feature request: support for Python 3.7 data classes

[anthrotype]

Would it be desirable/feasible to extend cattrs deserialization/serialization support to Python 3.7 Data Classes?
Or is it out of scope?
Thanks for this great little library.

[Tinche]

Definitely something we should look at supporting eventually. And it shouldn't be difficult, since they are basically a subset of attrs.

[petergaultney]

Is this still under consideration? I'd be up for looking into it and seeing if I couldn't make a PR.

[ClaireNeveu]

@Tinche If you're willing to have this functionality I'd be happy to make a PR for it. I have existing code for this that I think would be fairly easy to integrate upstream.

[Tinche]

Sure. I would start by mimicking what the GenConverter does to generate functions for attrs classes, just for dataclasses.

[asford]

@ClaireNeveu did you have a chance to look at your existing code and see if it'd be PR-able?
If you can find the time to open even a super rough draft PR I'd be happy to help tidy it up for testing and merge.
We've just run into this issue and would love to continue using cattrs on some dataclasses-based classes.

[Tinche]

@asford I've put something together over at https://github.com/Tinche/cattrs/tree/tin/dataclasses. Want to try it out and see if it works for you?

[ClaireNeveu]

Ah, I did put something together but I've been pretty sick the past two weeks and haven't found time to PR it.

[asford]

Thanks for the awesome responses.

@ClaireNeveu I hope you can take all the time you need to center on yourself and feel better. For what it's worth, a co-human-you've-probably-never-met-on-the-internet is sending well wishes.

@Tinche looks great so far! I suspected this was going to be pretty doable, but glad to see it's not a massive or disruptive change. The hypothesis-driven tests are a little outside my zone of expertise, so I opened a sub-PR with the basic cases I'm working with. It required a few, minor additional fixes to use the _compat interface that I haven't fully tested.

https://github.com/Tinche/cattrs/pull/134

[Tinche]

Good news, this feature is essentially done! I expect to release it tomorrow.

[Tinche]

Released as 1.4.0.