Cache in C PEG-generator reworked:
we save artificial rules in cache by Node string representation as a key instead of Node object itself.
As a result total count of artificial rules in parsers.c is lowered from 283 to 170.
More natural number ordering is used for the names of artificial rules.
Auxiliary method CCallMakerVisitor._generate_artificial_rule_call is added.
Its purpose is abstracting work with artificial rules cache.
Explicit using of "is_repeat1" kwarg is added to visit_Repeat0 and visit_Repeat1 methods.
Its slightly improve code readabitily.
This is for the C generator:
- Disallow rule and variable names starting with `_`
- Rename most local variable names generated by the parser to start with `_`
Exceptions:
- Renaming `p` to `_p` will be a separate PR
- There are still some names that might clash, e.g.
- anything starting with `Py`
- C reserved words (`if` etc.)
- Macros like `EXTRA` and `CHECK`
