VS Code Semantic highlighting does not highlight async/await keywords

[adam-fowler]

Moved this from server thread Introducing Swift for Visual Studio Code

@taylorswift

the async and await contextual keywords don’t receive syntax highlighting, apparently because the semantic highlighter classifies them as identifiers, and as far as i can tell, it is not possible to override a semantic highlight with a textmate highlight (which correctly detects it as a keyword.)

is there a fix?

@taylorswift

@adam-fowler

What version of vscode are you running? The highlighting is done VS Code. This is the code in here vscode/swift.tmLanguage.json at main · microsoft/vscode · GitHub

the highlighting is not done by VSCode, it is done by sourcekitd. this is the issue i was alluding to earlier in this thread.

the reason you are seeing a colored await is likely because you have the syntax highlighting turned off, in your settings.json, or whatever VSCode theme you are using. because the highlighter is disabled, the editor attempts to apply the heuristics in swift.tmLanguage.json instead, which knows how to highlight await but is less accurate elsewhere.

i've observed a similar problem with #if, #else and friends, but because the VSCode swift extension doesn’t attempt to label them (whereas it labels await as an identifier), it is possible to provide a fallback for those in a way that is not possible for await and async, and probably override and the other contextual keywords as well.

(note: i don’t know why the preprocessor macros don’t get highlights, these labels exist in sourcekitd, and Atomic Blonde was always able to access them, so my guess is the VSCode extension is just discarding them.)

[adam-fowler]

The Swift VS Code extension does nothing with the semantic highlighting. All the extension does is start a SourceKit-LSP server and point at the workspace folder. The LSP server then communicates directly with VS Code bypassing the extension. If the async, await and #if etc symbols are not being highlighted correctly I would imagine it is SourceKit-LSP's implementation of semantic highlighting that has the errors. It can't be the extension as it isn't part of the equation by this point and I doubt it is VS Code as LSP was originally developed for VS Code.

I'll investigate a little more to see if I can narrow this down.