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Date: Mon, 23 May 88 10:12:44 EDT
We are running genera 7.2 on 3650's. I've experienced the following 2
1) Suppose I have the following:
(defun eq-test ()
(let ((a '(a b c d))
(b '(a b c d)))
(setq *a* a)
(setq *b* b)))
After running eq-test, it turns out that *a* and *b* are eq!
This, by the way, occurs with arrays, strings, etc. The only
way to avoid this is to make liberal use of copy-* in these
I presume you have compiled EQ-TEST? The compiler is allowed to share
EQUAL constants and make them EQ.
2) Suppose I have a structure named rts which is stored as a
named vector. Given an instance of this structure, rts-1,
if I then do (setq rts-2 (copy-rts rts-1)), I find that although
every slot of rts-2 is eq to the corresponding slot in rts-1,
rts-1 and rts-2 are not equal !
Of course all the elements are EQ, you copied pointers to all of them
from the old structure into the new one. And of course RTS-1 and RTS-2
are not EQ, because RTS-2 is brand new.
Moreover, given that the nominal-equipment-list slot of rts is a list
of equipment structures, I find that
(eq (rts-nominal-equipment-list rts-1)
returns t, but when I do
(push t (rts-nominal-equipment-list rts-1))
rts-1 is modified but rts-2 is not!
Of course. The slot in RTS-2 still points to the original head of the
list, but the slot in RTS-1 now points to the new head of the list (the
one with T in it).
Thanks for your help.