Go 1.22

Post by simiones » Wed, Feb 07, 2024, 1:15 PM UTC

doctor_eval wrote: post #58

I’m super excited to see range over functions - iterators. It’s one of the only things I miss from Java. It took me a few reads to understand how the work, but in typical Go style (once I got it) it was so much simpler than the equivalent in most other languages I’ve used. Looking forward to it being promoted out of experimental.

  func Backward[E any](s []E) func(func(int, E) bool) {
    return func(yield func(int, E) bool) {
        for i := len(s)-1; i >= 0; i-- {
            if !yield(i, s[i]) {
                return
            }
        }
    }
  }

  IEnumerable Backward(T[] s) {
    for i := s.length-1; i >= 0; i-- {
            yield return s[i];
    }
  }

Post by simiones » Wed, Feb 07, 2024, 1:36 PM UTC

KingOfCoders wrote: post #117

simiones wrote: post #115

Earlier quoted context omitted.

range-over-functions is the experimental new feature where a function can generate a sequence by executing a bit at a time, i.e. s := []string{"hello", "world"} for i, x := range slices.Backward(s) { fmt.Println(i, x) } func Backward[E any](s []E) func(func(int, E) bool) { return func(yield func(int, E) bool) { for i := len(s)-1; i >= 0; i-- { if !yield(i, s[i]) { return } } } } I don't think anyone expects this to w…

Yes might depend on where you come from. As someone with decades of Java experience - not a fancy language over most of its lifecycle - I was mystified why there is no Iterator support as in Java for loops.

Post by doctor_eval » Wed, Feb 07, 2024, 1:47 PM UTC

simiones wrote: post #121

doctor_eval wrote: post #58

I’m super excited to see range over functions - iterators. It’s one of the only things I miss from Java. It took me a few reads to understand how the work, but in typical Go style (once I got it) it was so much simpler than the equivalent in most other languages I’ve used. Looking forward to it being promoted out of experimental.

You find func Backward[E any](s []E) func(func(int, E) bool) { return func(yield func(int, E) bool) { for i := len(s)-1; i >= 0; i-- { if !yield(i, s[i]) { return } } } } simpler than C#'s IEnumerable Backward(T[] s) { for i := s.length-1; i >= 0; i-- { yield return s[i]; } } I think that's quite hard to defend, honestly. Granted, Java doesn't have anything comparable, so I'm not sure what you're comparing this featu…

Post by shirogane86x » Wed, Feb 07, 2024, 2:00 PM UTC

puika wrote: post #85

hambos22 wrote: post #64

Earlier quoted context omitted.

> can't wait for some map/filter/find slice functions though Till that day comes, you could use the "lo" library (inspired from lodash). It's my goto Swiss army knife for golang projects. https://github.com/samber/lo

On the other hand, I advise you NOT to use this kind of library and write simple, fast go code most of the time, with the occasional generics helper. Why the hell would I clutter my code with, for example: https://github.com/samber/lo?tab=readme-ov-file#fromentries-...

Post by jjice » Wed, Feb 07, 2024, 2:15 PM UTC

lenkite wrote: post #128

mjw_byrne wrote: post #119

Perhaps I'm a dinosaur but I don't like the range-over-function addition. I don't think it adds enough convenience to justify the complexity it adds to the language, and the functional style feels at odds with Go's explicit, imperative (albeit verbose) and feature-lean style, which I think was one of its major strengths. For the same reason I think the range-over-integer feature is a misstep. Go's lean feature set an…

I also think this feature feels premature. Ideally, it should be introduced after lambdas and generic parameter packs. The Generics support in Golang is not sophisticated enough to support this at the moment leading to the strangely imposed limitations