New properties API

[robertbastian]

#3573

[robertbastian]

Will fix docs tests after initial review.

[Manishearth]

issue: I'd rather not do this; these types are tagged as unstable in the docs.

Can we instead just use regular integers in the data and convert here? we erase the type anyway

[robertbastian]

I think we should consider them stable instead.

[robertbastian]

The reason I moved them is that they have make_ule, and the ULE types should not be stable.

[Manishearth]

@robertbastian Right, I wish to also consider them stable, which is why I don't want them in the provider module.

Don't worry about make_ule, those are going to go away before 1.0 #5127 . I've been waiting for this PR to land to make that change.

[robertbastian]

https://icu4x-pr-artifacts.storage.googleapis.com/gha/3d38f6a4faa482c01d0d8f146139a628e5ffe9d9/rustdoc/icu/properties/index.html

[Manishearth]

Overall happy with the direction here, mostly have comments on code organization:

• I think the properties should all canonically live in crate::props, not under provider. Don't worry about the ULE types, they're going away
• I think enumerated properties should automatically generate names

Since this is a large PR and unwieldy to review I'm okay merging this with followups.

[Manishearth]

@robertbastian Right, I wish to also consider them stable, which is why I don't want them in the provider module.

Don't worry about make_ule, those are going to go away before 1.0 #5127 . I've been waiting for this PR to land to make that change.

[Manishearth]

Approving with the two code organization bits as followups. I'm happy to do the props one since I want to touch that code anyway.

[robertbastian]

I think enumerated properties should automatically generate names

If you mean merging EnumeratedProperty, NamedEnumeratedProperty and ParseableEnumeratedProperty, that doesn't work because

• Script doesn't use NamedEnumeratedProperty/PropertyNames, it uses ScriptMapper to return icu::locale::subtags::Script
• GeneralCategoryGroup is a pseudo-property, it doesn't implement EnumeratedProperty, but does implement ParseableEnumeratedProperty

[Manishearth]

If you mean merging EnumeratedProperty, NamedEnumeratedProperty and ParseableEnumeratedProperty, that doesn't work because

I meant having the macro generate names too. Not merging the traits.

[Manishearth]

I think the properties should all canonically live in crate::props, not under provider. Don't worry about the ULE types, they're going away

I'll take on this followup

[Manishearth]

Done in #5555. GeneralCategoryULE's macro sticks around since we've not done #5127 yet, but in the longer run we can get rid of it with a macro.