Re: Eglot "inlay hints" landed

[Chinmay Dalal]

Chinmay Dalal <dalal.chinmay.0101@gmail.com> writes:

> 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)
>
>
> [2. empty overlay --- image/png; swappy-20230224-100015.png]...


Of course, this is not ideal when there are multiple elements in the
label list (but not strictly wrong either). I raised this point when I
opened bug#61412:
https://mail.gnu.org/archive/html/bug-gnu-emacs/2023-02/msg00760.html

Also, can the clickable link be actually implemented using the `keymap`
property of overlays:
https://www.gnu.org/software/emacs/manual/html_node/elisp/Special-Properties.html#index-keymap-of-character
instead of just displaying the text?

Chinmay