New scope name for preprocessors

[50Wliu]

Not including prerequisites as they don't apply.

In #188, there was some discussion that entity.name.function.preprocessor.c was not correct. Some alternatives that were proposed, as well as some that I'm proposing right now:

• entity.name.macro.preprocessor.c
• entity.name.identifier.preprocessor.c
• entity.name.expression.preprocessor.c
• entity.name.preprocessor.c
• entity.name.macro.c

None are widely supported by themes, and also have no precedent.

Textmate docs are here, though they don't cover this as well. Proposed Atom naming conventions also doesn't cover this.

cc: @thomasjo @alpyre @simurai @MaximSokolov

[thomasjo]

My votes are, in order of preference;

1. entity.name.identifier.preprocessor.c
2. entity.name.expression.preprocessor.c
3. entity.name.preprocessor.c

[jeff-hykin]

I'm working on maintaining the TextMate grammar for VS Code, so I'd like to coordinate this naming change with you all just to keep theming for both VS Code and Atom somewhat in sync.

I agree there isn't going to be a perfect fix. For most themes I think it is just going to end up being colored with the default color for entity.name.

My vote preference would be for one of

• entity.name.other.preprocessor.macro
• entity.name.identifier.preprocessor.macro

Why other?

I prefer other because several languages (including C++ in other places) could benefit from having entity.name.other. For example, rust, go, php, sass, and r all have non-standard entity.name tags.

• rust has entity.name.lifetime
• go has entity.name.package and entity.name.import
• sass has entity.name.namespace-prefix
  etc

It would be a shame to just pile on another edge case without solving the general case. Even C++ namespaces are not really entity.name.type and should probably be labeled entity.name.other.namespace.

Why preprocessor.macro vs macro.preprocessor or macro?

In general, and in the future, there might be preprocessor entities that are not macros.
Additionally I think:

• entity.name.function.preprocessor should be changed to entity.name.function.macro
• variable.parameter.preprocessor should be changed to variable.parameter.macro

The rust grammar uses entity.name.function.macro so making the above change would also make things slightly more standard.

In the VS Code grammar, macro arguments like ##vars (from #318) are marked as variable.other.macro.argument.cpp .

Why not expression/constant?

Macros can be/do almost anything:

• constants e.g. 10
• variables e.g. test_var
• expressions test_var++
• class names vector<string>
• syntax abbreviations while (true)

Labeling them as expressions/constants would be misleading.

Why not identifier?

entity.name is basically the cross-language word for "identifier that is not a variable". I don't think there is a entity.name that is not an identifier.