[bmm6o]

Part of the reason people are misunderstanding you is that terminology got abused a little bit upthread.

"I just always assumed that all the variables present in a closure are maintained" should really be (something like) "I just always assumed that all the variables present in a scope that produced a closure are maintained". You're right that a closure only needs to contain the variables that are closed over, and that some of those variables are scoped such that they can appear in multiple closures.

[DanWaterworth]

> You're right that a closure only needs to contain the variables that are closed over.

You would think so, but this assumption fails in the presence of eval.

[bmm6o]

Sure, but that's the only exception, right? If there's no eval call in the function that requires the closure it's easily determined what variables don't need to be included, right?