Struct tower_lsp::LspServiceBuilder

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pub struct LspServiceBuilder<S> { /* private fields */ }

Expand description

A builder to customize the properties of an LspService.

To construct an LspServiceBuilder, refer to LspService::build.

Implementations§

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impl<S: LanguageServer> LspServiceBuilder<S>

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pub fn custom_method<P, R, F>(self, name: &'static str, callback: F) -> Self
where P: FromParams, R: IntoResponse, F: for<'a> Method<&'a S, P, R> + Clone + Send + Sync + 'static,

Defines a custom JSON-RPC request or notification with the given method name and handler.

§Handler varieties

Fundamentally, any inherent async fn(&self) method defined directly on the language server backend could be considered a valid method handler.

Handlers may optionally include a single params argument. This argument may be of any type that implements Serialize.

Handlers which return () are treated as notifications, while those which return jsonrpc::Result<T> are treated as requests.

Similar to the params argument, the T in the Result<T> return values may be of any type which implements DeserializeOwned. Additionally, this type must be convertible into a serde_json::Value using serde_json::to_value. If this latter constraint is not met, the client will receive a JSON-RPC error response with code -32603 (Internal Error) instead of the expected response.

§Examples

use serde_json::{json, Value};
use tower_lsp::jsonrpc::Result;
use tower_lsp::lsp_types::*;
use tower_lsp::{LanguageServer, LspService};

struct Mock;

// Implementation of `LanguageServer` omitted...

impl Mock {
    async fn request(&self) -> Result<i32> {
        Ok(123)
    }

    async fn request_params(&self, params: Vec<String>) -> Result<Value> {
        Ok(json!({"num_elems":params.len()}))
    }

    async fn notification(&self) {
        // ...
    }

    async fn notification_params(&self, params: Value) {
        // ...
    }
}

let (service, socket) = LspService::build(|_| Mock)
    .custom_method("custom/request", Mock::request)
    .custom_method("custom/requestParams", Mock::request_params)
    .custom_method("custom/notification", Mock::notification)
    .custom_method("custom/notificationParams", Mock::notification_params)
    .finish();