Language service features could provide streaming/progressive results

[Colengms]

Feature Request

Recent LSP versions have added support for partial/progressive results. https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#progress

The base protocol offers also support to report progress in a generic fashion. This mechanism can be used to report any kind of progress including work done progress (usually used to report progress in the user interface using a progress bar) and partial result progress to support streaming of results.

Cpptools features like FAR (Rename, call hierarchy) currently provide a way to get partial requests, by clicking on a magnifying glass icon at the bottom of the screen. That is cpptools-specific behavior. That support could potentially be removed if streaming results instead.

While it doesn't look like VS Code supports progressive results via their provider classes (as far as I can tell, from the ones I looked at), their LSP implementation appears to support it.

There are also now 'semantic tokens' and 'diagnostics' LSP requests. We have some known issues with diagnostics merging ( microsoft/vscode#199724 ) that could possibly be addressed by using the diagnostics LSP request with streamed results.