Re: /etc shortcut

[Stephan Schöll]

ha, with german browser settings and calling
https://lilypond.org/doc/v2.23/Documentation/notation/substitution-function-examples
I get content, but with chapter number 5.6.2 AND: nothing about the \etc
shortcut on the page.

Am 01.05.2022 um 21:46 schrieb Stephan Schöll:
> Be aware that the documentation looks very different depending on the
> language headers the brower hands over to the documentation web server!
> Based in Switzerland according to my default browser settings I get the
> german documentation. And this documentation differs very much from the
> english version in section 3 in general. And section 3.4 is definitively
> different in content, 3.4.3. even doesn't exist. Not surprising that I
> didn't find anything in the docs... The same browser language-specific
> behaviour happens also in the command index
> https://lilypond.org/doc/v2.23/Documentation/notation/lilypond-command-index
>
> : In the german version no entry for \etc exists.
>
> In both cases I am looking at the 2.23.8 dev branch documentation.
>
>
> Am 30.04.2022 um 23:17 schrieb Jean Abou Samra:
> > Le 30/04/2022 à 22:44, Stephan Schöll a écrit :
> > > Hi everybody
> > >
> > > A few days ago Lukas-Fabian has pointed me to the existence of the /etc
> > > shortcut. It seems to me that this would easy a lot of everday work
> > > without any further Scheme skills (music-function-... ). Unfortunately
> > > the /etc shortcut is not mentionned in the official docs. The only
> > > information I could find is at
> > > https://extending-lilypond.readthedocs.io/en/latest/music.html#the-etc-shortcut
> >
> >
> >
> > I'm glad that this resource is showing usefulness. On the other
> > hand, \etc *is* mentioned in the official docs. Look in the function
> > index:
> >
> > https://lilypond.org/doc/v2.23/Documentation/notation/lilypond-command-index
> >
> >
> >
> > You will find two pages (briefly) explaining its use, one in music
> > functions and one in markup commands. (The one for markup commands was
> > added in the 2.23 documentation.)
> >
> >
> >
> > > I tried to create an mve for myself but failed:
> > >
> > > boxedMark = \mark \markup { \box \etc }
> > >
> > > {
> > >
> > >   c1 d \boxedMark "Part II" e f
> > >
> > > }
> > >
> > > My current (but appearently failing) mental model is that /etc is a
> > > kind
> > > of function parameter - here called with value "Part II". (I know how
> > > procedural and oo languages work.) boxedMark is my function, and with
> > > the \etc parameter I am able to pass my value o the functions body.
> >
> >
> >
> > Well, \etc is not as general as this. For one thing, it works
> > as a trailing argument. You can have
> >
> > shortcut = \function a b \etc
> >
> > but not
> >
> > shortcut = \function \etc a b
> >
> > Basically, you should think of \etc as "cutting short" the application
> > of the function and leaving the remaining arguments to be given
> > "another time". (Hence its name.)
> >
> > Also, even if you spell it as \mark \markup \box \etc (without braces),
> > it still does not work, because \etc cannot mix music and markup
> > contexts.
> > \mark is a music function. It won't like receiving a partial markup
> > command.
> >
> > Thus, in this case, you should revert to a plain old music function
> > instead:
> >
> > boxedMark =
> > #(define-music-function (arg) (markup?)
> >    #{ \mark \markup \box #arg #})
> >
> >
> > Note how, by using #{ #} syntax, you can write such functions
> > without any knowledge of Scheme apart from the names of the
> > type predicates. The manual calls this "substitution functions",
> > explained at
> >
> > https://lilypond.org/doc/v2.23/Documentation/notation/substitution-function-syntax
> >
> >
> >
> > Type predicates are listed at
> > https://lilypond.org/doc/v2.23/Documentation/notation/predefined-type-predicates
> >
> >
> >
> > Best regards,
> > Jean