Re: The exact semantics of the new \new command?

[Graham Percival]

On 23-Apr-06, at 2:50 AM, Mats Bengtsson wrote:

> What, exactly, is the semantics of the \new <context> = <name> ...
> syntax? As far as I understood the discussion leading to this
> syntax, it should be equivalent to
> \context <context> = <name>
> if that context wasn't already created and it should
> issue a warning if the context already existed.

IIRC, it was decided that no warning would be issued.  This was to make 
the implementation easier; I believe that there was some mention of 
upcoming 3.0 syntax changes that would change \new and \context 
further, and thus it didn't make sense to spend a lot of effort on it 
right now.

> As the following example shows (and the last example in
> "More Stanzas", for example), what really happens is equivalent
> to \new <context>, i.e. you get a new instance of the context
> with some anonymous name. Also, no warning is issued.
>
> \version "2.8.0"
>
> \relative <<
>  \new Staff = FIRST \new Voice { c1^"in FIRST" }
>   % Should at least issue a warning:
>  \new Staff = FIRST \new Voice { e1 e^"2nd incarnation of FIRST" }
>  % Which of the above two will this one end up in?:
>  \context Staff = FIRST \new Voice { g1 g g^"back in FIRST" }
> >>

Disregarding the warning issue (in HWN's words, "Don't Do That"), this 
example works (if you rename the second FIRST to SECOND).

> It seems that whoever updated the examples such as the
> last example in "More Stanzas" rather had the impression
> that
> \new <context> = <name> ...
> will always be equivalent to
> \context <context> = <name> ...
> which clearly isn't the case, so this is a problem both
> in the implementation and the documentation and example
> files.

I didn't think that \new was the same as \context, but I also don't 
claim to fully understand this issue.  As far as I know, right now \new 
works well other than not giving warnings.

The issue with "More Stanzas" is that I was updating the docs during a 
music theory lecture, and (as always) I don't really know what I'm 
doing with vocal music.  The two
\new Lyrics = "mainlyrics"
are obviously a mistake.  I've changed the second one to \context, and 
it looks right to me.

Cheers,
- Graham