Very cool. While struggling with the $vau concept I thought about whether I could build lazy eval directly using $vau, without first building force and delay (SICP 4.2). But it's not quite that powerful, because lazy eval also needs the ability to stop computing the cdr of a value. Your intuition tying $vau to continuations is a similar you-see-it-if-you-squint-a-little correspondence.
I somewhat remember either the Kernel Report or John's dissertation mentioning the similarities between continuations and environments, but I might be mistaken on that...
---
"I thought about whether I could build lazy eval directly using $vau"
Directly? Not sure, but ยง9.1.3 of the Kernel Report does show how to build promise?, memoize, $lazy, and force as a library using existing Kernel features.
