Re: How hard is something like CADB to do?

[David Kastrup]

David Kastrup <address@hidden> writes:

> CADB is sort of an international standard for transcribing diatonic
> accordion music.  It consists of regular notes on one system, with
> basically numbers arranged according to what button to press or pull in
> another system below, then chords under that.
>
> An explanation of the notation can be found at
> <URL:http://www.diato.fr/exptab2.htm>.  The same site has example
> scores, like <URL:http://www.diato.fr/tablat/tab108.png>.

[...]

> So the problems boil down to
>
> a) the graphical representation (which requires fixed vertical space and
> not normally additional horizontal space)
>
> b) some sort of fingering engine which one can feed the necessary
> information for choosing its priorities
>
> How would one go about implementing something like that in lilypond?
> How would the work get structured?  What would require working on the
> kernel, what on subsystems?  How well can the subsystems be separated?
>
> How much intelligence can one reasonably program into the fingering
> engine without having it explode in complexity?  It is thinkable to
> tell it something like TeX's "badnesses" as overall penalties for
> changing rows, changing bellows direction, and then let it minimize
> over that?
>
> Or have a draft mode where, say, one has it pick one fingering
> according to explicit priorities and indicate alternative fingerings
> in different markup (small print, in parens or something), so that one
> can incrementally override bad automatically chosen fingerings until
> arriving at a good solution, in sort of a feedback loop?
>
> Ok, but that's basically icing.  The main question is how hard it would
> be to have it do the basic notation.

Uh, this was not a feature request.  It was a request to the people who
have actually implemented stuff in Lilypond to give me a sketch of the
necessary work to be done, and in what areas they would need to be done,
and how well-prepared Lilypond is for doing such things.

It was also a question about how well-prepared Lilypond is for embedding
algorithms for what amounts to fingering instructions (converting to any
kind of tablature has this problem: the more sparingly you can use
hints for generating instrument-specific instructions, the better).

So it's basically just a minute job on some questions.  They are just
questions.  Just fire away, no preparation needed, no code.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum