Update Rust to match CLion

[bernardoamorim7]

Hi, Rust isn't currently similar to CLion's implementation because of semantic highlighting being off.
To fix this issue I added this in the settings, I don't know if it is possible to implement this directly in the extension:

    "[rust]": {
        "editor.semanticHighlighting.enabled": true,
    },
    "editor.semanticTokenColorCustomizations": {
        "[JetBrains Darcula Theme]": {
            "rules": {
                "*.attribute": {
                    "foreground": "#BBB529"
                },
                "lifetime": {
                    "foreground": "#20999D"
                },
                "typeParameter": {
                    "foreground": "#20999D"
                },
                "*.mutable": {
                    "foreground": "#BCA5C4",
                    "underline": true,
                },
                "macro": {
                    "foreground": "#4EADE5"
                },
                "macroBang": {
                    "foreground": "#4EADE5"
                },
                "enumMember": {
                    "foreground": "#9876AA"
                },
                "*.constant": {
                    "foreground": "#9876AA"
                },
                "string": {
                    "foreground": "#6A8759"
                },
            }
        },
    }

This is the closest I could get, I can't find a way to change struct field's color. In CLion it's under Variables>Field.
println! is a macro for example and only the ! will turn blue.

[Jan Gazda]

@bernardoamorim7 Thank you so much for this, I just started with rust and this was driving me crazy, since I know nearly nothing about VSCode customisation.

[bernardoamorim7]

@1oglop1 You can also add this, I found it a bit after:

    "unresolvedReference": {
      "foreground": "#9876AA"
    },
    "operator": {
      "foreground": "#abb2bf"
    },

It looks a bit nicer with this, although in a big codebase, for some reason, there are a lot of unresolved references adn there will lots of purple, maybe it's a rust-analyzer thing.
Check the pr that I made #10 it adds non semantic highlighting support aswell.

[Anan]

Semantic Highlighting is not activated by default in this theme because It's so tricky to deal with and it's "an addition to syntax highlighting" You can take a look at how it works here

Highlighting based on semantic tokens is considered an addition to the TextMate-based syntax highlighting. Semantic highlighting goes on top of the syntax highlighting. And as language servers can take a while to load and analyze a project, semantic token highlighting may appear after a short delay.

---

Enablement of semantic highlighting

By default Semantic Highlighting value is false in this theme, you can add this snippet in your "settings.json" file to disable it:

"editor.semanticHighlighting.enabled": true

Please check the official documentation,
Theme Color Reference and Theme Color, for more helpful information.
More info

---

So If you want to enable it, you have to customize every class, parameter, function,..etc colors for each language as you did in the snippet you provide

[bernardoamorim7]

Yeah I figured that out, same token names means there would be conflicts between languages, thats why I made the pr without it, looks good still. The tweaks I provided can be added my anyone who wants it in their personal settings.

[Anan]

Thank you merged! #10