Re: Why no review on Doc: NR 1.6.2 - Staff Symbol?

[David Kastrup]

Graham Percival <address@hidden> writes:

> On Sat, Dec 03, 2011 at 03:02:42PM +0000, Carl Sorensen wrote:
>> On 12/3/11 7:38 AM, "David Kastrup" <address@hidden> wrote:
>> 
>> >James <address@hidden> writes:
>> >
>> >> Nothing sinister about it, and am happy to revert it but don't
>> >> understand why this is bad. Sure the new example is much 'simpler'
>> >> than having  write all the \new Staff { with }, especially when I as a
>> >> LP user want to write single system scores where I would probably
>> >> never ever use \new Staff { \with.
>> >
>> >You apparently did not read what I wrote.  The new example _does_ _not_
>> >_work_ in standalone contexts.
>> 
>> Actually, if you follow the instructions in the Learning Manual, it _does_
>> work.
>> 
>> See the Learning Manual, section 1.4.1 Omitted material, which explains
>> that snippets from the documentation need to be enclosed in {} or
>> \relative {}.
>
> For the record, I discussed this with James (a month or two ago?),
> and suggested removing the \with for exactly this reason.

You did read the passage from this section which I quoted which
explicitly said that this was intended for stuff you would copy and
paste within other music material?

>> >And anyway, using music overrides instead of context modifications is
>> >_asking_ _for_ _trouble_ here since the overrides take only effect at a
>> >certain _musical_ moment.  And that moment may already be too late for
>> >proper typesetting.
>
> I honestly have no clue what you're talking about.  As the doc
> editor since 2003, I don't know what the difference is between
> music overrides and context modifications.

A context modification is valid for the _lifetime_ of a context.  The
effect of an override starts at the musical moment where it is
encountered in a music stream.  If you nest Staffs in a Staffgroup, all
Staff contexts are created at the earliest musical moment of _any_
Staff.  If that earliest moment is different for different Staffs (like
it can happen when you use \grace or \skip), a music \override does not
work.  In fact, the only reason it does work most of the time is because
in engraver-init.ly, Output_property_engraver is very early in the list
of engravers, before Staff_symbol_engraver and
Instrument_name_engraver.  But that does not help if
Output_property_engraver is called at a later musical moment than
Staff_symbol_engraver because the StaffGroup does not all start at the
same musical moment.

>> This argument seems to me to be the salient argument here.
>> Properties that should affect an entire context are better placed in
>> a context modification.
> ...
>> So I think I agree that the simplification should not be made.
>
> Ok.  James: please change this back.

It already never happened.

> Overall lesson: it seems that we should have reviews for more doc
> items than we did previously, since neither James nor I are
> qualified to deal with advanced lilypond concepts.

It is somewhat audacious to assume that a whole _feature_ exists for no
good reason.  And adding new information can always be improved later.
But throwing away or modifying old information when one does not even
understand what it was doing is a good reason to ask.

-- 
David Kastrup