pref: reduce the number of LSP RPC calls

lang/lsp/client.go

@@ -36,7 +36,6 @@ type LSPClient struct {
 	*lspHandler
 	tokenTypes             []string
 	tokenModifiers         []string
-	hasSemanticTokensRange bool
 	files                  map[DocumentURI]*TextDocumentItem
 	provider               LanguageServiceProvider
 	ClientOptions
@@ -193,8 +192,6 @@ func initLSPClient(ctx context.Context, svr io.ReadWriteCloser, dir DocumentURI,
 	if !ok || semanticTokensProvider == nil {
 		return nil, fmt.Errorf("server did not provide SemanticTokensProvider")
 	}
-	semanticTokensRange, ok := semanticTokensProvider["range"].(bool)
-	cli.hasSemanticTokensRange = ok && semanticTokensRange
 	legend, ok := semanticTokensProvider["legend"].(map[string]interface{})
 	if !ok || legend == nil {
 		return nil, fmt.Errorf("server did not provide SemanticTokensProvider.legend")

lang/lsp/lsp.go

@@ -171,13 +171,14 @@ func NewURI(file string) DocumentURI {
 }
 
 type TextDocumentItem struct {
-	URI         DocumentURI               `json:"uri"`
-	LanguageID  string                    `json:"languageId"`
-	Version     int                       `json:"version"`
-	Text        string                    `json:"text"`
-	LineCounts  []int                     `json:"-"`
-	Symbols     map[Range]*DocumentSymbol `json:"-"`
-	Definitions map[Position][]Location   `json:"-"`
+	URI            DocumentURI               `json:"uri"`
+	LanguageID     string                    `json:"languageId"`
+	Version        int                       `json:"version"`
+	Text           string                    `json:"text"`
+	LineCounts     []int                     `json:"-"`
+	Symbols        map[Range]*DocumentSymbol `json:"-"`
+	Definitions    map[Position][]Location   `json:"-"`
+	SemanticTokens *SemanticTokens           `json:"-"`
 }
 
 type DocumentSymbol struct {

lang/lsp/lsp_methods.go

@@ -156,22 +156,27 @@ func (cli *LSPClient) References(ctx context.Context, id Location) ([]Location,
 	return resp, nil
 }
 
-// Some language servers do not provide semanticTokens/range.
-// In that case, we fall back to semanticTokens/full and then filter the tokens manually.
 func (cli *LSPClient) getSemanticTokensRange(ctx context.Context, req DocumentRange, resp *SemanticTokens) error {
-	if cli.hasSemanticTokensRange {
-		if err := cli.Call(ctx, "textDocument/semanticTokens/range", req, resp); err != nil {
+	f, err := cli.DidOpen(ctx, DocumentURI(req.TextDocument.URI))
+	if err != nil {
+		return err
+	}
+
+	if f.SemanticTokens == nil {
+		req1 := SemanticTokensFullParams{
+			TextDocument: req.TextDocument,
+		}
+		var fullResp SemanticTokens
+		if err := cli.Call(ctx, "textDocument/semanticTokens/full", req1, &fullResp); err != nil {
 			return err
 		}
-		return nil
-	}
-	// fall back to semanticTokens/full
-	req1 := SemanticTokensFullParams{
-		TextDocument: req.TextDocument,
-	}
-	if err := cli.Call(ctx, "textDocument/semanticTokens/full", req1, resp); err != nil {
-		return err
+		f.SemanticTokens = &fullResp
 	}
+
+	resp.ResultID = f.SemanticTokens.ResultID
+	resp.Data = make([]uint32, len(f.SemanticTokens.Data))
+	copy(resp.Data, f.SemanticTokens.Data)
+
 	filterSemanticTokensInRange(resp, req.Range)
 	return nil
 }

lang/utils/files.go

@@ -28,7 +28,7 @@ func CountFiles(dir string, subfix string, skipdir string) (int, int) {
 	skipdir, _ = filepath.Abs(filepath.Join(dir, skipdir))
 	filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
 		if strings.HasPrefix(path, skipdir) {
-			return nil
+			return filepath.SkipDir
 		}
 		if !info.IsDir() && filepath.Ext(path) == subfix {
 			count++