Re: [frogs] Da Capos, Codas and Segnos

[Marc Hohl]

David Kastrup schrieb:
> Marc Hohl <address@hidden> writes:
>
>   
> > After reading through the other posts, I think that overloading
> > \repeat would not cover *all* possible
> > cases. On the other hand, there should be *one* consistent way of
> > doing any kind of repeats.
> >
> > David's comparison with goto-like structures seems to be the right
> > approach, so I revert my
> > proposal about enhancing \repeat for a more universal structure.
> >     
>
> Oh I think we are not communicating.  I liked your proposal quite well,
> even though it did not cover "everything conceivable".
>   
Oh, obviously I misunderstood your remarks.
> What I was talking about that in order not to have a proliferation of
> things that work/expand with only a subset of the supported repeats,
> that the internal music data structures gain a few "linkages" or
> whatever you want to call it that cover the possible sequencing.
>
> For example, one could have an element "multibranch" that contains a
> sequence of music list tails (or #t to continue on the printed score).
> When this element is passed/played the first time, it takes the first
> branch, then the next...  It should be reasonably easy to perform this
> with this info, and reasonably easy to produce the right amount of
> preannounce material.  Doing cautionary accidentals correctly needs the
> reverse information, namely instead of "where can I be going to from
> here" the info "where can I be coming from here".
>
> But the point is that "repeat volta" and "coda" and whatever else in the
> music list should be just interesting for the grob engraver, and
> performer and repeat unfolder and cautionaries and stuff get their info
> from a lower-level primitive data structure.
>   
I agree. So We need both a data structure flexible enough to cover
all possible cases, and an input mechanism which is consistent and
yet not overwhelmingly complicated from the user's view.
> Like a compiler compiling conditionals to jnz, the high level language
> with which we specify the structures should be powerful enough to avoid
> the explicit use of "goto" whenever possible.
>
> But there might be some user-level description of the logical structure
> that can get by without use of "goto" at the input level, even though it
> may get compiled to such.
>   
In principle, I second this. A perfect implementation should (at least 
in my opinion)
make the input source nearly as readable and understandable as the 
musical output,
so perhaps structuring the input file with

\coda {
...
}

\trio {
...
}

and some \toCoda/\toTrio commands might be necessary, though.

Greetings,

Marc