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Re: Lexical equivalent of progv
> Date: Fri, 5 Mar 1993 14:56:19 -0800
> From: bha <@ada3.ca.boeing.com:email@example.com>
> Is there an equivalent of progv for lexical variables?
> That is, I want a form that accepts a list of variable names, and
> a list of values and binds those values to *lexical* variables over
> the body of the form. Progv does this but binds values to *dynamic*
In short, no.
If first-class environments had made it into the language, then you
could build (or augment) an environment and then evaluate the body in
this environment. (First-class environments are discussed on pages
207-214 of CLtL2, but they've since been removed from the language.)
Still, you're stuck evaluating the body -- it won't run compiled. To
compile it you'd need to be able to declare that a variable will be
lexically bound (which you can't), so that the compiler does not
either break or warn and use a dynamic reference.
Not to mention that non-lexical bindings of lexical variables is