Am Do., 28. März 2019 um 22:22 Uhr schrieb Aaron Hill <lilyp...@hillvisions.com>: > > On 2019-03-28 2:18 pm, Valentin Villenave wrote: > > On 3/28/19, Pedro Pessoa <pedrops...@gmail.com> wrote: > >> I imagined something like: > >> > >> %%% pseudo > >> #(define var > >> (not (is-bound? var) 0)) > >> %%% > > > > I’d probably probably do something like > > > > (null? (ly:parser-lookup 'var)) > > > > But I’m sure there are better ways :-) > > ;;;; > (if (not (defined? 'foo)) (define foo 47)) > ;;;; > > > -- Aaron Hill
It's worth mentioning, the above will throw an error in guilev2: error: GUILE signaled an error for the expression beginning here # (if (not (defined? 'foo)) (define foo 47)) definition in expression context, where definitions are not allowed Probably better get used to below: #(if (not (defined? 'foo)) (ly:parser-define! 'foo 47)) Cheers, Harm _______________________________________________ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
