That makes no sense, the bindings in the let are independent.
On 03/08/15 22:42, Laughing Water wrote:
It looks like you need a LET* to guarantee the order of evaluation within your
LET. Otherwise, it’s undefined.
Laughing Water
On Aug 3, 2015, at 3:27 PM, Jean-Claude Beaudoin
<jean.claude.beaud...@gmail.com> wrote:
Please consider the following code:
(defparameter init-a 1)
(let ((init-a 42) (serial-no 0))
(defstruct foo (a init-a) (b (incf serial-no)))
(defun get-foo-serial-no () serial-no))
(defstruct (bar (:include foo)) (c 33) d)
When one loads the above and then try to call #'make-bar the result
varies widely from one lisp implementation (clisp) to another.
clisp: (make-bar) --> #S(BAR :A 1 :B 1 :C 33 :D NIL)
ccl: (make-bar) --> <enter the debugger saying: "Unbound variable: SERIAL-NO">
lispworks, allegro and sbcl also behave more or less like ccl.
What is the proper ANSI-CL behavior in this case here?
Is clisp right in evaluating the slot initform in its "proper" lexical context?
Or is the correct behavior to replicate the slot initform verbatim
in the sub-structure constructor regardless of its original lexical context
like the others do?
I guess that this question has probably been asked before, in a somewhat
distant past, but my google skills have not been sharp enough to find it, sorry.
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