From: JohnFredCee
Subject: Ignoring dummy symbols
Date: 
Message-ID: <1161693871.749692.146340@e3g2000cwe.googlegroups.com>
I need to silently discard the first two values returned from
decode-universal-time, in this macro, and not get a warning about
ignoring values, etc. I know you usually use (declare (ignore ..)) but
it seems a bit of a waste to create a gensym in order to ignore it.
Does anyone have any other suggestions?


(defmacro with-day-month-year  (day month year date &rest body)
  `(multiple-value-bind (,(gensym) ,(gensym) ,day ,month ,year)
       (decode-universal-time ,date) ,@body))


?
From: Pascal Bourguignon
Subject: Re: Ignoring dummy symbols
Date: 
Message-ID: <87ejsxri4o.fsf@thalassa.informatimago.com>
"JohnFredCee" <·····@yagc.ndo.co.uk> writes:

> I need to silently discard the first two values returned from
> decode-universal-time, in this macro, and not get a warning about
> ignoring values, etc. I know you usually use (declare (ignore ..)) but
> it seems a bit of a waste to create a gensym in order to ignore it.
> Does anyone have any other suggestions?

Read CLHS decode-universal-time

> (defmacro with-day-month-year  (day month year date &rest body)
>   `(multiple-value-bind (,(gensym) ,(gensym) ,day ,month ,year)
>        (decode-universal-time ,date) ,@body))

This won't help.  You need to declare them ignored.

(defmacro with-day-month-year  ((day month year date) &body body)
   (let ((h (gensym))(m (gensym))(s (gensym)))
     `(multiple-value-bind (,s ,m ,h ,day ,month ,year)
                                     (decode-universal-time ,date) 
       (declare (ignore ,s ,m ,h))
       ,@body)))


(with-day-month-year (d m y (get-universal-time))
    (list y m d))
--> (2006 10 24)


-- 
__Pascal Bourguignon__                     http://www.informatimago.com/

THIS IS A 100% MATTER PRODUCT: In the unlikely event that this
merchandise should contact antimatter in any form, a catastrophic
explosion will result.
From: JohnFredCee
Subject: Re: Ignoring dummy symbols
Date: 
Message-ID: <1161695494.427057.83490@f16g2000cwb.googlegroups.com>
Pascal Bourguignon wrote:
> "JohnFredCee" <·····@yagc.ndo.co.uk> writes:
>
> > I need to silently discard the first two values returned from
> > decode-universal-time, in this macro, and not get a warning about
> > ignoring values, etc. I know you usually use (declare (ignore ..)) but
> > it seems a bit of a waste to create a gensym in order to ignore it.
> > Does anyone have any other suggestions?
>
> Read CLHS decode-universal-time
>
I was going to say "I have"..but then I noticed the typo. D'oh.

Thanks for showing me how to use (declare (ignore ..)) in this context,

though..

> THIS IS A 100% MATTER PRODUCT: In the unlikely event that this
> merchandise should contact antimatter in any form, a catastrophic
> explosion will result.
comp.lang.lisp / 2006 / oct