1 files changed, 44 insertions, 0 deletions

diff --git a/crates/rust-analyzer/src/lsp_utils.rs b/crates/rust-analyzer/src/lsp_utils.rs
new file mode 100644
index 000000000..078f8778e
--- /dev/null
+++ b/crates/rust-analyzer/src/lsp_utils.rs
@@ -0,0 +1,44 @@
+//! Utilities for LSP-related boilerplate code.
+use std::error::Error;
+
+use crossbeam_channel::Sender;
+use lsp_server::{Message, Notification};
+use ra_db::Canceled;
+use serde::{de::DeserializeOwned, Serialize};
+
+pub fn show_message(
+    typ: lsp_types::MessageType,
+    message: impl Into<String>,
+    sender: &Sender<Message>,
+) {
+    let message = message.into();
+    let params = lsp_types::ShowMessageParams { typ, message };
+    let not = notification_new::<lsp_types::notification::ShowMessage>(params);
+    sender.send(not.into()).unwrap();
+}
+
+pub(crate) fn is_canceled(e: &(dyn Error + 'static)) -> bool {
+    e.downcast_ref::<Canceled>().is_some()
+}
+
+pub(crate) fn notification_is<N: lsp_types::notification::Notification>(
+    notification: &Notification,
+) -> bool {
+    notification.method == N::METHOD
+}
+
+pub(crate) fn notification_cast<N>(notification: Notification) -> Result<N::Params, Notification>
+where
+    N: lsp_types::notification::Notification,
+    N::Params: DeserializeOwned,
+{
+    notification.extract(N::METHOD)
+}
+
+pub(crate) fn notification_new<N>(params: N::Params) -> Notification
+where
+    N: lsp_types::notification::Notification,
+    N::Params: Serialize,
+{
+    Notification::new(N::METHOD.to_string(), params)
+}