Why are module names not properly highlighted?

[bzm3r]

I am using the VS Code extension to integrate HLS.

I import a module called Bird1, and in the picture below, we can see textmate scopes being picked up but no semantic token type:

Similarly, when I hover over the usage of Bird1 in the file, it gets picked up as a variable instead of a module:

Note that a name following a module token is also not recognized by the semantic highlighter:

It seems to me that the requisite functionality does exist:

haskell-language-server/plugins/hls-semantic-tokens-plugin/src/Ide/Plugin/SemanticTokens/Types.hs

Line 43 in 0047d13

| TModule -- module name

Am I right in understand that? So, there's something missing from the VS Code Extension's end? (I think if I am right in understanding the issue, then there I know what to do to fix it in the VS Code extension.)

(I am also happy to contribute fixes to HLS, if necessary! Some guidance on where I might want to start looking would be helpful.)

[soulomoon]

Which version are you using, module name splitting out is only available in the master head.

we currently have

[bzm3r]

Ah, I am not using the master version! Okay, I think that explains the issue.

[michaelpj]

@soulomoon did you also do highlighting of the module name in module X where?

[soulomoon]

No, it seems does not appear in the hieAst where we get our identifiers

[michaelpj]

Maybe we should make a ticket for that. It's not very important, but it will make things look a little inconsistent I guess.

[soulomoon]

agree

[soulomoon]

I also observed some inconsistent with applicativedo, since it modifies the ast during the transition parsedSource -> typecheckSource.
I am actually considering about using the parsedSource for names and modules and collect whatever we can in occname first.
Then combine this with the hieAst to create semantic tokens. (similar proccess is happening in the rust analyzor if i am not mistaken, but they have their lossless syntax trees rowan).

This way we have some advantages.

1. Even if the file fail to typecheck for some reason, we might still be able to have some highlighting.
2. Avoid some breaks introduced by extension like applicativedo.

[soulomoon]

@michaelpj I have created an issue for the missing module name in module x where in ghc https://gitlab.haskell.org/ghc/ghc/-/issues/24493

[soulomoon]

Also proposed a PR in ghc to fix that https://gitlab.haskell.org/ghc/ghc/-/merge_requests/12153