Create a \tuplet function to complement \times and tupletSpannerDuration

Create a \tuplet function to complement \times and tupletSpannerDuration

Here is its DOC string:

Scale the given @var{music} to tuplets.  @var{ratio} is a
fraction that specifies how many notes are played in place of the
nominal value: it will be @samp{3/2} for triplets, namely three notes
being played in place of two.  If the optional @var{duration} is
specified, it is used for initializing @code{tupletSpannerDuration}.
For example,
@example
\tuplet 3/2 4 { c8 c c c c c }
@end example
will result in two groups of three tuplets, each group lasting for a
quarter note.  The value of @code{tupletSpannerDuration} is retained
as default if it is set in this manner.  Clearing it can be achieved
by specifying @samp{1*0} as @var{duration}.

Also:
Let input/regression/auto-beam-tuplets.ly use \tuplet


There has been an extensive discussion about the tuplet project on the
developer mailing list.  To be honest, I don't remember the details
but it would appear that nothing that actually entered LilyPond came
of it.  So let's get the ball rolling again.

[lemzwerg, 2013-01-10 04:57:14]

LGTM.

[Trevor Daniels, 2013-01-10 10:34:06]

LGTM

[dak, 2013-01-10 19:30:47]

Fix comment problem

[benko.pal, 2013-01-10 22:21:23]

good for a start but I have some problems with the duration parameter:

1.
{
  \tuplet 3/2 { c8 c c c c c }
  \tuplet 3/2 4 { c8 c c c c c }
  \tuplet 3/2 { c8 c c c c c }
}

I found it ugly that the first and last input line are engraved differently
(i.e. duration has an effect outside of its tuplet);

2. it works funny in scaled music (e.g. nested tuplets):

  \tuplet 3/2 { c4 \tuplet 3/2 4 { c8 c c c c c } }

[dak, 2013-01-10 22:40:03]

On 2013/01/10 22:21:23, benko.pal wrote:
> good for a start but I have some problems with the duration parameter:
> 
> 1.
> {
>   \tuplet 3/2 { c8 c c c c c }
>   \tuplet 3/2 4 { c8 c c c c c }
>   \tuplet 3/2 { c8 c c c c c }
> }
> 
> I found it ugly that the first and last input line are engraved differently
> (i.e. duration has an effect outside of its tuplet);

For the rationale, see the Google tracker issue description.  I picked one of
several possible behaviors.  The one that I picked has the advantage to make it
reasonably straightforward to have a working convert-ly rule matching current
use cases, and it is often convenient in saving typing work.

The alternative would be _unsetting_ at the end of a \tuplet with given
duration, regardless of whether the value was set previously.

> 2. it works funny in scaled music (e.g. nested tuplets):
> 
>   \tuplet 3/2 { c4 \tuplet 3/2 4 { c8 c c c c c } }

No good idea how to work this one reasonably since tupletSpannerDuration is
being set permanently.  Maybe one should scrap tupletSpannerDuration altogether
and just encode the duration straight into the event?  That's where it ends up
anyway.  Huh, or keep tupletSpannerDuration around but ignore it when the event
specifies a duration itself.

Again, bad for convert-ly rules, but probably cleaner.

[Trevor Daniels, 2013-01-10 23:40:25]

On 2013/01/10 22:40:03, dak wrote:
> No good idea how to work this one reasonably since tupletSpannerDuration is
> being set permanently.  Maybe one should scrap tupletSpannerDuration
altogether
> and just encode the duration straight into the event?  That's where it ends up
> anyway.  Huh, or keep tupletSpannerDuration around but ignore it when the
event
> specifies a duration itself.

I would prefer the last suggestion: keep tupletSpannerDuration to
specify the current default for duration, overriding it when
a duration is specified in the event, i.e. as an optional
argument to the \tuplet function.  That sounds logical, easy
to explain and document, and answers Pal's points.

[Ian Hulin (gmail), 2013-01-11 16:27:24]

Hi David,

Thanks for spotting this may get lost.  Actually getting this one finished after
all the [talk] and [proposal] discussions was first on my list of things to do,
but I have had to spend the holiday period in hospital, with access to only half
of of my e-mails etc. I've only got access to all the discussion here on my
computer at home.  

I'd like to cook a patch that captures where I thought we'd got to, and send it
to you as a formatted patch file.

Please have a look at it, I'll create the tracker issue, and we'll sort the
paperwork out. Sorry for dropping the ball on this one.

Cheers,
Ian

[Ian Hulin (gmail), 2013-01-11 16:46:19]

Hi David,

Please ignore most of my last post.  It looks like you're doing stage one of
what the [talk] [proposal] stuff was about.  

Many thanks,
Ian

[Ian Hulin (gmail), 2013-01-11 18:28:35]

I don't think \tuplet needs the tupletSpannerDuration property. Do it all
in-line using the optional @var{duration} parameter.  (Maybe call this
spanner-duration). See comments below.

Cheers,

Ian

https://codereview.appspot.com/7058068/diff/4/ly/music-functions-init.ly
File ly/music-functions-init.ly (right):

https://codereview.appspot.com/7058068/diff/4/ly/music-functions-init.ly#newc...
ly/music-functions-init.ly:1344: being played in place of two.  If the optional
@var{duration} is
If the optional @var{duration} parameter is specified, this is used to have the
tuplet use spanner brackets differing from the total length of the music in the
tuplet. Typically this could be used to specify a group of subdivisions within
the tuplet.
For example,

https://codereview.appspot.com/7058068/diff/4/ly/music-functions-init.ly#newc...
ly/music-functions-init.ly:1351: quarter note.  The value of
@code{tupletSpannerDuration} is retained
Cut out these sentences
"The value of @code{tupletSpannerDuration} is retained as default if it is set
in this manner. Clearing it can be achieved by specifying @samp{1*0} as
@var{duration}"

https://codereview.appspot.com/7058068/diff/4/ly/music-functions-init.ly#newc...
ly/music-functions-init.ly:1372: 
Get rid of code doing things to tupletSpannerDuration.  I think this property
was a kludge they put in because you couldn't code an optional parameter when
the old \times commands was written.
Look at the NR example for tupletSpannerDuration:

{
  \set tupletSpannerDuration = #(ly:make-moment 1 4)
  \times 2/3 { c8 c c c c c }
}

WDYT?

Cheers,

Ian

[dak, 2013-01-11 20:58:11]

Ok, most of this is obsolete due to myself not managing reviews properly.  The
current review for issue 3095 is to be found at
<URL:http://codereview.appspot.com/7094044>.  I am closing this one down. 
Apologies.

On 2013/01/11 18:28:35, Ian Hulin (gmail) wrote:
> I don't think \tuplet needs the tupletSpannerDuration property. Do it all
> in-line using the optional @var{duration} parameter.  (Maybe call this
> spanner-duration). See comments below.

See current patch: tupletSpannerDuration is not touched.  It is only used when
the optional duration argument is not given.  If one wanted to rename the
duration argument, in line with the current proposal it would likely best be
named tuplet-span .

> https://codereview.appspot.com/7058068/diff/4/ly/music-functions-init.ly
> File ly/music-functions-init.ly (right):
> 
>
https://codereview.appspot.com/7058068/diff/4/ly/music-functions-init.ly#newc...
> ly/music-functions-init.ly:1344: being played in place of two.  If the
optional
> @var{duration} is
> If the optional @var{duration} parameter is specified, this is used to have
the
> tuplet use spanner brackets differing from the total length of the music in
the
> tuplet. Typically this could be used to specify a group of subdivisions within
> the tuplet.
> For example,
> 
>
https://codereview.appspot.com/7058068/diff/4/ly/music-functions-init.ly#newc...
> ly/music-functions-init.ly:1351: quarter note.  The value of
> @code{tupletSpannerDuration} is retained
> Cut out these sentences
> "The value of @code{tupletSpannerDuration} is retained as default if it is set
> in this manner. Clearing it can be achieved by specifying @samp{1*0} as
> @var{duration}"

Isn't there in the current version.

>
https://codereview.appspot.com/7058068/diff/4/ly/music-functions-init.ly#newc...
> ly/music-functions-init.ly:1372: 
> Get rid of code doing things to tupletSpannerDuration.  I think this property
> was a kludge they put in because you couldn't code an optional parameter when
> the old \times commands was written.
> Look at the NR example for tupletSpannerDuration:
> 
> {
>   \set tupletSpannerDuration = #(ly:make-moment 1 4)
>   \times 2/3 { c8 c c c c c }
> }
> 
> WDYT?

Well, the last proposal is pretty much already where you wanted it to be.  Check
out the above named Rietveld report, and sorry for starting so many of them. 
One of them was a git-cl problem.