Re: Elisp LSP Server

[Dmitry Gutov]

On 10.10.2021 15:48, Ag Ibragimov wrote:
> LSP, for many Emacsen has become a true game-changer. You don't have to 
> re-invent the wheel for every single different language, no need to map and 
> re-map the keys (separately for every language) or struggle when a language 
> mode package authors fail to include some features.
> Wouldn't it be ironic if soon, Emacs gets truly fantastic support for dozens of 
> languages (btw, that list is still growing), yet Elisp would have to ride like 
> a second-class passenger?

I see where you going with this: if we just consolidated our languages 
support code as an LSP client and moved Elisp implementation to an LSP 
server, we might be better able to focus on a language support UI which 
is the same across languages.

Unfortunately, it's not so simple: even aside from the JSON transport 
(which we could get around by offering different transport options), the 
LSP protocol has limitations which would limit us on certain features.

For example, you can 'C-u M-.' in an Emacs Lisp buffer, then press TAB 
and see all the available symbols you can navigate to; I'm told this is 
either impossible to support with the current LSP protocol, or pretty 
hard to do.

Other examples are in how completions information is presented; it's 
basically tailored to VS Code's completion popup. LSP clients are 
saddled with certain drawbacks when you use company-mode.

Maybe someday.

Instead, we're currently focusing on reusable UI workflows.