Hi,
I'm just beginning my journey with lisp, and I wonder
what is the difference between
(setq a-variable '(something and stuff))
and
(setf a-variable '(something and stuff))
I mean exactly in statements as above, I know that setq can assing a value
to a _single_ variable and setf changes the value of given place in the
memory. But in some pieces of code I see, that people use setf JUST to
assign a value to a variable.
Is there any pros of using setf in clauses like above?
cheers,
-J
Jedrzej Nasiadek <···@yenisko.home.astercity.net> writes:
> I'm just beginning my journey with lisp, and I wonder
> what is the difference between
> (setq a-variable '(something and stuff))
> and
> (setf a-variable '(something and stuff))
No difference. SETF expands to SETQ if the variable is a normal variable.
SETQ expands to SETF if the "variable" is a symbol-macro.
The argument to SETQ can only be a symbol.
The argument to SETF can be any "place" form. Symbols are a kind of
place form.
Some people use only SETF, and this works.
Some of us, out of tradition, mostly, use SETQ for variables and SETF for
non-variables [i.e., for more complicated "places"].
> I mean exactly in statements as above, I know that setq can assing a value
> to a _single_ variable and setf changes the value of given place in the
> memory. But in some pieces of code I see, that people use setf JUST to
> assign a value to a variable.
> Is there any pros of using setf in clauses like above?
The issue is purely personal taste in the example you offer.
On 11 May 2001 01:34:17 +0100, Jedrzej Nasiadek
<···@yenisko.home.astercity.net> wrote:
> I mean exactly in statements as above, I know that setq can assing a value
> to a _single_ variable and setf changes the value of given place in the
You can actually use SETQ with more than one variable:
(setq var1 val1
var2 val2
;; ...
var-n val2)
Paolo
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