GNU bug report logs - #73853
Should and-let* become a synonym for when-let*?

Previous Next

Full log

Message #11 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Michael Heerdegen <michael_heerdegen <at> web.de>
To: Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of
 text editors" <bug-gnu-emacs <at> gnu.org>
Cc: 73853 <at> debbugs.gnu.org, Stefan Monnier <monnier <at> iro.umontreal.ca>
Subject: Re: bug#73853: 31.0.50; and-let* is useless
Date: Fri, 18 Oct 2024 04:11:23 +0200

Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of
text editors" <bug-gnu-emacs <at> gnu.org> writes:

> Can we kill/deprecate this?

`and-let*'s purpose is to express conditions, `when-let*'s is
conditional evaluation.  We have `and-let*' and `when-let*' for the same
reason we have `and' and `when'.  See prior discussions.

> [ I think we have too many (if|when|and)-let(*) for our own good: we
>   should pick some winners and deprecate the other ones.   ]

AFAIR the non-star versions exist for backward compatibility only - so I
would rather get rid of these.  Parallel existence of these non-star
vs. star versions should be a temporary state, it complicates the matter
for an epsilon gain.

> I could see a use for something called `and-let(*)` but without a BODY,
> for the purpose of remove a level of parens and indentation:
>
>     (and-let*
>       (x1 (foo1))
>       (x2 (foo2)))
>
> i.s.o
>
>     (and-let*
>         ((x1 (foo1))
>          (x2 (foo2))))

Ugh! - I could not imagine anything with more potential for confusion as
removing the paren around a list of bindings.  This would add one more
year-lasting round of discussing these constructs.  If you do this,
please call it `and-let*?@!' so than everybody is warned.


Michael.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.