Re: why chords with notes of different duration is not supported?

[David Kastrup]

Graham Percival <address@hidden> writes:

> On Fri, Jan 14, 2011 at 09:58:15PM +0000, Neil Puttock wrote:
>> On 14 January 2011 21:04, David Kastrup <address@hidden> wrote:
>> 
>> > Sometimes I am inclined to just commit and be done.  After all, this
>> > would just omit a warning in working cases, and would fix the totally
>> > broken warning message when breves and longas get into play.  Of course,
>> > this latter part would require translations of the fixed message to be
>> > placed in the message catalogs.
>> 
>> It looks fine to me, apart from a whitespace nitpick.  The only thing
>> missing is a regtest.
>
> Why a regtest?  I mean, would what it check...?  would it just be
> verifying that lilypond doesn't print a message in this particular
> case?  At the moment we don't have a (good) infrastructure for
> such regtests, but I hope to get that into play after 2.15.

And that the message gets more useful once \breve and \longa come into
play.

Anyway, I am currently confused about what engraver/settings are
responsible for what kid of operation.  This particular case would
seemingly just cover

a) putting several noteheads on a common compatible stem

which works for chording quarter notes with half notes.

It would apparently not help with

b) putting several noteheads on a common incompatible stem

which would be required for chording eighth notes with half notes

or any kind of

c) merging incompatible noteheads as long as the stem is incompatible

which is required for identical-sounding concurrent notes with different
durations, indicated for example by having just a half-note head on an
eighth-note stem (I think that the head-collision logic caters for that
subcase already, with several options).

I think I want at least b) in place before I call it a feature rather
than something working by accident.

So the calls for regtests at least had the advantage of me trying a few
other things and getting surprised.

-- 
David Kastrup