language server protocol for Kawa

[Per Bothner]

Has anyone done any work for a Language Server Protocol
(https://langserver.org/) for Kawa? Any insights or partial code?

I ask because I'm getting ready to jump into this as the next major
project for Kawa.

(I do have one non-trivial bug It want to resolve first:
GitLab issue #33 and Savannah bug #52390, which are probably both related to
the fix for issue #11).

[Duncan Mak]

Hello Per,

i started doing this a few months ago, but I didn't get very far at all.

Perhaps it's because of how I tried to do it - I looked at
https://github.com/palantir/language-servers and
https://github.com/eclipse/lsp4j and tried to implement the
LanguageClientAware and LanguageServer interfaces.

The Groovy implementation is here -
https://github.com/palantir/language-servers/blob/develop/groovy-language-server/src/main/java/com/palantir/ls/groovy/GroovyLanguageServer.java

It was difficult to know if I'm making progress, because it seemed
like all the things needed to come together all at the same time.

If you're jumping into working on an LSP implementation, I'd love to
contribute on GitLab if you can post issues with tasks for others to
complete.



Duncan.

Post by Per Bothner
Has anyone done any work for a Language Server Protocol
(https://langserver.org/) for Kawa? Any insights or partial code?
I ask because I'm getting ready to jump into this as the next major
project for Kawa.
GitLab issue #33 and Savannah bug #52390, which are probably both related to
the fix for issue #11).
--
--Per Bothner

[Per Bothner]

Post by Duncan Mak
It was difficult to know if I'm making progress, because it seemed
like all the things needed to come together all at the same time.
If you're jumping into working on an LSP implementation, I'd love to
contribute on GitLab if you can post issues with tasks for others to
complete.

That's why I think I need to do at least a bare-bones implementation,
since I have the Kawa big-picture. Once I have *something* working,
then asking for help makes sense.

[Helmut Eller]

Post by Per Bothner
Has anyone done any work for a Language Server Protocol
(https://langserver.org/) for Kawa? Any insights or partial code?

Just some thoughts:

- For Kawa's Java code I'm using the Emacs lsp-mode as client and
Eclipse's jdt-server. While I wouldn't call that combo great, it
certainly helps navigating the code. (I'm still using make directly to
compile things.)

- It seems to me that an LSP server would like to have something like a
"project" file that lists the interesting source files, libraries etc.
I suppose plain Makefiles will not work so well for that; maybe Ant
files would work better. Or maybe Kawa should have something like
Rust's Cargo. My guess is that this will be an important design
decision.

Helmut

[Per Bothner]

Post by Helmut Eller
- It seems to me that an LSP server would like to have something like a
"project" file that lists the interesting source files, libraries etc.
I suppose plain Makefiles will not work so well for that; maybe Ant
files would work better. Or maybe Kawa should have something like
Rust's Cargo. My guess is that this will be an important design
decision.

Definitely things to ponder and research, which I have barely started on.

I would like to have good defaults, so at least basic syntax checking
(and syntax coloring) works even without a project file. That is one
of the things I like about Emacs - you can edit a file without having
create a project containing the file.

I'd also like the server to be able to use import, module-name,
require, and define-library forms to find definitions.

However, in general one will want some kind of project file - for
example for compiler options or adding jar files to a classpath.
This is something I will need to study other servers for.

Scanning a Makefile for project properties doesn't seem like
it would be difficult - at least string-valued properties.
The Makefiles would have to follow certain conventions, just
like automake source files already do.