Jean Abou Samra <j...@abou-samra.fr> writes: > 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.
I don't think Duration makes a good candidate for arithmetic (you could implement 2*3/2 as (* (ly:make-duration 1) 3/2) instead of (ly:make-duration 1 0 3/2) but it seems somewhat contrived. Pitch would make more sense (there are pitch differences). -- David Kastrup
