Re: Percent repeats in lyrics causes error in 2.18.2

[David Kastrup]

Thomas Morley <address@hidden> writes:

> Am Mi., 8. Mai 2019 um 00:25 Uhr schrieb David Kastrup <address@hidden>:
>>
>> Thomas Morley <address@hidden> writes:
>
>> > I tried a quick adhoc coding.
>> >
>> > Works with \unfoldRepeats, regrettable prints nothing without it.
>> > I'd expect to see it at least one time printed without \unfoldRepeats.
>> >
>> > Anyway, here my coding so far, what do I miss?
>>
>> An iterator creator ?
>
> I've exactly zero experience with this topic.
>
> I tried to get some more info, we have:
> http://lilypond.org/doc/v2.19/Documentation/contributor-big-page.html#iterator-tutorial
>
> Which reads:
> "
> 10.10 Iterator tutorial
> TODO – this is a placeholder for a tutorial on iterators
> Iterators are routines written in C++ that process music expressions
> and sent the music events to the appropriate engravers and/or
> performers.
> See a short example discussing iterators and their duties in
> Articulations on EventChord.
> "
> Not that enlightening... Admittedly there a some more hints spread over CG.
> Though, right now I'm not even sure, if it's possible in scheme at all.
>
> Is there any scheme-example?

In scm/define-music-types.scm I read

    (RepeatedMusic
     . ((description . "Repeat music in different ways.")
        (types . (repeated-music))
        ))

so it would appear that the default iterator should actually work as
intended if you fill the expression in the usual way (element containing
the main stuff, elements containing the alternatives).  Unless
RepeatedMusic is not actually being used.  No idea.

-- 
David Kastrup