From: Maxim Cournoyer <maxim.cournoyer@gmail.com>
To: zimoun <zimon.toutoune@gmail.com>
Cc: "Ludovic Courtès" <ludo@gnu.org>,
59164@debbugs.gnu.org, 58812@debbugs.gnu.org
Subject: [bug#58812] [bug#59164] Coding style: similarly-named variables
Date: Fri, 18 Nov 2022 12:02:44 -0500 [thread overview]
Message-ID: <87y1s82o23.fsf@gmail.com> (raw)
In-Reply-To: <86zgcpju9p.fsf@gmail.com> (zimoun's message of "Thu, 17 Nov 2022 19:44:18 +0100")
Hi,
zimoun <zimon.toutoune@gmail.com> writes:
> Hi,
>
> On Thu, 17 Nov 2022 at 18:37, Ludovic Courtès <ludo@gnu.org> wrote:
>
>>> It's a pattern I've used at other places; I find it more hygienic to not
>>> shadow existing variables; it signal to the reader "be careful, this is
>>> not the same as the argument-bound one, though they are closely
>>> related".
>>
>> I don’t buy it. :-) The reader might be careful yet end up using the
>> “wrong” variable. As long as the “wrong” variable has no use, I think
>> it’s best to shadow it so that mistakes cannot happen.
>>
>> Of course the details vary depending on context, but I think we should
>> not start introducing this pattern in different places. Perhaps
>> something to discuss and codify under “Formatting Code”?
>
> I agree with Ludo. For another instance than target*, the previous was,
>
> ((new '-> old)
> [...]
> - (symlink old (string-append target new)))
> [...]
> - (delete-file (string-append target new))
>
>
> then replaced by,
>
> ((new '-> old)
> [...]
> + (let ((new* (string-append target* new)))
> [...]
> + (error (format #f "symlink `~a' points to nonexistent \
> +file `~a'" new* old)))))
> + (symlink old new*))
The intent was to keep away from the following imperative style, which
hurts both readability and debuggability in my opinion:
--8<---------------cut here---------------start------------->8---
(let* ((my-target "something")
(my-target (mutate-once my-target))
(my-target (mutate-twice my-target)))
(do-something-with my-target))
--8<---------------cut here---------------end--------------->8---
Perhaps the problem at hand would benefit being broken down in smaller
chunks, to avoid having a page-full of code sharing the same scope.
--
Thanks,
Maxim
next prev parent reply other threads:[~2022-11-18 17:03 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-27 3:41 [bug#58812] [PATCH 0/5] Add --symlink option to 'guix shell' Maxim Cournoyer
2022-10-27 3:50 ` [bug#58812] [PATCH 1/5] Makefile.am: Sort EXTRA_DIST entries Maxim Cournoyer
2022-10-27 3:50 ` [bug#58812] [PATCH 2/5] tests: Add a tests/utils.sh support file Maxim Cournoyer
2022-11-09 21:07 ` [bug#58812] [PATCH 0/5] Add --symlink option to 'guix shell' Ludovic Courtès
2022-11-10 3:38 ` Maxim Cournoyer
2022-11-10 4:23 ` [bug#59164] [PATCH v2 1/4] Makefile.am: Sort EXTRA_DIST entries Maxim Cournoyer
2022-11-10 4:23 ` [bug#59161] [PATCH v2 2/4] install: Validate symlink target in evaluate-populate-directive Maxim Cournoyer
2022-11-10 4:23 ` [bug#59162] [PATCH v2 3/4] guix: shell: Add '--symlink' option Maxim Cournoyer
2022-11-10 4:23 ` [bug#59163] [PATCH v2 4/4] shell: Detect --symlink spec problems early Maxim Cournoyer
2022-10-27 3:50 ` [bug#58812] [PATCH 3/5] install: Validate symlink target in evaluate-populate-directive Maxim Cournoyer
2022-11-09 21:06 ` [bug#58812] [PATCH 0/5] Add --symlink option to 'guix shell' Ludovic Courtès
2022-11-10 3:37 ` Maxim Cournoyer
2022-11-17 17:37 ` [bug#59164] Coding style: similarly-named variables Ludovic Courtès
2022-11-17 18:44 ` [bug#58812] " zimoun
2022-11-18 17:02 ` Maxim Cournoyer [this message]
2022-11-21 15:02 ` zimoun
2022-11-21 15:52 ` [bug#59164] " zimoun
2022-11-21 20:55 ` Maxim Cournoyer
2022-11-22 14:35 ` [bug#59164] " zimoun
2022-11-25 15:23 ` Guile debugger workgroup? (was: Coding style: similarly-named variables) Maxim Cournoyer
2022-11-26 11:22 ` Guile debugger workgroup? Ludovic Courtès
2022-11-27 3:16 ` Maxim Cournoyer
2022-11-28 10:53 ` Ludovic Courtès
2022-11-28 13:41 ` Attila Lendvai
2022-11-28 14:50 ` Maxim Cournoyer
2022-11-29 8:46 ` Ludovic Courtès
2022-11-30 3:44 ` Attila Lendvai
2022-11-27 12:04 ` zimoun
2022-11-28 0:27 ` Maxim Cournoyer
2022-11-28 11:06 ` Ludovic Courtès
2022-11-28 12:31 ` zimoun
2022-11-27 20:46 ` Attila Lendvai
2022-11-28 0:41 ` David Pirotte
2022-11-28 0:45 ` David Pirotte
2022-11-28 2:06 ` Maxim Cournoyer
2022-11-28 7:22 ` Joshua Branson
2022-11-28 11:09 ` Ludovic Courtès
2022-11-28 14:12 ` Attila Lendvai
2022-11-29 8:54 ` Ludovic Courtès
2022-11-28 12:24 ` Guile debugger workgroup? (was: Coding style: similarly-named variables) Csepp
2022-11-30 7:09 ` Guile debugger workgroup? Jannneke Nieuwenhuizen
2022-11-26 14:47 ` [bug#58812] [bug#59164] Coding style: similarly-named variables Ludovic Courtès
2022-11-17 20:34 ` Maxim Cournoyer
2022-11-20 10:46 ` [bug#58812] " Ludovic Courtès
2022-10-27 3:50 ` [bug#58812] [PATCH 4/5] guix: shell: Add '--symlink' option Maxim Cournoyer
2022-11-09 20:58 ` [bug#58812] [PATCH 0/5] Add --symlink option to 'guix shell' Ludovic Courtès
2022-11-10 3:10 ` Maxim Cournoyer
2022-11-10 14:17 ` Ludovic Courtès
2022-11-10 14:49 ` Maxim Cournoyer
2022-11-10 15:16 ` Maxim Cournoyer
2022-11-14 9:18 ` Ludovic Courtès
2022-11-10 16:05 ` [bug#58812] [PATCH v3 1/4] Makefile.am: Sort EXTRA_DIST entries Maxim Cournoyer
2022-11-10 16:05 ` [bug#58812] [PATCH v3 2/4] install: Validate symlink target in evaluate-populate-directive Maxim Cournoyer
2022-11-10 16:05 ` [bug#58812] [PATCH v3 3/4] guix: shell: Add '--symlink' option Maxim Cournoyer
2022-11-10 16:05 ` [bug#58812] [PATCH v3 4/4] shell: Detect --symlink spec problems early Maxim Cournoyer
2022-11-16 19:03 ` [bug#58812] [PATCH 0/5] Add --symlink option to 'guix shell' zimoun
2022-11-16 19:34 ` Maxim Cournoyer
2022-10-27 3:51 ` [bug#58812] [PATCH 5/5] shell: Detect --symlink spec problems early Maxim Cournoyer
2022-11-15 21:24 ` bug#58812: [PATCH v3 1/4] " Maxim Cournoyer
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