Sets spanner length as a spanner property.

Sets spanner length as a spanner property.

[MikeSol, 2011-06-30 14:21:00]

Hey all,

This patch simplifies a lot of code duping I'm doing to get spanner lengths in
various scheme functions.  Please lemme know if it's OK!

Cheers,
MS

[MikeSol, 2011-06-30 14:32:36]

On 2011/06/30 14:21:00, MikeSol wrote:
> Hey all,
> 
> This patch simplifies a lot of code duping I'm doing to get spanner lengths in
> various scheme functions.  Please lemme know if it's OK!
> 
> Cheers,
> MS

And it breaks the build of internals.texi on my machine...does anyone have any
ideas as to why this may be the case?  The change is pretty small, so hopefully
someone will spot it relatively quickly.

[Neil Puttock, 2011-06-30 14:52:04]

On 2011/06/30 14:32:36, MikeSol wrote:
> On 2011/06/30 14:21:00, MikeSol wrote:
> > Hey all,
> > 
> > This patch simplifies a lot of code duping I'm doing to get spanner lengths
in
> > various scheme functions.  Please lemme know if it's OK!
> > 
> > Cheers,
> > MS
> 
> And it breaks the build of internals.texi on my machine...does anyone have any
> ideas as to why this may be the case?  The change is pretty small, so
hopefully
> someone will spot it relatively quickly.

hyphen-length isn't documented.

[Neil Puttock, 2011-06-30 14:56:25]

http://codereview.appspot.com/4641085/diff/1/lily/spanner.cc
File lily/spanner.cc (right):

http://codereview.appspot.com/4641085/diff/1/lily/spanner.cc#newcode551
lily/spanner.cc:551: "length "
this conflicts with the current usage for Stem

[MikeSol, 2011-06-30 15:15:09]

On 2011/06/30 14:56:25, Neil Puttock wrote:
> http://codereview.appspot.com/4641085/diff/1/lily/spanner.cc
> File lily/spanner.cc (right):
> 
> http://codereview.appspot.com/4641085/diff/1/lily/spanner.cc#newcode551
> lily/spanner.cc:551: "length "
> this conflicts with the current usage for Stem

Fixed and fixed.

Cheers,
MS

[hanwenn, 2011-06-30 15:20:23]

On Thu, Jun 30, 2011 at 11:21 AM,  <mtsolo@gmail.com> wrote:
> Reviewers: ,
>
> Message:
> Hey all,
>
> This patch simplifies a lot of code duping I'm doing to get spanner
> lengths in various scheme functions.  Please lemme know if it's OK!

Why is length not computed as a callback?  You should avoid
set_property() as much as possible, since the order in which the code
calling set_property() is not defined. Hence, readers of the length
property cannot be sure that it has been set.

What calculations are simplified?  Can you include examples?  I am
sure that the lilypond code uses spanner length in a ~100 places or
so.  If you are starting to use a property for length, your code
should have a 100 places changed.

I think you scheme code will be easier to follow if you just define a
function that computes the length, if given a spanner.

--
Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

[mike_apollinemike.com, 2011-06-30 15:38:46]

On Jun 30, 2011, at 5:20 PM, Han-Wen Nienhuys wrote:

> On Thu, Jun 30, 2011 at 11:21 AM,  <mtsolo@gmail.com> wrote:
>> Reviewers: ,
>> 
>> Message:
>> Hey all,
>> 
>> This patch simplifies a lot of code duping I'm doing to get spanner
>> lengths in various scheme functions.  Please lemme know if it's OK!
> 
> Why is length not computed as a callback?  You should avoid
> set_property() as much as possible, since the order in which the code
> calling set_property() is not defined. Hence, readers of the length
> property cannot be sure that it has been set.
> 

There's no issue with computing this as a separate callback save the fact that
it'd result in a code dup with the normalized endpoints callback.

> What calculations are simplified?  Can you include examples?  I am
> sure that the lilypond code uses spanner length in a ~100 places or
> so.  If you are starting to use a property for length, your code
> should have a 100 places changed.
> 

This makes it easier to do manipulations on a line-breaking spanner whose
different pieces are not supposed to be copies of each other.

> I think you scheme code will be easier to follow if you just define a
> function that computes the length, if given a spanner.
> 

I have a version of this written in Scheme that I use in my graphical notation. 
I'll throw up a new patch with this in the not-too-distant future.  But, again,
it is a code dup from the normalized endpoints callback, which can calculate
both spanner length and normalized endpoints in one fell swoop (at the expense
of using set_property).

Cheers,
MS

[Colin Campbell, 2011-07-01 02:33:55]

Addewd as issue 1729