Project status?

[wilhelmy]

Hi, not an actual issue but I have no idea where else to ask questions about this project.

Just wondering, is this still alive? The organization overview says it was modified 27 days ago but I didn't see any recent commits...

[Armael]

Hi! Thanks for your interest.

I believe the "27 days ago" refers to the currently opened pull request.
As for the current status of the project: this is an experiment that I started some time ago, and that I'd still like to pursue someday; however, I haven't had time to work on it for a while, and don't currently have that much time either.

That being said, I'd still think this is an interesting endeavor, that I hope I'll be able to pick up again at some point. There are several interesting problems to be solved here: for instance, it is not obvious at all what a nice and safe high-level API for wlroots should be (the current repo contains an attempt, but I think it needs to be reworked). See also for instance the difficulties that other people had when writing rust wrappers (http://way-cooler.org/blog/2019/04/29/rewriting-way-cooler-in-c.html).
Then, there's also the usual grunt work of writing the wrapper code itself.

And all of this only makes sense to in the end use the bindings to write a compositor (even a minimal one to start with), and coming up with something interesting is a project on its own.

So yeah, I guess the status is "experimental" and "hibernating" :-).

[wilhelmy]

The reason I'm asking is because I'm interested in writing a compositor, but I can't promise I can deliver a good one because that would stress me out, and I also have to worry about work for now. Would it be possible to generate part of the bindings and write a nice ocaml'y interface on top of that?

Edit: You could try outsourcing some of this to a capable student via GSoC, perhaps.

[wilhelmy]

I've seen some recent activity and became curious.

fukushima ~/s/wlroots-ocaml & dune external-lib-deps --missing '@@default'
Error: The following libraries are missing in the default context:
- xkbcommon
Hint: try: opam install xkbcommon
fukushima ~/s/wlroots-ocaml & opam install xkbcommon
[ERROR] No package named xkbcommon found.

Any ideas?

[Armael]

Yeah, you should pin my (at the moment unreleased) xkbcommon bindings:

opam pin add xkbcommon https://github.com/Armael/ocaml-xkbcommon

But yeah, I've been doing some cleanup. Now everything should compile, and the API now corresponds to "thin bindings": it sticks to the wlroots API as much as possible while being type safe.
This should make it easy to translate C code that uses wlroots into ocaml code using the bindings, and then start experimenting.

Still, there is a lot of mechanical work to be done to be able to implement nontrivial examples on top of the bindings. In particular, I started porting tinywl, but it is not complete and needs more work extending the bindings. Any help with that is welcome :).

[wilhelmy]

Hmmm... that doesn't work

fukushima ~/s/wlroots-ocaml & opam pin add xkbcommon https://github.com/Armael/ocaml-xkbcommon
Package xkbcommon does not exist, create as a NEW package? [Y/n] y
[xkbcommon.~dev] downloaded from https://github.com/Armael/ocaml-xkbcommon
[ERROR] Error getting source from https://github.com/Armael/ocaml-xkbcommon:
          - Unknown archive type: /tmp/opam-22413-1872ec/ocaml-xkbcommon

Thin bindings sound good. Building more ocaml-y bindings on top of that can always be done later. I'll take a more in-depth look and I'm aware that there's always mechanical work to be done for bindings. Thanks for your effort :)

[Armael]

Ah, try:

opam pin add xkbcommon https://github.com/Armael/ocaml-xkbcommon.git

[wilhelmy]

Thanks, that did the trick

[wilhelmy]

Got a build failure now:

[wlroots.~dev] no changes from git+file:///home/mw/src/wlroots-ocaml#master
The following actions will be performed:
  - install wlroots ~dev*
[wlroots.~dev] synchronised from git+file:///home/mw/src/wlroots-ocaml#master

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[ERROR] The compilation of wlroots failed at "/home/mw/.opam/opam-init/hooks/sandbox.sh build dune build -p wlroots -j 3 @install".

#=== ERROR while compiling wlroots.~dev =======================================#
# context     2.0.6 | linux/x86_64 | ocaml-system.4.10.0 | pinned(git+file:///home/mw/src/wlroots-ocaml#master#9642b0f0)
# path        ~/.opam/default/.opam-switch/build/wlroots.~dev
# command     ~/.opam/opam-init/hooks/sandbox.sh build dune build -p wlroots -j 3 @install
# exit-code   1
# env-file    ~/.opam/log/wlroots-25534-dc6e87.env
# output-file ~/.opam/log/wlroots-25534-dc6e87.out
### output ###
# [...]
# File "_none_", line 1:
# Warning 58: no cmx file was found in path for module Time_unix, and its interface was not compiled with -opaque
#       ocamlc lib/generated_ffi_stubs.o (exit 2)
# (cd _build/default/lib && /usr/bin/ocamlc.opt -g -I /home/mw/.opam/default/lib/bytes -I /home/mw/.opam/default/lib/ctypes -I /home/mw/.opam/default/lib/integers -I /home/mw/.opam/default/lib/mtime -I /home/mw/.opam/default/lib/mtime/os -I /home/mw/.opam/default/lib/result -I /home/mw/.opam/default/lib/unix-errno -I /home/mw/.opam/default/lib/unix-time -I /home/mw/.opam/default/lib/xkbcommon -[...]
# generated_ffi_stubs.c: In function ‘wlroots_stub_24_wlr_renderer_init_wl_display’:
# generated_ffi_stubs.c:174:17: error: void value not ignored as it ought to be
#   174 |    _Bool x102 = wlr_renderer_init_wl_display(x100, x101);
#       |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
# generated_ffi_stubs.c: In function ‘wlroots_stub_25_wlr_keyboard_set_keymap’:
# generated_ffi_stubs.c:181:17: error: void value not ignored as it ought to be
#   181 |    _Bool x107 = wlr_keyboard_set_keymap(x105, x106);
#       |                 ^~~~~~~~~~~~~~~~~~~~~~~



<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+- The following actions failed
| - build wlroots ~dev
+- 
- No changes have been performed

[Armael]

Do you have the latest version of wlroots (from their git)?

[wilhelmy]

Nope, but I didn't know you're targeting their git master instead of release. I have 0.10.1. I can check with master later. (Maybe all this should go into README.md?)

[Armael]

Yeah, all of this should definitely go in the readme. I think at targeted the release branch at some point, and ended up installing the git version for other purposes, and didn't checked whether it broke.

For now let's just say I target the git master yeah :/.

[wilhelmy]

No worries, it's not like I'm expecting a finished product ;)

[wilhelmy]

I'm messing around with it a little bit (I've never really used OCaml, only SML) and I'm stuck at writing a .merlin file for the tinywl subdir. Sorry to bum so much support off you, but I looked at the other .merlin files and there's numbers and underscores that I don't understand. Do you generate them somehow?

[Armael]

Yeah you shouldn't have to write .merlin files by hand, dune generates them automatically. So if you build tinywl (dune build tinywl/tinywl.exe or just make examples) then that will generate the .merlin files, and merlin should provide you with type information.