lazy_instance and dataclasses ?

[cgebbe]

🚀 Feature request

Thanks for this awesome library! I would like the following simple example to work:

import jsonargparse
from dataclasses import dataclass

@dataclass
class Bar:
    x: int

bar=jsonargparse.lazy_instance(Bar, x=3)
bar.x

Motivation

I really like lazy_instance: Its much nicer than writing long, nested YAML files, but still translates into a nice config Namespace which can be easily reused. However, currently, dataclasses don't seem to be really supported

[mauvilsa]

Thank you for proposing improvements!

Could you please clarify a bit? lazy_instance is not intended to be used alone (like above), but only to avoid actual instance defaults in signatures. Also, lazy_instance doesn't return a Namespace, so I am a bit confused by the motivation or how that relates to YAML files.

I do see that lazy_instance is not working for dataclasses, but I am not sure there is a need for it.