Re: Suggestion: Keep original breaks

[Alexander Kobel]

On 11/27/2013 04:32 PM, Urs Liska wrote:
> Am 27.11.2013 16:25, schrieb Carl Sorensen:
> > On 11/27/13 8:04 AM, "David Kastrup" <address@hidden> wrote:
> >
> > > Urs Liska <address@hidden> writes:
> > > [...]
> > > > originalBreak =
> > > > #(define-music-function (parser location)()
> > > >    ( #{ \tag #'keep-original-breaks \break #} ))
> > > > [...]
> > If the general case were added, and a special include were included, then
> > it seems like we'd have both David's wish for keeping things general and
> > Urs's wish for having an easily-used tool for the specific use case.
>
> For me this sounds good.
> Requiring to write \include "original-breaks.ly" is significantly better
> than requiring to define the commands.
> But it would still need a separate switch, presumably through the
> command line.

I do not want to open a Pandora's box here... Just some thoughts:
Would it be easy to add commandline switches for
 - including files with LilyPond input at the very beginning of the 
"compilation unit"
 - inserting Lilypond input given as a commandline argument at the 
beginning of the document?
And would it be feasible to have the equivalent of the LaTeX commands 
\providecommand and \renewcommand and/or \if\defined?

I imagine commandlines like the following:
  lilypond --include-first=stylesheet1.ly piece.ly [equivalent to]
  lilypond --input='\include "stylesheet1.ly"' piece.ly
  lilypond --input='#(set-default-paper-size "a5")' \
           --input='#(set-global-staff-size 15.87)' piece.ly
and, eventually,
  lilypond --input='originalBreak = {}' piece.ly
where piece.ly contains an
  \include "original-breaks.ly"
which uses \providecommand instead of the Urs' above command to define 
\originalBreak. Or you could re-point a tag name to the actual tag which 
will be used in the score.

Even without the \providecommand and \if\defined functionality, this 
looks like a useful feature for commandline control of Lily's output. 
And of course I hope that "pretending" some lines in front of the actual 
input file should not be too complicated or intrusive to implement?


Best,
Alexander