GNU bug report logs - #71047
[PATCH] doc: Recommend alist-copy instead of list-copy.

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Message #10 received at 71047-done <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: Tomas Volf <~@wolfsden.cz>
Cc: 71047-done <at> debbugs.gnu.org
Subject: Re: bug#71047: [PATCH] doc: Recommend alist-copy instead of list-copy.
Date: Sat, 26 Oct 2024 19:33:42 +0200

Tomas Volf <~@wolfsden.cz> skribis:

> The current recommendation of `list-copy' is not right and does not lead
> to preserving the original list:
>
>     scheme@(guile-user)> (define x (list (cons 'a 1) (cons 'b 2)))
>     scheme@(guile-user)> (define y (list-copy x))
>     scheme@(guile-user)> (assq-set! y 'b 3)
>     $1 = ((a . 1) (b . 3))
>     scheme@(guile-user)> x
>     $2 = ((a . 1) (b . 3))
>
> Correct approach seems to be use `alist-copy' from SRFI-1 leading to the
> expected behavior of:
>
>     scheme@(guile-user)> ,use (srfi srfi-1)
>     scheme@(guile-user)> (define x (list (cons 'a 1) (cons 'b 2)))
>     scheme@(guile-user)> (define y (alist-copy x))
>     scheme@(guile-user)> (assq-set! y 'b 3)
>     $1 = ((a . 1) (b . 3))
>     scheme@(guile-user)> x
>     $2 = ((a . 1) (b . 2))
>
> * doc/ref/api-data.texi (Adding or Setting Alist Entries): Recommend
> `alist-copy'.

Applied, thanks!

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