Still going to add docs and changelog and such, just working on getting CI happy in the meantime

One thing I still need to handle are collisions on the name Unknown since that could be a name that someone uses for an enum. Not sure the best thing to do in that case, but leaning toward making our Unknown into $Unknown or something like that. Will create an example and solve it tomorrow.

That's interesting and well-timed as well, I was just thinking of how I'd support open enums in smithy-playground :)

will try to review after the weekend as I'm OOO

but leaning toward making our Unknown into $Unknown or something like that. Will create an example and solve it tomorrow.

I'm happy for you to roll with this 👍

Ultimately decided to render all unknown enum members with a leading $. This simplifies things quite a bit and will make it very clear that the member is coming from an open enum and not from the spec. However, I'm happy to change it to only use a $ when there is a collision if others think that is better.

So apparently using the -Xlint:missing-interpolator option with scala 2.12 means that it will warn on the following:

final case class $Unknown()

So I changed it to be:

final case class $$Unknown()

which works fine, but it is obviously kind of ugly.. so open to other suggestions.

Frankly if it's just 2.12 I would keep the single $ and tell users who are stuck on 2.12 to ignore the warning in the build.

I agree with Jakub

Great work on this ! The only thing that bothers me is the $$ to make 2.12 happy. We can remove this linter from 2.12 and roll with a single $