exception str() failed in `UnexpectedCharacters` because of 'PatternRE' has no attribute 'raw'

[NiklasRosenstein]

Describe the bug

Lark v1.1.2

The standalone parser generated with python -m lark.tools.standalone appears to have an issue with the PatternRE/PatternStr subclasses because when I get an UnexpectedCharacters error, it's exception formatting fails because of

kraken.lang._generated_parser.UnexpectedCharactersTraceback (most recent call last):
  File ".venvs/3.9/lib/python3.9/site-packages/kraken/lang/_generated_parser.py", line 206, in __str__
    message += self._format_expected(self.allowed)
  File ".venvs/3.9/lib/python3.9/site-packages/kraken/lang/_generated_parser.py", line 143, in _format_expected
    expected = [d[t_name].user_repr() if t_name in d else t_name for t_name in expected]
  File ".venvs/3.9/lib/python3.9/site-packages/kraken/lang/_generated_parser.py", line 143, in <listcomp>
    expected = [d[t_name].user_repr() if t_name in d else t_name for t_name in expected]
  File ".venvs/3.9/lib/python3.9/site-packages/kraken/lang/_generated_parser.py", line 1187, in user_repr
    return self.pattern.raw or self.name
AttributeError: 'PatternRE' object has no attribute 'raw'

To Reproduce

• Take some Lark grammar
• Generate a standalone parser
• Feed it some input that results in an UnexpectedCharacters error

If it helps, I attached the standalone parser that was generated on my side:

_generated_parser.py.zip