalala)).

- The default regexp for whitespace was changed to \`<span class="title-ref">(?s)s+</span>
- Allow empty patterns (`//`) like Python does
- [\65](https://github.com/neogeny/TatSu/issues/65) Allow initial, consecutive, and trailing `namechars`
- [\73](https://github.com/neogeny/TatSu/issues/73) Allow `whitespace :: None` and `whitespace :: False`
- [\75](https://github.com/neogeny/TatSu/issues/75) Complete implemenation of left recursion([Victorious3](https://github.com/Victorious3))
- [\77](https://github.com/neogeny/TatSu/issues/77) Allow `keyword` throughout the grammar
- [\89](https://github.com/neogeny/TatSu/issues/89) Make all attributes defined in the rule present in the resulting `AST` or `Node` even if the associated expression was not parsed
- [\93](https://github.com/neogeny/TatSu/issues/93) Fix trace colorization on Windows
- [\96](https://github.com/neogeny/TatSu/issues/96) Documented each `directive`
- Switched the documentation to the "Alabaster" theme
- Various code and documentation fixes ([davesque](https://github.com/davesque), [nicholasbishop](https://github.com/nicholasbishop), [rayjolt](https://github.com/rayjolt))