Add Platform methods for BSD distros

[tonchis]

No description provided.

[tonchis]

@jemc I made this a draft because I see there are many tasks in the CI failing and didn't wanna merge with a broken pipeline. The ubuntu and macOS builds are passing, but since this is a BSD specific change it'd be nice to see it passing on such machine.

[mneumann]

love it!

[jemc]

Yes, looks like we have multiple CI issues to address, both with an Alpine version upgrade and a Crystal version upgrade.

None of them are likely to be related to this PR.

I will aim to make time today to get the pipeline green again.

[jemc]

I have a PR that should hopefully resolve the breakages for the existing CI jobs.

I agree with you that it would be nice to have FreeBSD CI working.

In particular, we won't be able to run FreeBSD CI for any of the libraries unless/until we get it working here for the main Savi build.

I did some work on a FreeBSD CI job a while back, but it's currently commented out because it's not working. I believe the key obstacle was that I couldn't get the latest version of Crystal installed on the FreeBSD CI runner - the existing "FreeBSD port" was pinned to an older version.

@mneumann (who uses FreeBSD) may have ideas about how to get past that obstacle.

[jemc]

Looking at https://www.freshports.org/lang/crystal/ I see that it looks like it includes the latest Crystal version (1.5.0) so it may be doable now. I'll create another branch to try to get FreeBSD CI up and running.

[jemc]

The above mentioned PR is merged, and here's a working PR to add a FreeBSD CI job: #340

[jemc]

Here's a tiny stupid English nitpick:

Suggested change

	:: Returns `True` if the target platform uses a OpenBSD operating system.
	:: Returns `True` if the target platform uses an OpenBSD operating system.

[jemc]

I believe that of these four platforms are mutually exclusive, right?

If so, then I think a test like the following would be more robust, and cover more failure cases:

Suggested change

	if Platform.is_bsd (assert: (
	Platform.is_freebsd ||
	Platform.is_openbsd ||
	Platform.is_netbsd ||
	Platform.is_dragonfly
	))
	is_bsd U8 = if Platform.is_bsd (1 | 0)
	assert: is_bsd == U8[0] +
	if Platform.is_freebsd (1 | 0) +
	if Platform.is_openbsd (1 | 0) +
	if Platform.is_netbsd (1 | 0) +
	if Platform.is_dragonfly (1 | 0)

That is, this tests that exactly one of those specific BSD platforms is true if and only if the overall platform designation is BSD - and if it's not BSD, then none of them are true.

[jemc]

I've rebased this PR on latest main, which should resolve the CI failures.