[Chicken-users] imlib2 and define/clone

[Graham Fawcett]

Hi Peter,

The (define/clone) syntax in imlib2 isn't quite right: it never
returns a copy of the cloned object. (So, for example, (imlib:blur
my-image) returns an undefined value, instead of a blurred clone of
my-image.

(define-syntax define/clone
 (syntax-rules ()
   ((define/clone ?name ?name!)
    (define (?name img . args)
      (apply ?name! (imlib:clone img) args)))))

Maybe your destructive versions used to return a copy of the image?
I don't use syntax-rules much, but I think this is right:

(define-syntax define/clone
 (syntax-rules ()
   ((define/clone ?name ?name!)
    (define (?name img . args)
      (let ((clone (imlib:clone img)))
        (apply ?name! clone args)
        clone)))))

Cheers,
Graham