Refactor DiagnosticProvider as an enum

This resolves a TODO in the core diagnostic module to refactor this
type. It was originally an alias of `LanguageServerId` for simplicity.
Refactoring as an enum is a necessary step towards introducing
"internal" diagnostics - diagnostics emitted by core features such as
a spell checker. Fully supporting this use-case will require further
larger changes to the diagnostic type, but the change to the provider
can be made first.

Note that `Copy` is not derived for `DiagnosticProvider` (as it was
previously because `LanguageServerId` is `Copy`). In the child commits
we will add the `identifier` used in LSP pull diagnostics which is a
string - not `Copy`.

helix-term/src/application.rs

@@ -740,8 +740,10 @@ impl Application {
                             log::error!("Discarding publishDiagnostic notification sent by an uninitialized server: {}", language_server.name());
                             return;
                         }
+                        let provider =
+                            helix_core::diagnostic::DiagnosticProvider::Lsp { server_id };
                         self.editor.handle_lsp_diagnostics(
-                            language_server.id(),
+                            &provider,
                             uri,
                             params.version,
                             params.diagnostics,
@@ -854,14 +856,16 @@ impl Application {
                         // we need to clear those and remove the entries from the list if this leads to
                         // an empty diagnostic list for said files
                         for diags in self.editor.diagnostics.values_mut() {
-                            diags.retain(|(_, lsp_id)| *lsp_id != server_id);
+                            diags.retain(|(_, provider)| {
+                                provider.language_server_id() != Some(server_id)
+                            });
                         }
 
                         self.editor.diagnostics.retain(|_, diags| !diags.is_empty());
 
                         // Clear any diagnostics for documents with this server open.
                         for doc in self.editor.documents_mut() {
-                            doc.clear_diagnostics(Some(server_id));
+                            doc.clear_diagnostics_for_language_server(server_id);
                         }
 
                         // Remove the language server from the registry.

helix-term/src/commands/lsp.rs

@@ -14,7 +14,8 @@ use tui::{text::Span, widgets::Row};
 use super::{align_view, push_jump, Align, Context, Editor};
 
 use helix_core::{
-    syntax::LanguageServerFeature, text_annotations::InlineAnnotation, Selection, Uri,
+    diagnostic::DiagnosticProvider, syntax::LanguageServerFeature,
+    text_annotations::InlineAnnotation, Selection, Uri,
 };
 use helix_stdx::path;
 use helix_view::{
@@ -31,13 +32,7 @@ use crate::{
     ui::{self, overlay::overlaid, FileLocation, Picker, Popup, PromptEvent},
 };
 
-use std::{
-    cmp::Ordering,
-    collections::{BTreeMap, HashSet},
-    fmt::Display,
-    future::Future,
-    path::Path,
-};
+use std::{cmp::Ordering, collections::HashSet, fmt::Display, future::Future, path::Path};
 
 /// Gets the first language server that is attached to a document which supports a specific feature.
 /// If there is no configured language server that supports the feature, this displays a status message.
@@ -209,7 +204,7 @@ type DiagnosticsPicker = Picker<PickerDiagnostic, DiagnosticStyles>;
 
 fn diag_picker(
     cx: &Context,
-    diagnostics: BTreeMap<Uri, Vec<(lsp::Diagnostic, LanguageServerId)>>,
+    diagnostics: impl IntoIterator<Item = (Uri, Vec<(lsp::Diagnostic, DiagnosticProvider)>)>,
     format: DiagnosticsFormat,
 ) -> DiagnosticsPicker {
     // TODO: drop current_path comparison and instead use workspace: bool flag?
@@ -219,8 +214,11 @@ fn diag_picker(
     for (uri, diags) in diagnostics {
         flat_diag.reserve(diags.len());
 
-        for (diag, ls) in diags {
-            if let Some(ls) = cx.editor.language_server_by_id(ls) {
+        for (diag, provider) in diags {
+            if let Some(ls) = provider
+                .language_server_id()
+                .and_then(|id| cx.editor.language_server_by_id(id))
+            {
                 flat_diag.push(PickerDiagnostic {
                     location: Location {
                         uri: uri.clone(),
@@ -560,11 +558,7 @@ pub fn diagnostics_picker(cx: &mut Context) {
     let doc = doc!(cx.editor);
     if let Some(uri) = doc.uri() {
         let diagnostics = cx.editor.diagnostics.get(&uri).cloned().unwrap_or_default();
-        let picker = diag_picker(
-            cx,
-            [(uri, diagnostics)].into(),
-            DiagnosticsFormat::HideSourcePath,
-        );
+        let picker = diag_picker(cx, [(uri, diagnostics)], DiagnosticsFormat::HideSourcePath);
         cx.push_layer(Box::new(overlaid(picker)));
     }
 }

helix-term/src/commands/typed.rs

@@ -1622,7 +1622,7 @@ fn lsp_stop(cx: &mut compositor::Context, args: Args, event: PromptEvent) -> any
 
         for doc in cx.editor.documents_mut() {
             if let Some(client) = doc.remove_language_server_by_name(ls_name) {
-                doc.clear_diagnostics(Some(client.id()));
+                doc.clear_diagnostics_for_language_server(client.id());
                 doc.reset_all_inlay_hints();
                 doc.inlay_hints_oudated = true;
             }