Convert tags to a SetField

[brimoor]

It would be preferable for tags to be represented as sets in Python land. See below for discussion.

Also, this would be a convenient time to create our own wrappers around MongoEngine fields so that our user interface is decoupled from MongoEngine classes:

[tylerganter]

I made a PR into MongoEngine. We shall see how it goes

MongoEngine/mongoengine#2337

[brimoor]

Can we support this directly in FiftyOne for the time being? It could internally use MongoEngine's ListField and just convert to sets at the object-level.

I have a suspicion that it won't be easy to get your PR into MongoEngine, and even then it will take time to get this into an official release so that pip-installable FiftyOne can use it

[tylerganter]

The core reason that I did this in MongoEngine and not fiftyone is that there needs to be a notion of a BaseSet that watches modifying operations and notifies MongoEngine. If we go the route of supporting this just with 51, which we could, we'd have to change the interface for tags, similar to this add_tag and remove_tag idea which would break from the behavior of all other fields.

Can the user no longer access the sample.tags? Only sample.get_tags()?

I am working on database synchronization right now. I can keep this in the back of my mind while I do that since it is all related.

[brimoor]

Hmm sounds like this issue will likely have to go into hibernation then. No easy path forward, and it's not THAT big of an inconvenience to use lists

[tylerganter]

I'll keep an eye on this issue. But the easy alternatives don't seem much better than leaving it as a list