Configuring Semantic Tokens

To configure semantic tokens, you need to use the define_semantic_token_types and define_semantic_token_modifiers macros.

Token Types

use auto_lsp::define_semantic_token_types;

define_semantic_token_types![
    standard {
         "namespace" => NAMESPACE,
         "type" => TYPE,
         "function" => FUNCTION,
    }
    
    custom {
        "custom" => CUSTOM,
    }
];

This macro generates three components to streamline working with semantic token types:

1. Constants: Creates a constant for each standard and custom token type.
2. Supported Token Types: Generates a slice (SUPPORTED_TYPES) containing all supported token types that can be reused to inform the LSP client about available tokens.

Token Modifiers

use auto_lsp::define_semantic_token_modifiers;
define_semantic_token_modifiers![
    standard {
        DOCUMENTATION,
        DECLARATION,
    }

    custom {
        (READONLY, "readonly"),
        (STATIC, "static"),
    }
];

This generates:

• Constants for standard (DOCUMENTATION, DECLARATION) and custom (READONLY, STATIC) modifiers.
• A SUPPORTED_MODIFIERS slice that includes both standard and custom modifiers.

Example in AST

use auto_lsp::semantic_tokens::{SemanticToken, SemanticTokenType, SemanticTokenModifier};

define_semantic_token_types![
    standard {
        FUNCTION,
    }

    custom {}
];

define_semantic_token_modifiers![
    standard {
        DECLARATION,
    }

    custom {}
];

impl BuildSemanticTokens for MyType {
    fn build_semantic_tokens(&self, doc: &Document, builder: &mut SemanticTokensBuilder) {
        builder.push(
            self.name.read().get_lsp_range(doc),
            SUPPORTED_TYPES.iter().position(|x| *x == FUNCTION).unwrap() as u32,
            SUPPORTED_MODIFIERS.iter().position(|x| *x == DECLARATION).unwrap() as u32,
        );
    }
}

LSP Server Initialization

To inform the LSP client about the supported token types and modifiers, you need to pass the SemanticTokensList to the LspOptions struct.

fn main() -> Result<(), Box<dyn Error + Sync + Send>> {
    let mut session = Session::create(InitOptions {
        parsers: &PYTHON_PARSERS,
        lsp_options: LspOptions {
            semantic_tokens: Some(SemanticTokensList {
                semantic_token_types: SUPPORTED_TYPES,
                semantic_token_modifiers: SUPPORTED_MODIFIERS,
            })
            ..Default::default()
        },
    })?;
}