gh-113317: Add libclinic.block_parser and libclinic.language modules

[vstinner]

• Move Block and BlockParser classes to a new libclinic.block_parser module.
• Move Language and PythonLanguage classes to a new libclinic.language module.

• Issue: Argument Clinic: split out global stateless helpers and constants from clinic.py #113317

[erlend-aasland]

Would it not be better to create a libclinic.parser and put all parser-related stuff there? Do we need the libclinic.block_parser granularity?

[erlend-aasland]

Instead of libclinic.language, would it not be better to split things up in the kind of language? For example:

• libclinic.lang_c for C language render data and the CLanguage class
• libclinic.lang_python for the PythonLanguage class and its helpers

Now, we suddenly have C language stuff scattered over two submodules: libclinic.language and libclinic.crenderdata.

[erlend-aasland]

Should Block and BlockParser belong to the same submodule? What about BlockPrinter? What was the rationale of putting Block in the libclinic.block_parser submodule?

[vstinner]

What was the rationale of putting Block in the libclinic.block_parser submodule?

I started with very small files to break inter-dependencies, otherwise it's not possible to move any line of code.

Once more more will live in libclinic, it will be easier to move related code together.

CLanguage should live in its on own file, right.

[vstinner]

Should Block and BlockParser belong to the same submodule?

BlockParser creates Block, so they are related, no?

What about BlockPrinter?

I didn't manage to move it yet. But I would prefer to separate parsing code and code genereration code in different files, if possible.

[erlend-aasland]

[...] I would prefer to separate parsing code and code genereration code in different files, if possible.

Yes, this is something we've been discussing. How about putting the intermediate representation (Block) in its own file? After all, it is shared between the parser and the generator. This is why we should discuss changes before merging.