Initial PR demonstrating public API export logic.

[fchollet]

This PR demonstrates how public API export would work:

• There's a decorator that does both public API symbol registration and optional serializable registration (all public API symbols should be serializable, as a general rule).
• There's a build script that uses namex at build time to generate a package that only includes public symbols.

To create the package, simply run python3 build.py instead of python3 -m build. The resulting artifacts can then be collected from dist/ as usual.

TODO: export all public API symbols. Right for we only export one (TransformerEncoder) for demonstration purposes.

[fchollet]

Is there a way to escape the lint error here?

[mattdangerw]

You can add # noqa to the end of the line.

Or maybe # noqa (ignore import lint error) to be a little more readable.

[fchollet]

I updated the PR -- how do you want to proceed? Should we just add the export calls everywhere in this PR and merge? Should we merge first then start a call for contribution to do the conversion? We don't it to have it finished until we do the next PyPI release.

[mattdangerw]

I think we can just move this to requirements.txt

[mattdangerw]

@fchollet when I try to run this naively, e.g.

gh pr checkout 747
pip install namex
python build.py

I get a weird infinite recursion. E.g.

...processing keras_nlp/src/src/src/src/src/src/src/src/src/src/src/src/src/src/src/tokenizers/__init__.py

And eventually a max recursion depth error. Am I doing something wrong in setup?

[mattdangerw]

LGTM!