tower-lsp
Language Server Protocol implementation for Rust based on Tower.
Tower is a simple and composable framework for implementing asynchronous
services in Rust. Central to Tower is the Service
trait, which provides the
necessary abstractions for defining request/response clients and servers.
Examples of protocols implemented using the Service
trait include
tower-web
and tower-grpc
.
This library (tower-lsp
) provides a simple implementation of the Language
Server Protocol (LSP) that makes it easy to write your own language server. It
consists of three parts:
- The
LanguageServer
trait, which defines the behavior of your language server.
- The asynchronous
LspService
delegate, which wraps your language server
implementation and defines the behavior of the protocol.
- A
Server
which spawns the LspService
and processes requests and responses
over stdin and stdout.
Example
use futures::future;
use jsonrpc_core::{BoxFuture, Result};
use tower_lsp::lsp_types::*;
use tower_lsp::{LanguageServer, LspService, Printer, Server};
#[derive(Debug, Default)]
struct Backend;
impl LanguageServer for Backend {
type ShutdownFuture = BoxFuture<()>;
type HighlightFuture = BoxFuture<Option<Vec<DocumentHighlight>>>;
type HoverFuture = BoxFuture<Option<Hover>>;
fn initialize(&self, _: InitializeParams) -> Result<InitializeResult> {
Ok(InitializeResult::default())
}
fn initialized(&self, printer: &Printer, _: InitializedParams) {
printer.log_message(MessageType::Info, "server initialized!");
}
fn shutdown(&self) -> Self::ShutdownFuture {
Box::new(future::ok(()))
}
fn did_open(&self, printer: &Printer, _: DidOpenTextDocumentParams) {
printer.log_message(MessageType::Info, "file opened!");
}
fn did_change(&self, printer: &Printer, _: DidChangeTextDocumentParams) {
printer.log_message(MessageType::Info, "file changed!");
}
fn did_save(&self, printer: &Printer, _: DidSaveTextDocumentParams) {
printer.log_message(MessageType::Info, "file saved!");
}
fn did_close(&self, printer: &Printer, _: DidCloseTextDocumentParams) {
printer.log_message(MessageType::Info, "file closed!");
}
fn hover(&self, _: TextDocumentPositionParams) -> Self::HoverFuture {
Box::new(future::ok(None))
}
fn highlight(&self, _: TextDocumentPositionParams) -> Self::HighlightFuture {
Box::new(future::ok(None))
}
}
fn main() {
let stdin = tokio::io::stdin();
let stdout = tokio::io::stdout();
let (service, messages) = LspService::new(Backend::default());
let handle = service.close_handle();
let server = Server::new(stdin, stdout)
.interleave(messages)
.serve(service);
tokio::run(handle.run_until_exit(server));
}
License
tower-lsp
is free and open source software distributed under the terms of
both the MIT and the Apache 2.0 licenses.
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.