Am Fr., 29. März 2019 um 10:00 Uhr schrieb Richard Shann <rich...@rshann.plus.com>: > > On Thu, 2019-03-28 at 18:22 -0700, Aaron Hill wrote: > > On 2019-03-28 3:14 pm, Thomas Morley wrote: > > > 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 > > This sounds like a problem I had when Denemo started running under > Guile 2 - I asked on the guile mailing list and got fixed up with > this: > > ;;; for guile 2.0 compatibility define the define-once procedure to > work in guile 1.8 > (cond-expand > (guile-2) ; nothing > (else ; guile < 2.0 > (define-macro (define-once sym exp) > `(define ,sym > (if (module-locally-bound? (current-module) ',sym) > ,sym > ,exp))))) > > Apologies in advance if this is un-related, I've not been following > this thread :( > > Richard
Hi Richard, I tried to understand what you've got from the guile-list. Thus I opened a guilev2 prompt and simply typed cond-expand: scheme@(guile-user)> (version) $1 = "2.2.4.9-71f536" scheme@(guile-user)> cond-expand While compiling expression: Syntax error: unknown location: source expression failed to match any pattern in form cond-expand scheme@(guile-user)> Well, ok, the guile-manual says: 7.5.2 SRFI-0 - cond-expand [...] So I tried: scheme@(guile-user)> (use-modules (srfi srfi-0)) While compiling expression: no code for module (srfi srfi-0) What am I missing? Cheers, Harm _______________________________________________ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user