Since we're talking about implementing it in usercode, as opposed to adding it to the language, we fortunately have the option to rework it (or have a couple co

Since we're talking about implementing it in usercode, as opposed to adding it to the language, we fortunately have the option to rework it (or have a couple completing implementations to see what works in practice). If you're looking for those particular features, I'd recommend adopting go's `, ok` idiom that appears in several places in the language. A type like: type Iterator[T any] interface { Next() (T, bool) } Lets you write code like this, if that's more to your liking: for current, ok := i.Next(); ok; current, ok = i.Next() { // do things here } Which, really seems like a more go-like way to do this in the language as well (ranging over a function then becomes syntactic sugar for the above).