The last time we talked about this, we were looking at changes just to the for special form. I was in favor of that at the time. This local accumulator approach has broader language implications, and I am less comfortable with how it might affect ease of learning and evolved style.
I wonder if we could go in some other direction such as better using the into option and a custom Collectable. Or, now that I think about it, what if into could also accept an anonymous or named function instead of needing a defimpl module? I need to spend more time thinking about this since it’s a fresh idea.
