GNU bug report logs - #75170
add-to-alist: new function

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From: Eli Zaretskii <eliz <at> gnu.org>
To: stefankangas <at> gmail.com, acorallo <at> gnu.org
Cc: 75170 <at> debbugs.gnu.org, winkler <at> gnu.org
Subject: bug#75170: add-to-alist: new function
Date: Sat, 18 Jan 2025 11:33:28 +0200

Ping!

> Cc: 75170 <at> debbugs.gnu.org
> Date: Sun, 05 Jan 2025 17:21:00 +0200
> From: Eli Zaretskii <eliz <at> gnu.org>
> 
> > From: Roland Winkler <winkler <at> gnu.org>
> > Cc: 75170 <at> debbugs.gnu.org
> > Date: Sun, 29 Dec 2024 08:50:18 -0600
> > 
> > On Sun, Dec 29 2024, Eli Zaretskii wrote:
> > > What is the advantage of adding this function, given that add-to-list
> > > can be used with alists, and given that alist-get can nowadays be used
> > > as a generalize variable?
> > 
> > The advantage I see for also having the function add-to-alist is the
> > following:
> > 
> > add-to-list checks for the presence of an element in a list.  In the
> > case of alists, this means it checks for the presence of associations.
> > You cannot easily modify an existing association with add-to-list.  If
> > you have an alist with association (foo . bar) and you call add-to-list
> > with an element (foo . baz), add-to-list will not remove the association
> > (foo . bar), but the alist will then contain both associations.
> > 
> > add-to-alist checks for the presence of keys and it makes sure that each
> > key appears only once in an alist.  By default, it replaces the value of
> > an existing key.  This makes it easy to modify an existing association.
> > Only with the optional arg NO-REPLACE non-nil, it will preserve an
> > existing association.
> > 
> > Say, I want in my .emacs file a more complicated association for a key,
> > and I do not get initially what I want.  I can call add-to-alist
> > multiple times, till I get what I want.
> > 
> > Is there a simple way to accomplish this in other ways (a way that we
> > recommend for users in their init file if they do not want to use
> > customize like me)?
> > 
> > Would it make sense to give this functions a different name if more
> > often it may be used to modify existing associations in an alist instead
> > of adding new ones?
> 
> Let's hear the other co-maintainers.
> 
> Stefan and Andrea, WDYT about this?  Should we add this function?
> 
> 
> 
> 

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