Add means to display objects accessible from a grob

Add means to display objects accessible from a grob

A convenient means of displaying the grobs and grob-arrays pointed to by
various internal properties of a given grob would be very helpful for
debugging and development purposes.  For example, it would facilitate the
creation of advanced tweaks, which frequently require "lateral" access
to other grobs.

The output of the function 'grob::display-objects' shows all of the grobs
accessible to a given grob through ly:grob-object, along with the relevant
interfaces and properties.  It includes properties which are empty: not all
properties within an interface may be set for or used by a grob supporting
that interface.

[david.nalesnik, 2015-03-24 16:38:52]

Please review.  Thanks!

[thomasmorley651, 2015-03-24 21:58:28]

LGTM

One question:

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm
File scm/output-lib.scm (right):

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm#newcode165
scm/output-lib.scm:165: (use-modules (ice-9 pretty-print))
I always regretted that (ice-9 pretty-print) is not included per default. 
Is there any reason not to do so?

[david.nalesnik, 2015-03-25 00:15:45]

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm
File scm/output-lib.scm (right):

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm#newcode165
scm/output-lib.scm:165: (use-modules (ice-9 pretty-print))
On 2015/03/24 21:58:28, thomasmorley651 wrote:
> I always regretted that (ice-9 pretty-print) is not included per default. 
> Is there any reason not to do so?

It isn't loaded in scm/lily.scm where a number of basic modules are loaded. 
However, it is loaded in one of the first files in the load path:
scm/lily-library.scm.  This file is loaded even before this file, so I wonder if
I should consider my inclusion redundant.  In fact, (ice-9 pretty-print) is
included elsewhere, for example in scm/music-functions.scm--and it appears that
there are redundant inclusions of other modules elsewhere.  I wonder--is this
bad form?  Will it increase memory consumption?

Yet, why does the module need to be added in a ly file for pretty-print to be
defined?

[david.nalesnik, 2015-03-25 01:13:20]

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm
File scm/output-lib.scm (right):

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm#newcode165
scm/output-lib.scm:165: (use-modules (ice-9 pretty-print))
On 2015/03/25 00:15:45, david.nalesnik wrote:
> On 2015/03/24 21:58:28, thomasmorley651 wrote:
> > I always regretted that (ice-9 pretty-print) is not included per default. 
> > Is there any reason not to do so?
> 
> It isn't loaded in scm/lily.scm where a number of basic modules are loaded. 
> However, it is loaded in one of the first files in the load path:
> scm/lily-library.scm.  This file is loaded even before this file, so I wonder
if
> I should consider my inclusion redundant.  In fact, (ice-9 pretty-print) is
> included elsewhere, for example in scm/music-functions.scm--and it appears
that
> there are redundant inclusions of other modules elsewhere.  I wonder--is this
> bad form?  Will it increase memory consumption?
> 
> Yet, why does the module need to be added in a ly file for pretty-print to be
> defined?

Well, it's not much code of course.  Would it even be reloaded?  Anyway, I
wonder if "redundant" use-modules invocations should be removed, or at least
reduced to comments.

[ul_openlilylib.org, 2015-03-25 05:35:28]

>Well, it's not much code of course.  Would it even be reloaded? 
>Anyway,
>I wonder if "redundant" use-modules invocations should be removed, or
>at
>least reduced to comments.

Scheme modules are loaded only once so thee is no overhead involved.

>
>https://codereview.appspot.com/217260043/
>
>_______________________________________________
>lilypond-devel mailing list
>lilypond-devel@gnu.org
>https://lists.gnu.org/mailman/listinfo/lilypond-devel

[david.nalesnik, 2015-03-25 13:59:20]

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm
File scm/output-lib.scm (right):

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm#newcode165
scm/output-lib.scm:165: (use-modules (ice-9 pretty-print))
On 2015/03/24 21:58:28, thomasmorley651 wrote:
> I always regretted that (ice-9 pretty-print) is not included per default. 
> Is there any reason not to do so?

Looks like all that needs to be done is to add
(use-modules (ice-9 pretty-print))
to ly/init.ly

Then, pretty-print is available to ly files, including within music functions.

Shall I submit a patch?

[david.nalesnik, 2015-03-25 14:11:34]

On 2015/03/25 05:35:28, ul_openlilylib.org wrote:
> 
> 
> >Well, it's not much code of course.  Would it even be reloaded? 
> >Anyway,
> >I wonder if "redundant" use-modules invocations should be removed, or
> >at
> >least reduced to comments.
> 
> Scheme modules are loaded only once so thee is no overhead involved.
> 
> >
> >https://codereview.appspot.com/217260043/
> >
> >_______________________________________________
> >lilypond-devel mailing list
> mailto:>lilypond-devel@gnu.org
> >https://lists.gnu.org/mailman/listinfo/lilypond-devel
> 

OK, so I may as well leave it as-is, especially as it's not part of the Guile
core.  (See
http://www.gnu.org/software/guile/docs/docs-1.8/guile-ref/SRFI_002d0.html#SRF...
.)

[pwm, 2015-03-26 01:15:52]

LGTM

[thomasmorley651, 2015-03-27 01:12:15]

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm
File scm/output-lib.scm (right):

https://codereview.appspot.com/217260043/diff/1/scm/output-lib.scm#newcode165
scm/output-lib.scm:165: (use-modules (ice-9 pretty-print))
On 2015/03/25 13:59:20, david.nalesnik wrote:
> On 2015/03/24 21:58:28, thomasmorley651 wrote:
> > I always regretted that (ice-9 pretty-print) is not included per default. 
> > Is there any reason not to do so?
> 
> Looks like all that needs to be done is to add
> (use-modules (ice-9 pretty-print))
> to ly/init.ly
> 
> Then, pretty-print is available to ly files, including within music functions.
> 
> Shall I submit a patch?


Yes, would be great.