Re: More Guile 1.8 code failing in 2.x

[Ludovic Courtès]

Richard Shann <address@hidden> skribis:

> (if (defined? 'define-once)
>       (define-once ToggleTripleting::InsideTriplet #t)
>       (eval-string "(if (not (defined? 'ToggleTripleting::InsideTriplet))
>                       (define ToggleTripleting::InsideTriplet #t))"))

Rather something along these lines:

  (cond-expand ((not guile-2)
                (define-macro (define-once var expr)
                  `(if (not (defined? ',var))
                       (define ,var ,expr))))
               (guile-2 #t))

This will do nothing on Guile 2.0, and will define ‘define-once’ on 1.8.

HTH,
Ludo’.