2016-11-30 23:31 GMT+01:00 Noeck <noeck.marb...@gmx.de>:
> Hi,
>
> I have one more question on this topic:
>
> How can I check whether a header field is present at all?
> (Or my main goal: how can I avoid that the code fails?)
>
> This works:
> \version "2.19.50"
> \header {
> title = "ABC"
> }
> \paper {
> oddFooterMarkup = #(module-ref $defaultheader 'title)
> }
> { a }
>
>
> This does not for obvious reasons:
> oddFooterMarkup = #(module-ref $defaultheader 'maintainer)
>
>
> Instead of putting all possible headers in a default header like
> maintainer = ##f
> I would like to check the presence, sth like this pseudocode:
>
> oddFooterMarkup = #(if (in? 'maintainer $defaultheader)
> (module-ref $defaultheader 'maintainer)
> "")
>
> Cheers,
> Joram
>
>
Hi Joram,
we have ly:modules-lookup with a possible optional argument. Resulting in:
(ly:modules-lookup (list $defaultheader) 'foo "xy")
If foo is found its value is returned otherwise "xy"
HTH,
Harm
_______________________________________________
lilypond-user mailing list
lilypond-user@gnu.org
https://lists.gnu.org/mailman/listinfo/lilypond-user
