Bump Rustler to 0.34.0 in Cargo.toml (not 0.35.0), IOW, downgrade in mix.exs

[takasehideki]

This PR is trying to bump Rustler in Cargo.toml to 0.35.0. Also see #68
Note that this is now working in progress, since we are trying to bump it step by step by referring upgrade guide of Rustler.

---

As a result, we decided to bump Rustler in Cargo.toml to 0.34.0, not 0.35.0, in this PR.
The bump to 0.35.0, the current latest version, will be made after Zenoh's update to v1.0.0 first (#59), and then continued in #68.

[takasehideki]

I have confirmed that bump to 0.34.0 works fine. However, some warnings have occurred.
I think these should be eliminated.

   Compiling zenohex_nif v0.3.0 (/home/takase/zenoh/zenohex/native/zenohex_nif)
warning: use of deprecated constant `rustler_init::explicit_nif_functions`: Passing NIF functions explicitly is deprecated and this argument is ignored, please remove it
  --> src/lib.rs:59:5
   |
59 | /     [
60 | |         zenoh_open,
61 | |         session::declare_publisher,
62 | |         session::declare_subscriber,
...  |
83 | |         keyexpr::key_expr_intersects,
84 | |     ],
   | |_____^
   |
   = note: `#[warn(deprecated)]` on by default

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:46:5
   |
46 |     rustler::resource!(SessionRef, env);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: `#[warn(unused_must_use)]` on by default
   = note: this warning originates in the macro `rustler::resource` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:47:5
   |
47 |     rustler::resource!(PublisherRef, env);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: this warning originates in the macro `rustler::resource` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:48:5
   |
48 |     rustler::resource!(SubscriberRef, env);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: this warning originates in the macro `rustler::resource` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:49:5
   |
49 |     rustler::resource!(PullSubscriberRef, env);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: this warning originates in the macro `rustler::resource` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:50:5
   |
50 |     rustler::resource!(QueryableRef, env);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: this warning originates in the macro `rustler::resource` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:51:5
   |
51 |     rustler::resource!(ReplyReceiverRef, env);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: this warning originates in the macro `rustler::resource` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:52:5
   |
52 |     rustler::resource!(QueryRef, env);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: this warning originates in the macro `rustler::resource` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:53:5
   |
53 |     rustler::resource!(SampleRef, env);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: this warning originates in the macro `rustler::resource` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: `zenohex_nif` (lib) generated 9 warnings
    Finished `release` profile [optimized] target(s) in 3m 37s
Generated zenohex app

[takasehideki]

I guess the resource registration method may be changed, but cannot find how to upgrade,,,
https://docs.rs/rustler/0.34.0/rustler/macro.resource.html

[takasehideki]

With the help of the following various information, I have made modifications to 1b87285.
https://docs.rs/rustler/0.34.0/rustler/macro.resource.html
rusterlium/rustler@rustler-0.33.0...rustler-0.34.0#diff-77f824b36e0d96ba4f3fee0e86ff2edf9981f4c7df85c91ca8565683e2b2ba40
https://github.com/rusterlium/rustler/blob/master/rustler_tests/native/rustler_test/src/test_resource.rs

As a result, I succeeded in removing the compile-time warning message in Rustler 0.34.0.
However, I'm not at all confident that this modification is correct. Also, there exist the following discussion points:

---

I initially thought L55 in lib.rs should be written as follows.

    env.register::<SessionRef>().is_ok();

However, another warning message appeared.

warning: unused return value of `Result::<T, E>::is_ok` that must be used
  --> src/lib.rs:55:5
   |
55 |     env.register::<SessionRef>().is_ok();
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: if you intended to assert that this is ok, consider `.unwrap()` instead
   = note: `#[warn(unused_must_use)]` on by default
help: use `let _ = ...` to ignore the resulting value
   |
55 |     let _ = env.register::<SessionRef>().is_ok();
   |     +++++++

By following this, I decided to write using unwrap(). Is it correct??

---

For now, we use nif_version_2_15.
https://github.com/biyooon-ex/zenohex/pull/69/files#diff-c00d7d7d793ec0cad40fc4996fdfcd165480b7caeb51839bf526104e5ff6e746R15

However, we have already used OTP 26, so I think it is better to use nif_version_2_16 or nif_version_2_17.
https://github.com/rusterlium/rustler?tab=readme-ov-file#supported-nif-version

[takasehideki]

@s-hosoai @pojiro If you have time, could you give me advice and/or your knowledge??

FYI, I have still encountered another issues compiling with Rustler 0.35.0,,,

[pojiro]

@takasehideki

I initially thought L55 in lib.rs should be written as follows.

You are right. You need to use them like followings,

fn load(env: Env, _term: Term) -> bool {
    env.register::<SessionRef>().is_ok()
        && env.register::<PublisherRef>().is_ok()
        && env.register::<SubscriberRef>().is_ok()
        && env.register::<PullSubscriberRef>().is_ok()
        && env.register::<QueryableRef>().is_ok()
        && env.register::<ReplyReceiverRef>().is_ok()
        && env.register::<QueryRef>().is_ok()
        && env.register::<SampleRef>().is_ok()
}

is_ok() returns boolean, it means register works fine.

ref. https://github.com/rusterlium/rustler/blob/rustler-0.35.0/rustler/src/resource/registration.rs#L129-L155

[takasehideki]

About NIF version, we concluded that using 2.15 is reasonable because this is the default version for Rustler we don't have aggressive reasons to use newer features of NIF and OTP.
To make a note about this, I added 5c0e197 and made #71.

[takasehideki]

@pojiro Thank you so much for your awesome comment!!
I modified code according to your suggestion.
23eb6aa

[takasehideki]

I'd like to conclude that bumping Rustler to 0.35.0 is not cost-effective and difficult at this time, and that a response to 0.34.0 is sufficient for this PR (now).

Bumping Rustler to 0.35.0 caused many inexplicable compile errors. I guess that these are probably due to that the transition from async-std to Tokio was not yet complete in Zenoh 0.11.0. I have experimentally tried Zenoh 1.0.0 along with Rustler 0.35.0; most of the errors seemed not appear at that time (although many other compile errors happened, so we will have to work on resolving them).

IOW, please review @s-hosoai if this PR is acceptable or not 🙏
If you agree on this, I will merge it and release Zenohex 0.3.1.

[s-hosoai]

@takasehideki Thank you for the PR. The modifications you made are fine.
Additionally, please update the Rustler version in mix.exs. If this PR is upgrading to v0.3.1, please adjust the version accordingly.

[takasehideki]

@s-hosoai sorry I can’t catch up what you want me to do,,,

Rustler in mix.lock has already bumped to 0.3.5 by dependabot. You mean this should adjust to 0.3.4? I agree with your this suggestion and will treat it.

zenohex/mix.lock

Line 23 in c3f45e7

"rustler": {:hex, :rustler, "0.35.0", "1e2e379e1150fab9982454973c74ac9899bd0377b3882166ee04127ea613b2d9", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:req, "~> 0.5", [hex: :req, repo: "hexpm", optional: false]}, {:toml, "~> 0.6", [hex: :toml, repo: "hexpm", optional: false]}], "hexpm", "a176bea1bb6711474f9dfad282066f2b7392e246459bf4e29dfff6d828779fdf"},

#61

Or you mean Zenohex should bump to 0.3.1 in this PR too? I don’t think so, The bump to this library itself should be treated in the separate PR like the below.
#52

[takasehideki]

Rustler in mix.lock has already bumped to 0.3.5 by dependabot. You mean this should adjust to 0.3.4? I agree with your this suggestion and will treat it.

I got it in e288e6c d64faa0 (force-pushed because I forgot to specify to rustler in Cargo.toml).

@s-hosoai could you review again??

[s-hosoai]

The intention was to lock the version to 0.34. Your fix is perfect!
I also agree with handling the Zenohex version upgrade in a separate PR.

[takasehideki]

go merging! I will create another PR to release Zenohex 0.3.1.