Re: Context paths (and the Edition Engraver)

[Dan Eble]

On Jan 21, 2020, at 11:31, Jan-Peter Voigt <address@hidden> wrote:
> I'd like that, though it would be a quite invasive change.
> And if we stay with the string for the context id and then use
> lists/paths in the \context statement like
> \new Staff = "choir" << \new Voice = "soprano" …
> 
> and then use
> \context Voice = choir.soprano
> 
> it would be inconsistent with \new <Context> = "…"
> 
> I will write down some more text about this topic later.

I see similarities with languages like CSS and XPATH select nodes in a DOM.  
Notation borrowed directly from them will not integrate well into LilyPond, but 
it might be fruitful to ask how we could modify expressions like these to fit 
in.

    %% find the voice in the example quoted above, very specifically
    \context Staff#choir > Voice#soprano { … }         % CSS
    \context Staff[@id=choir]/Voice[@id=soprano] { … } % XPATH

    %% ditto, but using context type only
    \context Staff > Voice { … }                       % CSS
    \context Staff/Voice { … }                         % XPATH

    %% ditto, but using ID only
    \context #choir > #soprano { … }                   % CSS
    \context [@id=choir]/[@id=soprano] { … }           % XPATH

    %% find the context where the rehearsalMark property is defined
    \context [rehearsalMark] { … }                     % CSS
    \context [@rehearsalMark] { … }                    % XPATH
— 
Dan