Add argparse to pygemnts2chroma_xml.py script

[flofriday]

I also adapted the README to use uv since this removes an install step (uv resolves and installs dependencies on uv run).

We could also debate if we should switch from KotlinLexer as an example to some other lexer as there seems to be a bug upstream in pygments where KotlinLexer.get_tokendefs() returns a string that is not valid unicode. You can read more about the bug in this issue.

With argparse the error messages are a lot nicer and the script can better explain itself.

uv run pygments2chroma_xml.py --help                         
usage: pygments2chroma_xml.py [-h] lexer_class

Converts pygments RegexLexer classes to chroma xml grammar definitions.

positional arguments:
  lexer_class  The class name of the pygments lexer, like: 'pygments.lexers.jvm.KotlinLexer'.

options:
  -h, --help   show this help message and exit

[alecthomas]

This change and the .. below seem unnecessary...

[alecthomas]

Also the script is executable, you can actually just run ./_tools/pygments2chroma_xml.py

Want to run this too?

uv add --script ./_tools/pygments2chroma_xml.py pystache pygments

As the script currently doesn't have the dependencies embedded, it won't automatically download them or create a venv.

[flofriday]

Yes that makes more sense.
Do we still need the _tools/pyprojects.toml file then?

[alecthomas]

Ah, no!