Re: problems with user-defined command line options

[Marc Hohl]

> cc'ing to -devel, perhaps it is a bug?

Am 24.12.2011 00:41, schrieb -Eluze:
> hi
>
>     Marc Hohl wrote:
>
>     Hello list,
>
>     I have some files with songs where I want to switch the slurs on
>     and off.
>
>     After searching the docs, I came up with this:
>
>     optional-slurs.ly
>     ==================
>
>     \version "2.15.23"
>
>     #(ly:add-option 'no-slurs #f
>             "Whether to print a slur or not.")
>
>     slurSwitch = #(define-music-function (parser location) ()
>          (if (eq? #t (ly:get-option 'no-slurs))
>              #{ \override Slur #'transparent = ##t #}
>              #{#}))
>
>     test = {
>         \slurSwitch
>         c2 ( d )
>     }
>
>     \score { \test }
>
>     ==================
>
>     If I call it with
>
>       >  lilypond optional-slurs.ly
>
>     everything is fine; when I use
>
>       >  lilypind -d no-slurs optional-slurs.ly
>
>     I get a warning that option 'no-slurs is
>     undefined, and the slurs are still visible.
>
>     Searching in the archives showed
>
>     http://lists.gnu.org/archive/html/lilypond-devel/2009-11/msg00135.html
>     http://lists.gnu.org/archive/html/lilypond-devel/2008-02/msg00080.html
>
>     with no apparent solution.
>
> i am certainly not a scheme expert but from the Application Usage i 
> can see the option -d expects a variable name and a value:
>
> /-dvar=val/
Hi Eluze,

thanks for your answer!

The extending manual says, however,

http://lilypond.org/doc/v2.15/Documentation/extending/functions-without-arguments

that I can use -d var as a boolean switch, so either the manual is wrong 
or something
has changed in lilypond's externals.
> if you invoke lilypond with *-dvar=#t yourFile.ly *you can take over 
> this value e.g. as
>
> slurSwitch = #(define-music-function (parser location) ()
>      (if (eqv? #t (ly:get-option 'var))
>          #{ \override Slur #'transparent = ##t #}
>          #{ #})
>          )
> test = {
>     \slurSwitch
>     c2 ( d )
> }
> \score { \test }

Ok, this works indeed - but the error message abound the unknown 
variable var
persists even if I define the option via ly:add-option

So something seems to be wrong - is this a bug?

Thanks,

Marc