GNU bug report logs - #18175
files.el: use mapc in (mapcar 'switch-to-buffer ...)

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Message #31 received at 18175 <at> debbugs.gnu.org (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: Ivan Shmakov <ivan <at> siamics.net>
Cc: 18175 <at> debbugs.gnu.org
Subject: Re: bug#18175: files.el: use mapc in (mapcar 'switch-to-buffer ...)
Date: Thu, 07 Aug 2014 15:29:03 -0400

> 	I tend to disagree with that last part, – it seems like a common
> 	idiom for a function (or, generally, – a /form/; setq does that,
> 	for one thing) that’s used “solely” for its side-effects to
> 	return its “primary” argument, thus allowing for easy

Yes, it's common, but I strongly dislike it.

It's used often enough for `setq' that I consider it to be an exception.

In the case of `mapc' OTOH, I'm pretty sure 99.9% of Elisp coders have no
idea what is the return value of `mapc', so using this return value is
a kind of obfuscation.

> 	Yes.  However, I believe that the last two hunks of the one
> 	another variant of the diff (MIMEd) actually make the intent to
> 	return the reverse of the list returned by find-file-noselect
> 	/clearer,/ – although at the expense of adding one extra LoC in
> 	each case.

Agreed, and neither relies on the return value of `mapc', so those two
hunks are indeed good.  Please install them.


        Stefan

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