On Tue, Jun 16, 2020 at 1:54 PM Arnaud Delobelle <arnaud.delobe...@sparx.co.uk> wrote: > > I noticed today the blog post about the revised Generics proposal. What got > me excited is this extract at the start: > > The biggest change is that we are dropping the idea of contracts. The > difference between contracts and interface types was confusing, so we’re > eliminating that difference. > > To me the lack of orthogonality between contracts and interfaces was the > major issue with the previous proposal and I have been musing with ways of > resolving it for a while, so I am very pleased that the proposal is going > down this path! > > Last month I decided to write a post about a way of introducing Generics into > Go using interfaces, which I called "Package Specialization". > > Headline features are: > > use interfaces to express parametric types; > no new keyword; > the only new syntax is “package specialization”: pkg(T=int, Y=*MyType).Func(); > generic code which doesn’t use the package specialization syntax is already > valid Go. > > The full post can be read here: > https://arnodel.github.io/marooned/go/generics/2020/06/06/go-spec2.html > > I was toying with the idea of submitting it here for feedback, to try to move > the discussion in that direction. Well, I guess today's updated proposal > steals my thunder! Essentially this is the same idea, but with a different > manifestation in the language - I thought that submitting it anyway may > provide a useful comparison point to help gauge the updated proposal better. > > Note that sadly, I do not have much time to polish a proposal or to follow > discussions in general on this or other golang-related discussion lists, so I > apologize in advance if I am inadvertently re-hashing ideas that have been > put forward and dismissed in the past, or if my blog post is a little low on > detail (it was meant to be an exploration of a possible approach).
Thanks. I hadn't seen that before. A difficulty with package specialization is when you want to write a List(List(int)). That is, a List where each element of the List is a List(int). Or, when you want to write a transformation function as in https://go.googlesource.com/proposal/+/refs/heads/master/design/go2draft-type-parameters.md#list-transform. It would seem to require some modification of how imports work in Go, and that leads into considerable complexity. See also .https://go.googlesource.com/proposal/+/refs/heads/master/design/go2draft-type-parameters.md#why-not-put-type-parameters-on-packages . Ian -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAOyqgcVS%3Dae90U51y_%2BN6a00Ve6UTK%3DNfqz38LhzuMSBDrXmZQ%40mail.gmail.com.
