Can VS Code support CLion-like type-hint?

[crlf0710]

CLion can display a "span" prompting the auto deduced type/argument name/etc. I wonder if this is possible in VS Code too? (Doesn't have to be exactly the same.)

[phiresky]

Do you mean like this?

[nrc]

Woah, how did you do that?

[phiresky]

My actual goal was to do parameter hints like IntelliJ (which can be done heuristically e.g. only when there are >3 params or when multiple parameters have the same type). I could not find a way to get that information out of the compiler / from rls-analysis (would maybe need to walk the AST to find all function call tokens?).

The protocol does not support this by default, there is an open issue for VScode here: microsoft/vscode#16221, so I used a custom notification sent from DocumentSymbols which has the most relevant information and is called on every document change for me.

See these two patches: rls-vscode, rls.

[nrc]

@phiresky Nice!

TODO: how would you send a notification from a RequestAction asynchronously (without blocking?)

Why does it need to be a blocking request? We usually only use these for lifecycle requests.

I don't think the notifcation needs to be sent async - we're not waiting for a reply or anything, so sending a reply is fast.

[phiresky]

Why does it need to be a blocking request?

The only reason I changed it to a BlockingRequestAction is because I couldn't find a way to get a reference to the Output instance (to call output.notify) from the ActionContext given to the RequestAction.

I didn't really mean async.. just meant without making the Symbols RequestAction a BlockingRequestAction. I'm not a Rust expert as you might have noticed :)

I'm also not sure if this is even the right place to put that (and who actually calls DocumentSymbols and why)

[nrc]

I think the right approach is to include that data in the response rather than sending a separate notification. Not sure if there are fields you can use already to do that, but if not, you can always add custom fields to the protocol messages.

[Kreyren]

What is the status on this?

[DCjanus]

@Kreyren It seems done.

[Kreyren]

@DCjanus can't confirm on my end, is there any specific configuration for this?

[DCjanus]

oh, I just made a silly mistake, I'm using rust-analyzer and I thout we are talking about it.

(I subscribed this issue long time ago, when notification came, I thout it's from rust-analyzer)