Re: Eglot "inlay hints" landed

[Chinmay Dalal]

João Távora <joaotavora@gmail.com> writes:

> On Thu, Feb 23, 2023 at 7:50 PM Nikola Pajkovsky <n.pajkovsky@gmail.com> 
> wrote:
>>
>> João Távora <joaotavora@gmail.com> writes:
>>
>> > I've just landed Eglot "inlay hints" on lisp/progmodes/eglot.el in the
>> > emacs-29 branch.  It's a feature that some users (including me) were
>> > looking for for some time.
>>
>> Nice work João!
>>
>> I tried rust inlay hints, and it does not work for me. I bet it's because
>> eglot uses label only if it's string. The same problem was in lsp-mode.
>
> Actually, I think I have code for that.  So please show a reproduction
> recipe.  I think someone reported here that hints are working
> correctly with rust-analyzer, and I've tried it briefly myself with good
> results. So it must be something else.
>
> João


You can look at the end of any long rust function with hl-line-mode on:
there's an empty overlay but it's supposed to have a link to the
beginning of the function. Screenshot attached.

I think the bug is in eglot--update-hints-1:

(if (stringp label) label (plist-get label :value))

It should instead be the value of :value from the _first element_ of
label, as the spec says a label is a string or a _list of_ 
`InlayHintLabelPart`s:

https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#inlayHint

The response from the server is of this form:

(:position (:line 95 :character 1)
 :label [(:value "fn keyboard_interrupt_handler"
          :location (:uri 
"file:///home/chinmay/stuff/rust/blog_os/src/interrupts.rs"
                     :range (:start (:line 67 :character 26)
                             :end (:line 67 :character 52))))]
 :tooltip "fn keyboard_interrupt_handler"
 :paddingLeft t
 :paddingRight
 :json-false)

swappy-20230224-100015.png
Description: empty overlay