Re: partcombine and tag

[David Kastrup]

Gianmaria Lari <address@hidden> writes:

> I'm trying to understand how to use partcombine and tag and I don't
> understand why compiling the following code I obtain two measures
>
> 4 4 | 4
>
> instead of just one
>
> 4 4 4
>
> In the attached image the resulting score.
>
> Here it is the code.
> %%%
> \version "2.19.40"
>
> note = \partcombine {e'4} {\tag #'pdfOut c4 \tag #'midiOut c'4}

\partcombine runs and creates a common score.  Since none of the tags is
removed, the result contains both c4 and c'4.  This is stored in \note.

I don't remember: doesn't partcombine complain when given parts of
different length?

> music =
> {
>   \time 3/4
>   \note \note \note
> }

Here you put three instances in a row.


> \score
> {
>   \keepWithTag #'pdfOut \music

The \music has already been partcombined, so there are no traces of any
tags left any more.  \keepWithTag doesn't do a thing on music without
tags.

>   \layout {}
> }

Basically, you need to use the equivalent of \keepWithTag/\removeWithTag
_before_ running \partcombine.  Afterwards, you only have a combined
list of events without any tags left.

It would be nice if \partcombine were rewritten to run just-in-time.
The current implementation runs it when encountered, however.  Which
means that it also has no access to context properties and other
niceties.

-- 
David Kastrup