On Thu, Jul 5, 2012 at 12:37 AM, address@hidden
<mailto:address@hidden> <address@hidden
<mailto:address@hidden>> wrote:
On 4 juil. 2012, at 20:10, Marc Hohl wrote:
> Am 04.07.2012 13:29, schrieb David Kastrup:
>> Marc Hohl <address@hidden <mailto:address@hidden>> writes:
>>
>>> Hello list,
>>>
>>> the topic is somewhat over my head, but perhaps someone with more
>>> insight can answer this question?
>> I think that gcc likely can, don't know about g++, and we don't
want to
>> rely on it anyhow.
> Ok.
>
> Well then, is there an alternative?
>
> I want to get rid of bar-line.cc (issue 1320), and I have
managed to get all
> definitions but Bar_line::non_empty_barline into scheme.
>
> In lily/note-spacing.cc, I have
>
> Grob *bar = Pointer_group_interface::find_grob (right_col,
> ly_symbol2scm ("elements"),
> Bar_line::non_empty_barline);
>
> The simple approach
>
> bool non_empty_barline =
> ly_scm2bool (scm_call_1 (ly_lily_module_constant
("bar-line::non-empty-barline"), right_col->self_scm ()));
>
> with
>
> (define-public (bar-line::non-empty-barline grob)
> (and (grob::has-interface grob 'bar-line)
> (pair? (ly:grob-extent grob grob X))))
>
> doesn't work.
>
I just realized that there's an easier way to do this w/ existing
code conventions. You can overload
Pointer_group_interface::find_grob so that it accepts a simple
closure as the third argument. Then, wrap the Scheme function in
a simple closure.
Why not just leave the function in C++? I have nothing against porting
things to scheme, but in this case it just seems like an exercise in
making things more complicated, for no gain.