add gen_lsp_server

1 files changed, 77 insertions, 0 deletions

diff --git a/crates/gen_lsp_server/src/lib.rs b/crates/gen_lsp_server/src/lib.rs
new file mode 100644
index 000000000..a31e90f35
--- /dev/null
+++ b/crates/gen_lsp_server/src/lib.rs
@@ -0,0 +1,77 @@
+#[macro_use]
+extern crate failure;
+#[macro_use]
+extern crate log;
+extern crate serde;
+extern crate serde_json;
+#[macro_use]
+extern crate serde_derive;
+extern crate crossbeam_channel;
+extern crate languageserver_types;
+
+mod msg;
+mod stdio;
+
+use crossbeam_channel::{Sender, Receiver};
+use languageserver_types::{
+    ServerCapabilities, InitializeResult,
+    request::{Initialize},
+    notification::{Initialized, Exit},
+};
+
+pub type Result<T> = ::std::result::Result<T, failure::Error>;
+pub use {
+    msg::{RawMessage, RawRequest, RawResponse, RawResponseError, RawNotification},
+    stdio::{stdio_transport, Threads},
+};
+
+pub type LspServer = fn(&mut Receiver<RawMessage>, &mut Sender<RawMessage>) -> Result<()>;
+
+pub fn run_server(
+    caps: ServerCapabilities,
+    server: LspServer,
+    mut receiver: Receiver<RawMessage>,
+    mut sender: Sender<RawMessage>,
+) -> Result<()> {
+    info!("lsp server initializes");
+    initialize(&mut receiver, &mut sender, caps)?;
+    info!("lsp server initialized, serving requests");
+    server(&mut receiver, &mut sender)?;
+    info!("lsp server waiting for exit notification");
+    match receiver.recv() {
+        Some(RawMessage::Notification(n)) => {
+            n.cast::<Exit>().map_err(|n| format_err!(
+                "unexpected notification during shutdown: {:?}", n
+            ))?
+        }
+        m => bail!("unexpected message during shutdown: {:?}", m)
+    }
+    info!("lsp server shutdown complete");
+    Ok(())
+}
+
+fn initialize(
+    receiver: &mut Receiver<RawMessage>,
+    sender: &mut Sender<RawMessage>,
+    caps: ServerCapabilities,
+) -> Result<()> {
+    let id = match receiver.recv() {
+        Some(RawMessage::Request(req)) => match req.cast::<Initialize>() {
+            Err(req) => bail!("expected initialize request, got {:?}", req),
+            Ok(req) => req.0,
+        }
+        msg =>
+            bail!("expected initialize request, got {:?}", msg),
+    };
+    let resp = RawResponse::ok(id, InitializeResult { capabilities: caps });
+    sender.send(RawMessage::Response(resp));
+    match receiver.recv() {
+        Some(RawMessage::Notification(n)) => {
+            n.cast::<Initialized>().map_err(|_| format_err!(
+                "expected initialized notification"
+            ))?;
+        }
+        _ => bail!("expected initialized notification"),
+    }
+    Ok(())
+}