From: Stephen Berman <stephen.berman@gmx.net>
To: Eli Zaretskii <eliz@gnu.org>
Cc: schwab@suse.de, p.stephani2@gmail.com, mail@nicolasgoaziou.fr,
emacs-devel@gnu.org
Subject: Re: member inconsistency?
Date: Thu, 28 Jan 2016 18:30:04 +0100 [thread overview]
Message-ID: <87wpqt8vdv.fsf@gmx.net> (raw)
In-Reply-To: <83bn85zovm.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 28 Jan 2016 17:48:29 +0200")
On Thu, 28 Jan 2016 17:48:29 +0200 Eli Zaretskii <eliz@gnu.org> wrote:
>> From: Stephen Berman <stephen.berman@gmx.net>
>> Date: Thu, 28 Jan 2016 11:25:33 +0100
>> Cc: Philipp Stephani <p.stephani2@gmail.com>,
>> Nicolas Goaziou <mail@nicolasgoaziou.fr>, emacs-devel@gnu.org
>>
>> In contrast, `member' (and `memql' in the float case) has no check
>> and also uses a for-loop with the condition CONSP (tail), and when
>> this fails, the function just returns Qnil. Adding CHECK_LIST
>> (list) before the for-loop makes (member 'a 'b) signal an error.
>
> I'd say CHECK_LIST_CONS, not CHECK_LIST, don't you agree?
To be honest, I overlooked that CHECK_LIST_CONS is inside the for-loop.
But it seems a bit ugly to have the same check before the loop and
inside it as well. How about the following:
diff --git a/src/fns.c b/src/fns.c
index 86ad333..17c4a75 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -1349,7 +1349,7 @@ The value is actually the tail of LIST whose car is ELT. */)
(register Lisp_Object elt, Lisp_Object list)
{
register Lisp_Object tail;
- for (tail = list; CONSP (tail); tail = XCDR (tail))
+ for (tail = list; CONSP (tail) || !NILP (tail); tail = XCDR (tail))
{
register Lisp_Object tem;
CHECK_LIST_CONS (tail, list);
Or is having the check before the loop better it catches the error sooner?
Steve Berman
next prev parent reply other threads:[~2016-01-28 17:30 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-28 8:42 member inconsistency? Nicolas Goaziou
2016-01-28 9:41 ` Philipp Stephani
2016-01-28 10:14 ` Andreas Schwab
2016-01-28 10:25 ` Stephen Berman
2016-01-28 15:48 ` Eli Zaretskii
2016-01-28 17:30 ` Stephen Berman [this message]
2016-01-28 18:35 ` Eli Zaretskii
2016-01-28 21:57 ` Stephen Berman
2016-01-28 22:18 ` Andreas Schwab
2016-01-28 22:41 ` Stephen Berman
2016-01-28 23:38 ` Johan Bockgård
2016-01-28 23:57 ` Stephen Berman
2016-01-29 10:25 ` Andreas Schwab
2016-01-29 11:20 ` Stephen Berman
2016-01-29 14:15 ` Eli Zaretskii
2016-01-29 19:17 ` John Wiegley
2016-01-29 23:58 ` Richard Stallman
2016-02-01 7:10 ` Fabrice Popineau
2016-02-01 11:04 ` Richard Stallman
2016-02-01 12:20 ` Fabrice Popineau
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