Are these identical in Common Lisp? I had thought so, however in
XLisp-Stat they are not for some functions.
For example for (spin-plot '( a b c)) does not work in XLisp-Stat whereas
(spin-plot (list a b c)) does. If I substitute '+' for 'spin-plot'
the function performs properly. Is that right? If it is, how do I
examine the two different data structures, i.e. what function do I use
to see their internal representation.
* John Somerville
| Are these identical in Common Lisp?
no. '(a b c) is identical to (quote (a b c)), which evaluates to (a b c),
a list of the three symbols a, b, and c. (list a b c) evaluates to a list
of the values of the symbols a, b, and c, and thus depends on the value of
a, b, and c, at the time of the call.
e.g.,
(let ((a 1)
(b 2)
(c 3))
(print '(a b c))
(print (list a b c))
(values))
prints
(A B C)
(1 2 3)
I didn't understand your second question.
#\Erik
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In article <··········@fountain.mindlink.net> John Somerville <···············@mindlink.bc.ca> writes:
>
> Are these identical in Common Lisp? I had thought so, however in
> XLisp-Stat they are not for some functions.
>
> For example for (spin-plot '( a b c)) does not work in XLisp-Stat whereas
> (spin-plot (list a b c)) does. If I substitute '+' for 'spin-plot'
> the function performs properly. Is that right? If it is, how do I
> examine the two different data structures, i.e. what function do I use
> to see their internal representation.
If 'spin-plot' is a function then they will both be evaluated to the same
internal structure. That's why the '+' works because '+' is a function. If
'spin-plot' is a macro then it depends on how the macro treats that argument.
That is, if 'spin-plot' is a macro it would see
(spin-plot (quote (a b c)))
versus
(spin-plot (list a b c))
which are two very different things if the macro decides to not evaluate
them and does some strange thing with the constant list argument. You can
test if 'spin-plot' is a macro by typing
(macro-function 'spin-plot)
if it returns non-NIL then 'spin-plot' is a macro and may explain the strange
behavior.
--
William P. Vrotney - ·······@netcom.com