From: Stefan Monnier <monnier@iro.umontreal.ca>
To: Pip Cet <pipcet@protonmail.com>
Cc: Stefan Kangas <stefankangas@gmail.com>,
Tassilo Horn <tsdh@gnu.org>, Eli Zaretskii <eliz@gnu.org>,
Anand Tamariya <atamariya@gmail.com>,
emacs-devel@gnu.org
Subject: Re: Negative nth index
Date: Wed, 25 Dec 2024 12:22:00 -0500 [thread overview]
Message-ID: <jwvpllfel2o.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <87r05wahsi.fsf@protonmail.com> (Pip Cet's message of "Tue, 24 Dec 2024 21:33:17 +0000")
>> [ I'd make it return 2 otherwise you can't use it to return the
>> last element. ]
> I think the OP meant that (nth -1 '(1 2)) is 1 on current Emacs, which
> is definitely unexpected.
Ah.. you're right that makes a lot more sense.
>> I don't see a strong argument in favor of making it index from the end
>> rather than signal an error. What would the implementation look like?
> I agree, but the current implementation does not signal an error. It
> should, and I think that's what the suggestion was.
Sorry for misreading. I'd prefer that we signal an error, yes.
Not sure it's worth the risk of breaking existing code, OTOH.
Stefan
next prev parent reply other threads:[~2024-12-25 17:22 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-22 5:43 Negative nth index Anand Tamariya
2024-12-22 7:39 ` Eli Zaretskii
2024-12-22 9:01 ` Tassilo Horn
2024-12-23 5:40 ` Stefan Kangas
2024-12-24 5:11 ` Stefan Monnier
2024-12-24 6:42 ` Teemu Likonen
2024-12-24 6:48 ` Thierry Volpiatto
2024-12-24 13:09 ` Philip Kaludercic
2024-12-24 15:18 ` Stefan Monnier
2024-12-24 15:24 ` Sebastián Monía
2024-12-24 21:33 ` Pip Cet via Emacs development discussions.
2024-12-25 10:30 ` Mattias Engdegård
2024-12-25 10:56 ` Pip Cet via Emacs development discussions.
2024-12-25 12:14 ` Mattias Engdegård
2024-12-25 13:04 ` Pip Cet via Emacs development discussions.
2024-12-25 14:23 ` Stefan Kangas
2024-12-25 17:22 ` Stefan Monnier [this message]
2024-12-25 14:18 ` Stefan Kangas
2024-12-22 10:16 ` Andreas Schwab
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