Re: Should we be touching goops?

[Jean Abou Samra]

Le 03/06/2022 à 02:32, David Kastrup a écrit :
> GOOPS was supposed to cause quite a performance hit with Guile 1.8 when
> used extensively.  It wasn't supposed to do this with Guile 2+ so
> something like this should be feasible, also for other types:
>
> #(use-modules (oop goops))
>
> #(define <Moment> (class-of (ly:make-moment 0)))
>                 
> #(define-method (+ (a <Moment>) (b <Moment>)) (ly:moment-add a b))
> #(define-method (- (a <Moment>) (b <Moment>)) (ly:moment-sub a b))
>
> #(display (- (ly:make-moment 3) (ly:make-moment 4) (ly:make-moment 2)))
>
> For those types where manipulation is frequent enough that we defined
> arithmetic (and possibly other) operators rather than ordinary functions
> in C++, there may be some point in doing the same in Scheme with
> generics.



Nice! I wasn't aware that GOOPS had become faster
in Guile 2, nor even that it supported smob types.
I had stayed in the conception that it was a "don't
use" module.

I'd be in favor of doing this. It will ease writing
operations on moments and such. What other types could
use it? Moment and Duration stand as obvious candidates.