[Bug] Syntax highlighting of user-defined types in parameters are broken

[alihakankurt]

When the following Tree-sitter query is active in highlights.scm for C# (at line 226 currently):

(parameter (identifier) @variable)

it causes user-defined parameter types to lose their type highlighting. Instead, both the parameter name and the type are highlighted as variables. This breaks the expected syntax highlighting for user-defined types in method signatures.

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Current behaviour:

Expected behaviour (when mentioned Tree-sitter query line commented out):

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Environment:

• Zed Version: 0.209.6
• C# Extension Version: 0.1.3
• OS: macOS Tahoe 26

[recore67]

This is unrelated, but I'd like to suggest for having a distinct color on parameter variables so that it's easier to distinguish them from global variables. if you take a look at X and the parameter x for example, they both share the same color.

[alihakankurt]

This is unrelated, but I'd like to suggest for having a distinct color on parameter variables so that it's easier to distinguish them from global variables. if you take a look at X and the parameter x for example, they both share the same color.

This is a feature that I also want for a while. It's mostly related to the themes rather than the language grammers because Zed's theme template does not have many tags. If we have a tag named parameter, it could be easy to configure for a different color. An example for this from Catppuccin Theme, there is a tag named variable.parameter in the theme file if you take a look. When we update the parameter query like this:

;; Parameter
(parameter
    name: (identifier) @variable.parameter)
(parameter_modifier) @keyword

it can make parameter color different, but it's not a standard tag. We could also have tags like interface, struct to have different colors from class. And the main reason we can't have these specialized tags is that Zed themes are based on Rust, and they are not very comprehensive for other languages.