Do we want the string alias to be User-defined verbatim, with hyphen and lowercase "defined"? I think that's most consistent with the usage elsewhere in the schema.

Apologies, my description is inconsistent with the code I wrote! In the code, the alias is "User defined". I've updated the description to match the code.

EDIT: I also need to add the hyphen. Will update.

Yeah, I think the hyphen is required - it's pedantic to say so but that is kind of the point!

@rtimms One issue that occurred to me that I haven't been able to test, but perhaps you could.

I wasn't sure from your latest type-fixing commit - do we allow an arbitrary nested structure in the JSON under "User-defined". It feels like we should - that is, we shouldn't care if there is extra JSON hierarchy within this zone.

Would treating all dict as InterpolatedTable break this?

We do not currently allow this kind of structure. Everything in "User-defined" must be of the type FloatFunctionTable. I'm reaching the limit of my pydantic knowledge now, but what you are suggesting should be possible. I'll give it a try, but may need to call in reinforcements!

@rtimms Happy to save that for a future update if necessary. Besides anything else, we would need to more carefully define what is and is not an InterpolatedTable.

@ejfdickinson, let's leave the careful definition of what is and is not an InterpolatedTable for a future issue. Otherwise, does this PR look ok to you?

@rtimms Yes, if the tests are passing including the example I generated, that's fine. Can you make a new issue for supporting arbitrary JSON hierarchy under User-defined?

Thanks, new issue is here #46

Can you hit "approve" so this can be merged?