From: Christian Neukirchen <chneukirchen@...>
Date: 2006-07-27T21:24:51+09:00
Subject: Re: RLisp - Lisp naturally embedded in Ruby

"Tomasz Wegrzanowski" <tomasz.wegrzanowski@gmail.com> writes:

> On 7/25/06, Christian Neukirchen <chneukirchen@gmail.com> wrote:
>> "Tomasz Wegrzanowski" <tomasz.wegrzanowski@gmail.com> writes:
>>
>> > On 7/25/06, Christian Neukirchen <chneukirchen@gmail.com> wrote:
>> >> Personally, I'd prefer setf.
>> >
>> > Is setf used like that in any Lisp ?
>>
>> Does Common Lisp count? :)
>
> Yeah, but setf changes variables in outside scope.
> (setf a 2)
> (defun foo ()
>  (setf a 3)
>  a
> )
> (foo) ; -> 3
> a ; -> 3

No, that's just because a is global here.  Shadow it by a local variable:

(defun foo ()
  (let (a)
  (setf a 3)
  a))

a     ; => 2
(foo) ; => 3
a     ; => 2

> I think it would be a huge win if variables were local to
> the nearest lambda (or equivalent) by default, just like in Ruby.

That's why one uses LET for local variables.  ;-)

-- 
Christian Neukirchen  <chneukirchen@gmail.com>  http://chneukirchen.org