3 files changed, 79 insertions, 77 deletions

diff --git a/crates/server/src/dispatch.rs b/crates/server/src/dispatch.rs
index eb23ab64f..369c56b64 100644
--- a/crates/server/src/dispatch.rs
+++ b/crates/server/src/dispatch.rs
@@ -19,38 +19,27 @@ pub struct Responder<R: ClientRequest> {
     ph: PhantomData<fn(R)>,
 }
 
-impl<R: ClientRequest> Responder<R>
-{
-    pub fn response(self, io: &mut Io, resp: Result<R::Result>) -> Result<()> {
-        match resp {
-            Ok(res) => self.result(io, res)?,
-            Err(e) => {
-                self.error(io)?;
-                return Err(e);
-            }
-        }
-        Ok(())
-    }
-
-    pub fn result(mut self, io: &mut Io, result: R::Result) -> Result<()> {
+impl<R: ClientRequest> Responder<R> {
+    pub fn into_response(mut self, result: Result<R::Result>) -> Result<RawResponse> {
         self.bomb.defuse();
-        io.send(RawMsg::Response(RawResponse {
-            id: Some(self.id),
-            result: serde_json::to_value(result)?,
-            error: serde_json::Value::Null,
-        }));
-        Ok(())
-    }
-
-    pub fn error(mut self, io: &mut Io) -> Result<()> {
-        self.bomb.defuse();
-        error(io, self.id, ErrorCode::InternalError, "internal error")
+        let res = match result {
+            Ok(result) => {
+                RawResponse {
+                    id: Some(self.id),
+                    result: serde_json::to_value(result)?,
+                    error: serde_json::Value::Null,
+                }
+            }
+            Err(_) => {
+                error_response(self.id, ErrorCode::InternalError, "internal error")?
+            }
+        };
+        Ok(res)
     }
 }
 
-
 fn parse_request_as<R: ClientRequest>(raw: RawRequest)
-    -> Result<::std::result::Result<(R::Params, Responder<R>), RawRequest>>
+                                      -> Result<::std::result::Result<(R::Params, Responder<R>), RawRequest>>
 {
     if raw.method != R::METHOD {
         return Ok(Err(raw));
@@ -77,13 +66,13 @@ pub fn handle_request<R, F>(req: &mut Option<RawRequest>, f: F) -> Result<()>
             Err(r) => {
                 *req = Some(r);
                 Ok(())
-            },
+            }
         }
     }
 }
 
 pub fn expect_request<R: ClientRequest>(io: &mut Io, raw: RawRequest)
-    -> Result<Option<(R::Params, Responder<R>)>>
+                                        -> Result<Option<(R::Params, Responder<R>)>>
 {
     let ret = match parse_request_as::<R>(raw)? {
         Ok(x) => Some(x),
@@ -120,21 +109,21 @@ pub fn handle_notification<N, F>(not: &mut Option<RawNotification>, f: F) -> Res
             Err(n) => {
                 *not = Some(n);
                 Ok(())
-            },
+            }
         }
     }
 }
 
-pub fn send_notification<N>(io: &mut Io, params: N::Params) -> Result<()>
+pub fn send_notification<N>(params: N::Params) -> RawNotification
     where
         N: Notification,
         N::Params: Serialize
 {
-    io.send(RawMsg::Notification(RawNotification {
+    RawNotification {
         method: N::METHOD.to_string(),
-        params: serde_json::to_value(params)?,
-    }));
-    Ok(())
+        params: serde_json::to_value(params)
+            .unwrap(),
+    }
 }
 
 
@@ -142,20 +131,26 @@ pub fn unknown_method(io: &mut Io, raw: RawRequest) -> Result<()> {
     error(io, raw.id, ErrorCode::MethodNotFound, "unknown method")
 }
 
-fn error(io: &mut Io, id: u64, code: ErrorCode, message: &'static str) -> Result<()> {
+fn error_response(id: u64, code: ErrorCode, message: &'static str) -> Result<RawResponse> {
     #[derive(Serialize)]
     struct Error {
         code: i32,
         message: &'static str,
     }
-    io.send(RawMsg::Response(RawResponse {
+    let resp = RawResponse {
         id: Some(id),
         result: serde_json::Value::Null,
         error: serde_json::to_value(Error {
             code: code as i32,
             message,
         })?,
-    }));
+    };
+    Ok(resp)
+}
+
+fn error(io: &mut Io, id: u64, code: ErrorCode, message: &'static str) -> Result<()> {
+    let resp = error_response(id, code, message)?;
+    io.send(RawMsg::Response(resp));
     Ok(())
 }
 
diff --git a/crates/server/src/main.rs b/crates/server/src/main.rs
index 3ff300e3d..be63fea93 100644
--- a/crates/server/src/main.rs
+++ b/crates/server/src/main.rs
@@ -32,10 +32,10 @@ use languageserver_types::Url;
 use libanalysis::{WorldState, World};
 
 use ::{
-    io::{Io, RawMsg, RawRequest},
+    io::{Io, RawMsg, RawRequest, RawResponse, RawNotification},
     handlers::{handle_syntax_tree, handle_extend_selection, publish_diagnostics, publish_decorations,
                handle_document_symbol, handle_code_action},
-    util::{FilePath, FnBox}
+    util::FilePath,
 };
 
 pub type Result<T> = ::std::result::Result<T, ::failure::Error>;
@@ -80,9 +80,9 @@ fn initialize(io: &mut Io) -> Result<()> {
         match io.recv()? {
             RawMsg::Request(req) => {
                 if let Some((_params, resp)) = dispatch::expect_request::<req::Initialize>(io, req)? {
-                    resp.result(io, req::InitializeResult {
-                        capabilities: caps::SERVER_CAPABILITIES
-                    })?;
+                    let res = req::InitializeResult { capabilities: caps::SERVER_CAPABILITIES };
+                    let resp = resp.into_response(Ok(res))?;
+                    io.send(RawMsg::Response(resp));
                     match io.recv()? {
                         RawMsg::Notification(n) => {
                             if n.method != "initialized" {
@@ -106,13 +106,18 @@ fn initialize(io: &mut Io) -> Result<()> {
     }
 }
 
-type Thunk = Box<for<'a> FnBox<&'a mut Io, Result<()>>>;
+
+enum Task {
+    Respond(RawResponse),
+    Notify(RawNotification),
+    Die(::failure::Error),
+}
 
 fn initialized(io: &mut Io) -> Result<()> {
     {
         let mut world = WorldState::new();
         let mut pool = ThreadPool::new(4);
-        let (sender, receiver) = bounded::<Thunk>(16);
+        let (sender, receiver) = bounded::<Task>(16);
         info!("lifecycle: handshake finished, server ready to serve requests");
         let res = main_loop(io, &mut world, &mut pool, sender, receiver.clone());
         info!("waiting for background jobs to finish...");
@@ -140,14 +145,14 @@ fn main_loop(
     io: &mut Io,
     world: &mut WorldState,
     pool: &mut ThreadPool,
-    sender: Sender<Thunk>,
-    receiver: Receiver<Thunk>,
+    sender: Sender<Task>,
+    receiver: Receiver<Task>,
 ) -> Result<()> {
     info!("server initialized, serving requests");
     loop {
         enum Event {
             Msg(RawMsg),
-            Thunk(Thunk),
+            Task(Task),
             ReceiverDead,
         }
 
@@ -156,7 +161,7 @@ fn main_loop(
                 Some(msg) => Event::Msg(msg),
                 None => Event::ReceiverDead,
             },
-            recv(receiver, thunk) => Event::Thunk(thunk.unwrap()),
+            recv(receiver, task) => Event::Task(task.unwrap()),
         };
 
         let msg = match event {
@@ -164,8 +169,15 @@ fn main_loop(
                 io.cleanup_receiver()?;
                 unreachable!();
             }
-            Event::Thunk(thunk) => {
-                thunk.call_box(io)?;
+            Event::Task(task) => {
+                match task {
+                    Task::Respond(response) =>
+                        io.send(RawMsg::Response(response)),
+                    Task::Notify(n) =>
+                        io.send(RawMsg::Notification(n)),
+                    Task::Die(error) =>
+                        return Err(error),
+                }
                 continue;
             }
             Event::Msg(msg) => msg,
@@ -175,21 +187,22 @@ fn main_loop(
             RawMsg::Request(req) => {
                 let mut req = Some(req);
                 handle_request_on_threadpool::<req::SyntaxTree>(
-                    &mut req, pool, world, &sender, handle_syntax_tree
+                    &mut req, pool, world, &sender, handle_syntax_tree,
                 )?;
                 handle_request_on_threadpool::<req::ExtendSelection>(
-                    &mut req, pool, world, &sender, handle_extend_selection
+                    &mut req, pool, world, &sender, handle_extend_selection,
                 )?;
                 handle_request_on_threadpool::<req::DocumentSymbolRequest>(
-                    &mut req, pool, world, &sender, handle_document_symbol
+                    &mut req, pool, world, &sender, handle_document_symbol,
                 )?;
                 handle_request_on_threadpool::<req::CodeActionRequest>(
-                    &mut req, pool, world, &sender, handle_code_action
+                    &mut req, pool, world, &sender, handle_code_action,
                 )?;
 
                 let mut shutdown = false;
                 dispatch::handle_request::<req::Shutdown, _>(&mut req, |(), resp| {
-                    resp.result(io, ())?;
+                    let resp = resp.into_response(Ok(()))?;
+                    io.send(RawMsg::Response(resp));
                     shutdown = true;
                     Ok(())
                 })?;
@@ -227,10 +240,12 @@ fn main_loop(
                 dispatch::handle_notification::<req::DidCloseTextDocument, _>(&mut not, |params| {
                     let path = params.text_document.file_path()?;
                     world.change_overlay(path, None);
-                    dispatch::send_notification::<req::PublishDiagnostics>(io, req::PublishDiagnosticsParams {
+                    let not = req::PublishDiagnosticsParams {
                         uri: params.text_document.uri,
                         diagnostics: Vec::new(),
-                    })?;
+                    };
+                    let not = dispatch::send_notification::<req::PublishDiagnostics>(not);
+                    io.send(RawMsg::Notification(not));
                     Ok(())
                 })?;
 
@@ -249,7 +264,7 @@ fn handle_request_on_threadpool<R: req::ClientRequest>(
     req: &mut Option<RawRequest>,
     pool: &ThreadPool,
     world: &WorldState,
-    sender: &Sender<Thunk>,
+    sender: &Sender<Task>,
     f: fn(World, R::Params) -> Result<R::Result>,
 ) -> Result<()>
 {
@@ -258,7 +273,11 @@ fn handle_request_on_threadpool<R: req::ClientRequest>(
         let sender = sender.clone();
         pool.execute(move || {
             let res = f(world, params);
-            sender.send(Box::new(|io: &mut Io| resp.response(io, res)))
+            let task = match resp.into_response(res) {
+                Ok(resp) => Task::Respond(resp),
+                Err(e) => Task::Die(e),
+            };
+            sender.send(task);
         });
         Ok(())
     })
@@ -267,7 +286,7 @@ fn handle_request_on_threadpool<R: req::ClientRequest>(
 fn update_file_notifications_on_threadpool(
     pool: &ThreadPool,
     world: World,
-    sender: Sender<Thunk>,
+    sender: Sender<Task>,
     uri: Url,
 ) {
     pool.execute(move || {
@@ -276,9 +295,8 @@ fn update_file_notifications_on_threadpool(
                 error!("failed to compute diagnostics: {:?}", e)
             }
             Ok(params) => {
-                sender.send(Box::new(|io: &mut Io| {
-                    dispatch::send_notification::<req::PublishDiagnostics>(io, params)
-                }))
+                let not = dispatch::send_notification::<req::PublishDiagnostics>(params);
+                sender.send(Task::Notify(not));
             }
         }
         match publish_decorations(world, uri) {
@@ -286,9 +304,8 @@ fn update_file_notifications_on_threadpool(
                 error!("failed to compute decortions: {:?}", e)
             }
             Ok(params) => {
-                sender.send(Box::new(|io: &mut Io| {
-                    dispatch::send_notification::<req::PublishDecorations>(io, params)
-                }))
+                let not = dispatch::send_notification::<req::PublishDecorations>(params);
+                sender.send(Task::Notify(not))
             }
         }
     });
diff --git a/crates/server/src/util.rs b/crates/server/src/util.rs
index e4c226f93..6747c20a8 100644
--- a/crates/server/src/util.rs
+++ b/crates/server/src/util.rs
@@ -3,16 +3,6 @@ use languageserver_types::{TextDocumentItem, VersionedTextDocumentIdentifier,
                            TextDocumentIdentifier, Url};
 use ::{Result};
 
-pub trait FnBox<A, R>: Send {
-    fn call_box(self: Box<Self>, a: A) -> R;
-}
-
-impl<A, R, F: FnOnce(A) -> R + Send> FnBox<A, R> for F {
-    fn call_box(self: Box<F>, a: A) -> R {
-        (*self)(a)
-    }
-}
-
 pub trait FilePath {
     fn file_path(&self) -> Result<PathBuf>;
 }