Nope, that was it. I had thought progv would treat the binding with no argument like a free binding. Instead, it explicitly unbinds the variable.
Thanks!
Greg
On Dec 27, 2010, at 8:43 AM, Peter Seibel wrote:
I'm assuming you're surprised by the results of the forms you give below. The issue isn't that progv makes "a differest special"--it makes a new binding. So in the first form you've created a new binding for x with no supplied value so boundp returning NIL seems about right. And in the second case, you create a binding, assign it a value, and then leave the scope of the binding. Or I'm missing something about your question.
-Peter
On Sun, Dec 26, 2010 at 4:04 PM, Greg Gilley ggilley@gerg.org wrote:
There are some tests in the common-lisp test suite with dynamic binding that I don't understand. If someone could help shed some light on them I'd appreciate it.
progv makes it's arguments special. I don't understand how they can be a different special than the one declared in the let. I'd love an explanation.
(let ((x 0)) (declare (special x)) (progv '(x) () (boundp 'x))) ==> NIL
(let ((x 0)) (declare (special x)) (progv '(x) () (setq x 1)) x) ==> 0
Thanks,
Greg
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