create schema for `CAPI2` core format

It would be nice to have a schema for defining constraint of the fields defining the CAPI2 core format.

Related: https://github.com/olofk/edalize/issues/288

[GlenNicholls]

I tried for a while to mess with dataclasses for config files and they’re pretty annoying because you have to implement all the validation/transformations in a more verbose way than pydantic. Not only this, but serializing config files isn’t as easy as this with dataclass like pydantic supports:

class Something(BaseModel):
    ...

with open("cfg.file") as f:
  yml = serial blah stuff
data = Something(**yml)

It looks like datamodel-code-generator can generate pydantic models directly from JSON schema to actually validate core files at runtime. I’m not sure how good datamodel-code-generator is, but IMO, I think starting with pydantic basemodel as your code is already python makes sense because you can just export the model to JSON for anyone who wants the schema. I believe that pydantic also has a dataclass identical to the standard lib capable of validation as well.

EDIT: just wanted to provide some ideas as I spent more time than I’d like to admit to test different tools to figure out how to validate config files, document extensively how to write them for users, and also provide extensive documentation about the actual code that parses for devs.

[proppy]

Yep, this and dataclasses also got mentioned in https://github.com/olofk/edalize/issues/288.

That would be a good way to piggy back on the existing python tooling for doc generation.