ack_responses

[philip-alldredge]

This pull request fixes the RLS not sending response when result is empty such as when the result of type Ack. I came across this when experimenting with using the RLS in Eclipse via LSP4E/LSP4J. Those libraries wait for a response even if the result is expected to be empty or null. I'm an new at rust so this may be an inappropriate way to solve the problem.

[nrc]

Hi, thanks for the PR! I think there might be a better way to fix this problem - I think that whether a response should be sent or not should be a property of the response type rather than property of the action. So, if we want to not send a response then the response type should be NoResponse (a new zero-sized type), rather than ().

I'm not sure exactly the best way to then send or not send a response, but probably the best way is to add a Response trait with a send method where there is a default implementation that calls out.success and NoResponse does nothing.

[nrc]

And a very minor point, could you take a look at your editor tab settings - there is a mix of tabs and spaces in the PR. The RLS uses four spaces for tabs.

[philip-alldredge]

I have pushed the requested changes. However, the Response trait doesn't have a default implementation because it requires the type for which the train is implemented to be serializable so that out.success may be called.

[nrc]

This looks great, thanks for the changes!