Re: tag and default

[Gianmaria Lari]

On 12 April 2018 at 14:16, David Kastrup <address@hidden> wrote:

Gianmaria Lari <address@hidden> writes:

> On 12 April 2018 at 11:42, David Kastrup <address@hidden> wrote:
>>
>> What are you trying to do?  Basically you are asking whether you can
>> make LilyPond do something different without telling it to make
>> something different.
>>
>> You will need to provide more details of just what you want to be
>> providing via which channels and what not in order to have people figure
>> out what would better meet your requirement than just writing
>> \keepWithTag when you want it.
>
>
> 1) If it seemed I was complaining about lilypond behavior my
> apologies, not at all.

It did not seem like that to me and LilyPond won't heed complaints
anyway.

> 2) I paid much attention writing my question but, again my apologies,
> it was not clear.

The question was clear but it was not clear which leap of logic was to
be assumed for answering it.

> Let me try again with a different example.
>
> Sometimes I have an excerpt of music that occurs multiple time in a piece.
> It occurs identically in many place except at the end of the score where
> the last note of the excerpt should be a pause (it is just an example).
> Without tag I would do something like this:
>
> excerpt  = {a b c' d'}
> excerptB = {a b c' r}
> {
>  % .... some music
>  \excerpt
>
>  % .... some music
>  \excerpt
>
>  % .... some music
>  \excerptB
> }
>
>
> If I want to write the same thing with tag I would write:
>
> \version "2.19.81"
> excerpt  = {
>   a b c'
>     \tag #'withd d'
>     \tag #'withr r
> }
>
> {
>  % .... some music
>  \keepWithTag #'withd \excerpt
>
>  % .... some music
>  \keepWithTag #'withd \excerpt
>
>  % .... some music
>  \keepWithTag #'withr \excerpt
> }
>
>
> This is ok.
>
> Is there any way to obtain the same thing writing:
>
> {
>  % .... some music
> \excerpt
>
>  % .... some music
>  \excerpt
>
>  % .... some music
>  \keepWithTag #'withr \excerpt
> }

You probably would not stand for

{
  \keepWithTag #'withd {
     % .... some music
     \excerpt

     % .... some music
     \excerpt
     % .... some music
   }
   \keepWithTag #'withr \excerpt
}

so your question amounts to some stuff autosuiciding.  That's not really
something the tag system will do, but you may want to look at \pushToTag
and \appendToTag for some option of adding material only in specific
cases.

Ok. I had seen the \pushToTag and \appendToTag example in the manual. But I didn't understand the example. They are too complex for me.

Anyway, I found a nice escamotage that probably it solves my problem. I put here in case other need.

This was the original code:

\version "2.19.81"

excerpt  = {

  a b c' 

    \tag #'withd d'

    \tag #'withr r

}

{

 \keepWithTag #'withd \excerpt

 \keepWithTag #'withd \excerpt 

 \keepWithTag #'withd \excerpt 

 \keepWithTag #'withr \excerpt

}

And this is my solution:

\version "2.19.81"

music = { a b c' \tag #'lastnote d'}

{

  \music

  \music

  \music

  \removeWithTag #'lastnote \music r

}

Thank anyway!

g.