Consistent highlight on derives' qualIds

[tanishiking]

fix: https://github.com/scala/vscode-scala-syntax/issues/239

vscode-scala-syntax couldn't provide consistent highlights for C and D in derives C, D.

Problem

Consider we have the following code

enum A extends B derives C, D

Previously, B and C have the following TextMate Scopes

entity.other.inherited-class.scala
source.scala

while D has

entity.name.class
source.scala

because it had accepted only one qualId after derived https://github.com/scala/vscode-scala-syntax/blob/0b2b1e8829254f0d190e723d3a49874cb7d135c0/src/typescript/Scala.tmLanguage.ts#L1156 even though Scala3 syntax allows us to put multiple qualIds.

Therefore, the first one will have entity.other.inherited-class.scala, but the following qualIds won't be named as entity.other.inherited-class.scala. Instead, falllback to entity.name.class based on it's name (upper camel).

fix

This commit makes it provides consistent highlight for each qualId after derives keyword. Now, both C and D will have entity.name.class instead of entity.other.inherited-class.scala.

alternative solution

It would be ideal to put entity.other.inherited-class.scala to both C and D, but it looks like impossible with TextMate grammar. Because according to the syntax (see the syntax spec for Scala3 here https://docs.scala-lang.org/scala3/reference/syntax.html) we can't tell where's the end of derives clause.

In the complete program, we can tell { or : is the end of derives clause, but it messes up if the program is incomplete like

enum A extends B derives C, D

where there's no : or {.

So, just give up providing entity.other.inherited-class.scala and put entity.name.class based on their name (upper camel).

[tanishiking]

@Meowcolm024 What do you think about this? you can check it by

• check out this branch tanishiking:derives
• yarn install, yarn build
• code --install-extension scala-0.5.6.vsix
• restart vscode

[tanishiking]

Decided to assign entity.name.class to A, B in extends A, B, maybe we should do the same thing for with A (even though it doesn't accept with A, B) for consistency 🤔

[tanishiking]

Closing for https://github.com/scala/vscode-scala-syntax/pull/242