Right, I completely forgot about the "stackness" of scope on the implementation side. Sides, actually, because both compile time and run time tend to be stacks.

Right, I completely forgot about the "stackness" of scope on the implementation side. Sides, actually, because both compile time and run time tend to be stacks. If course they'd still be stacks, just with an unavailable marker attached to the "undeclared". Fortunately, these days languages that are imperative at their core pick up "functional spillover" like that kotlin let seem to solve that nuisance-grade problem of a dangling `foo` temp just fine. (the kotlin let is basically a list transform applied to a single instance, without all the pointless ceremony of wrapping as an Optional. I wanted to like scala more than kotlin, but I've come to respect kotlin a lot, for striking a balance between "language designer high" and the pragmatic mundane that must never be allowed full reign or else we get another groovy)