Package: emacs;
Reported by: Augusto Stoffel <arstoffel <at> gmail.com>
Date: Sun, 28 Jul 2024 18:09:01 UTC
Severity: normal
Tags: patch
Message #47 received at 72343 <at> debbugs.gnu.org (full text, mbox):
From: João Távora <joaotavora <at> gmail.com> To: Augusto Stoffel <arstoffel <at> gmail.com> Cc: Eli Zaretskii <eliz <at> gnu.org>, 72343 <at> debbugs.gnu.org Subject: Re: bug#72343: [PATCH] Fix eglot-server-programs for TeX modes Date: Tue, 6 Aug 2024 19:08:45 +0100
On Tue, Aug 6, 2024 at 5:38 PM Augusto Stoffel <arstoffel <at> gmail.com> wrote: > > So there's no "single pick" in general. > You don't need to explain that to me ;-). It is you who alluded to a single pick, so I thought I had to. Also earlier you proposed multiple entries in eglot-server-programs, which would impede this multi-language-per-session feature. So I figured you wouldn't be familiar with it. > What I want to achieve (or, if I may, what Eglot should do) in case it > wasn't clear yet, is: file x.tex is sent language id "latex" and file > y.tex is sent language id "plain-tex". Indeed it wasn't clear, so I'm very glad I asked. I don't see "plain-tex" in the list over at https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/ I just see "tex" and "latex" and "bibtex". Now, if you want "latex" to be sent for x.tex (in latex-mode) and "tex" to be sent for x.tex (in plain-tex-mode), there is this possibility. diff --git a/lisp/progmodes/eglot.el b/lisp/progmodes/eglot.el index 5845aff39b7..2695aa93ffe 100644 --- a/lisp/progmodes/eglot.el +++ b/lisp/progmodes/eglot.el @@ -292,7 +292,7 @@ eglot-server-programs (scala-mode . ,(eglot-alternatives '("metals" "metals-emacs"))) (racket-mode . ("racket" "-l" "racket-langserver")) - ((tex-mode context-mode texinfo-mode bibtex-mode) + ((latex-mode tex-mode context-mode texinfo-mode bibtex-mode) . ,(eglot-alternatives '("digestif" "texlab"))) (erlang-mode . ("erlang_ls" "--transport" "stdio")) ((yaml-ts-mode yaml-mode) . ("yaml-language-server" "--stdio")) No need to mention plain-tex-mode at all. The "guess" logic will work (though I still recommend :language-id cookie). You might notice this will only work for a particular sequence of invocations (specifically starting the server with the latex-mode file open, then opening other files in plain-tex-mode). But it won't for many other cases. The fact that Emacs models latex-mode as a descendent of tex-mode is something Eglot can't do anything about. It means that Emacs thinks that that every LaTex program is a TeX program at least at some syntactic level (is this true? no idea). So as soon as you have the two files open, M-x eglot-reconnect will send "tex" for _both_. Which, according to Emacs's view of the world, isn't wrong. This has happened before with the js/json mode and has been fixed in the mode relations. I think bug#67463. The same idea thatfixed it there could be applied here. Anyway, if plain-tex-mode is an attempt to fix this, by making a core mode that is not directly related to latex-mode, then I think it should appear in the list, but then :language-id set to to "tex". But I see plain-tex-mode also inherits from tex-mode, so the fundamental problem remains. Unless you remove tex-mode from the list (which is what you did). But then outside descendents of tex-mode would be cut off, which is what I warned about. I do think that's the lesser of two evils though. So anyway this is my suggestion: @@ -292,7 +292,7 @@ eglot-server-programs (scala-mode . ,(eglot-alternatives '("metals" "metals-emacs"))) (racket-mode . ("racket" "-l" "racket-langserver")) - ((tex-mode context-mode texinfo-mode bibtex-mode) + ((latex-mode (plain-tex-mode :language-id "tex") context-mode texinfo-mode bibtex-mode) . ,(eglot-alternatives '("digestif" "texlab"))) (erlang-mode . ("erlang_ls" "--transport" "stdio")) ((yaml-ts-mode yaml-mode) . ("yaml-language-server" "--stdio")) In theory, this could also be fixed by keeping tex-mode in there, and then adjusting Eglot's heuristic, by ranking the potential ancestors and selecting the closest one, in 'eglot--languageId'. Could be tricky or could be easy, feel free to give it a shot. Yet another idea is to not reorder modes at all in 'eglot--lookup-mode' and use an explicit order to express this ranking. I admit I don't remember what the reordering idea (main-mode-sym is the local var name) is for. it couldprecede the multiple-language-ids feature. Or it could be essential for some other thing: testing would be needed. > This doesn't matter, as it's an Eglot issue. Any TeX server will do. This is not established, at least not yet. You are requesting for a "plain-tex" LSP languageId property to be sent and that is outside the spec as far as I can tell from reading the spec. Maybe your digestif server supports and likes it, though. But it might break "texlab" for all I know. Even the fact that "tex" is all that's being sent at the moment may or may not be a bug -- only LaTex/Tex specialists can say that. And certainly a capable enough language server, which is tasked with analysing a file syntactically, can do much the same as our own tex-mode.el and figure out the correct language from the contents. Might do it better than Emacs. That said, if you really want to send "plain-tex", then there are two options. You can change your user value of eglot-server-programs, obviously. Or you can confirm with "texlab" that they don't mind, in which case -- but only in that case -- your latest patch is acceptable.
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.