GOOPS-less Shepherd

[Ludovic Courtès]

Hello!

I’d like to release the Shepherd 0.10.0 in a few weeks at most, with the
hope that it’ll be the last stable series before 1.0, which would be
released in a few months.

As part of this, I’d like to clean up the API, which includes removing
the dependency on GOOPS.  The Shepherd had been using GOOPS from the
start but for no particular reason: there’s no inheritance and only a
couple of cases of method overloading.

I started that work, which mostly involves renaming things like
accessors following typical Scheme conventions:

  https://git.savannah.gnu.org/cgit/shepherd.git/log/?h=wip-goopsless

I imagine the following deprecation scenario:

  • 0.10.x would still support GOOPS, as in (make <service> …), but
    that would be deprecated in favor of a more Schemey (service …)
    form.  Under the hood it’s still GOOPS.

  • 1.0.x would no longer use GOOPS at all.  We could provide a ‘make’
    macro so that (make <service> …) would still kinda work.

What’s at stake, mostly, is the ability to reconfigure a long-running
shepherd instance.  Once 1.0.x is in Guix, ‘guix system reconfigure’
will most likely fail to upgrade services on a pre-0.10.x shepherd:
users will have to reboot.

Thoughts?

Ludo’.