Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:

> I was thinking about a match against key before (match value ...), which
> would then match value against a chosen predicate, and return an error
> if it doesn't match.
> ...

Could work, I'll see what I can do.  But first I'd like to know how to
actually add this to Guix! :)
Rebuild the world on core-updates or is there another way?

>>> The docstring may explain that, e.g., compound :mime-type key becomes
>>> MimeType.
>>
>> Hmm, OK but why?  The procedure produces the expected behaviour with
>> #:mime-type, is there anything else to clarify?
>
> As a packager, I need to know what key is going to produce
> StartupWMClass (note that :startup-wm-class produces, StartupWmClass, if
> that matters), or DBusActivatable. Unless I'm missing something, it is
> not obvious from the docstring.

I could be misunderstanding you.  The keys are self-documented like all
key arguments.  From any REPL / text editor, you would typically "show
the procedure arguments" to see what's available.  In Emacs/Geiser,
you can use Eldoc or completion to access the full list of key parameters.

-- 
Pierre Neidhardt
https://ambrevar.xyz/