On Fri, Apr 21 2017, Carlo Zancanaro wrote:
> I'll have a go at it later today and see what I can come up with. (I'm
> not very familiar with guile/scheme libraries, but I have played around
> a fair bit with macros.)

Well, it's been a lot longer than "later today", but better late than
never, I guess!

I've attached two patches, one of which is the definition of
define-service-type, and the other which is me changing the
exim-service-type definition to use it.

I made a decision to not try to generate a define-configuration form,
and instead just generate an "old-style" define-record-type for the
configuration. That's mostly just because I don't know how to write
something that works with define-configuration and it felt more
complicated to me. If someone else wants to do that (or help me to
understand it) I'd be supportive.

I'm not really promoting this as something that should be merged at the
moment, but I'm mostly just offering it as food for thought.

Carlo