Re: Snippet variations

[Simon Albrecht]

On 18.12.2016 23:30, Br. Samuel Springuel wrote:
> Some Googling led me to this idea:
> #(if (not (defined? aster)) (aster = { \set stanza = \markup{"*"} }))
>
> but this mixes scheme and lilypond syntax in a way I suspect is not 
> allowed

Yes :-)
Here’s how:
#(if (not (defined? 'aster))
    (define aster #{ \set stanza = \markup "*" #}))

– IIRC, defined? takes a symbol, so you have to quote ‘aster’ using '
– Use a scheme define while in scheme
– when in Scheme, use #{#} to have something evaluated by the LilyPond 
parser again (instead of the Guile interpreter)

HTH, Simon