[adamwk]

There are lazy collections, but they’re not default.

Why the protocols are designed the way they are is until very recently all types were implicitly copyable, but most of the collection types like array and dictionary were copy on write; so the copies were cheap. I think in general, though, there are a lot of performance footguns in the design, mainly around when copies aren’t cheap. The future protocols will hopefully rectify these performance issues.

[monkeyelite]

Yeah - super weird. It’s like they saw a nice way to avoid thinking about ownership and references, and now have to reconcile with the real problem.

All of these “replace C++” projects have been quite disappointing. Where they tried to make big simplifications they often just didn’t understand the original problem and inherent complexity - or they made a good, but opinionated design choice which has been unable to survive bureaucratic demand for more features, etc.