On Thu, Oct 18, 2018 at 6:35 AM Robert Engels <reng...@ix.netcom.com> wrote: > > I meant to say contract not interface. Also as a user of said generic routine > how do I know all of the available method on a type I would need to implement > as I don’t know which ones the method may be using... > > Interfaces solve the latter as I need to implement all of them in order to be > an interface. > > On Oct 18, 2018, at 7:21 AM, Robert Engels <reng...@ix.netcom.com> wrote: > > I think the problem with the proposal is that it is going to be very hard for > the compiler to know all of the operations a type can perform since for > concrete types the methods can be spread across multiple files. With an > interface it is only declared in a single location.
I don't understand why that would be a problem. For a method declaration of the form: func f(type T like (int64,float64)(a,b)) the compiler compiles f twice: once as func f(a,b int64) and once as func f(a,b float64). In general, for a function f with multiple parameterized types containing multiple "like" types, f is compiled for all combinations of those "like" types. So the compiler doesn't need to know all the operations a type has. > > On Oct 18, 2018, at 2:20 AM, Beoran <beo...@gmail.com> wrote: > > I think the idea we should focus on here is "The type is the contract". > Instead of specifying a contract though operations, just use concrete types, > including primitive types to specify the desired qualities of the generic > type. > > Op donderdag 18 oktober 2018 08:52:30 UTC+2 schreef kortschak: >> >> If you require that a single like type applies to all the labels in the >> parameter declaration, such that func f(a, b T like int, c, d T2 like >> string) means a and be must be like T's instantiating type, and c and d >> must be like T2's unstantiating type, then you get that. >> >> If you only require a single like for any type T, something like func >> f(in T like int) (out T), then you get the type safety on return. >> >> Of course, this takes you back essentially to contracts, but with an >> alternative declaration for the type characteristics. >> >> Maybe it would be possible to use like in contracts in place of the >> example-base approach. >> >> On Wed, 2018-10-17 at 14:21 -0700, Andy Balholm wrote: >> > I think there are serious issues with your syntax for functions and >> > “templates.” For example, there doesn’t seem to be a way to specify >> > that two parameters to a function need to be the same type, or that >> > the return type will be the same as the parameter. The syntax from >> > the official proposal is superior in that regard. >> > >> > But replacing contracts with “like” definitely sounds like something >> > worth investigating. >> > >> > Andy >> > > > -- > 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. > For more options, visit https://groups.google.com/d/optout. > > -- > 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. > For more options, visit https://groups.google.com/d/optout. > > -- > 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. > For more options, visit https://groups.google.com/d/optout. -- 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. For more options, visit https://groups.google.com/d/optout.
