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From: Ihor Radchenko <yantar92@posteo.net>
To: "Mattias Engdegård" <mattias.engdegard@gmail.com>
Cc: Juanma Barranquero <lekktu@gmail.com>,
	emacs-devel <emacs-devel@gnu.org>,
	"Dr. Arne Babenhauserheide" <arne_bab@web.de>
Subject: Re: Warn about comparing quoted lists (etc) using `eq`
Date: Thu, 15 Dec 2022 10:50:37 +0000	[thread overview]
Message-ID: <874jtxueiq.fsf@localhost> (raw)
In-Reply-To: <58A7E984-95CC-4F7F-817B-10E680E5966E@gmail.com>

Mattias Engdegård <mattias.engdegard@gmail.com> writes:

> While this sounds like a useful suggestion on the surface, it's actually slightly dangerous: blindly replacing `eq` with `equal` (and `memq` with `member`, and so on) may very well break working code (that silently relied on the condition not being true). It's also a poor remedy against pratfalls like
>
>   (memq x '(one 'two 'three))
>
> which do occur. What we really want is to make a human look at the code, and think.

Then, there should also be a way to tell the compiler not to throw the
warning in specific, checked, places in the code.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>



  parent reply	other threads:[~2022-12-15 10:50 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-14 18:17 Warn about comparing quoted lists (etc) using `eq` Mattias Engdegård
2022-12-14 18:29 ` Eli Zaretskii
2022-12-14 20:57   ` Mattias Engdegård
2022-12-14 18:57 ` [External] : " Drew Adams
2022-12-15  4:17 ` Juanma Barranquero
2022-12-15  6:34   ` Dr. Arne Babenhauserheide
2022-12-15  7:00     ` Juanma Barranquero
2022-12-15  9:36   ` Mattias Engdegård
2022-12-15 10:06     ` Juanma Barranquero
2022-12-15 10:50     ` Ihor Radchenko [this message]
2022-12-15 13:58       ` Mattias Engdegård
2022-12-15 16:13     ` [External] : " Drew Adams

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