GNU bug report logs - #19975
25.0.50; Add %s-like descriptor to `format' that treats nil like empty string

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Drew Adams <drew.adams <at> oracle.com>
To: bug-gnu-emacs <at> gnu.org
Subject: 25.0.50; Add %s-like descriptor to `format' that treats nil like
 empty string
Date: Sun, 1 Mar 2015 07:32:56 -0800 (PST)

Enhancement request.  Add a new format descriptor to `format' that would
behave just like %s except that a nil argument would be treated as if it
were "".

This is a convenience only, to obviate needing to pass an argument such
as `(if something "foobar" "")' or needing to combine use of `format'
with use of `concat'.

In GNU Emacs 25.0.50.1 (i686-pc-mingw32)
 of 2014-10-20 on LEG570
Bzr revision: 118168 rgm <at> gnu.org-20141020195941-icp42t8ttcnud09g
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --enable-checking=yes,glyphs CPPFLAGS=-DGLYPH_DEBUG=1'

Message #8 received at 19975 <at> debbugs.gnu.org (full text, mbox):

From: Drew Adams <drew.adams <at> oracle.com>
To: 19975 <at> debbugs.gnu.org
Subject: RE: bug#19975: 25.0.50; Add %s-like descriptor to `format' that
 treats nil like empty string
Date: Sun, 1 Mar 2015 07:37:23 -0800 (PST)

FYI, this request was inspired by this emacs.stackexchange
question: http://emacs.stackexchange.com/q/9698/105.

Message #11 received at 19975 <at> debbugs.gnu.org (full text, mbox):

From: Andreas Schwab <schwab <at> linux-m68k.org>
To: Drew Adams <drew.adams <at> oracle.com>
Cc: 19975 <at> debbugs.gnu.org
Subject: Re: bug#19975: 25.0.50;
 Add %s-like descriptor to `format' that treats nil like empty string
Date: Sun, 01 Mar 2015 17:44:46 +0100

Drew Adams <drew.adams <at> oracle.com> writes:

> Enhancement request.  Add a new format descriptor to `format' that would
> behave just like %s except that a nil argument would be treated as if it
> were "".

It's easy enough to use (or foo "").

Andreas.

-- 
Andreas Schwab, schwab <at> linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Message #14 received at 19975 <at> debbugs.gnu.org (full text, mbox):

From: Drew Adams <drew.adams <at> oracle.com>
To: Andreas Schwab <schwab <at> linux-m68k.org>
Cc: 19975 <at> debbugs.gnu.org
Subject: RE: bug#19975: 25.0.50; Add %s-like descriptor to `format' that
 treats nil like empty string
Date: Sun, 1 Mar 2015 23:07:13 -0800 (PST)

> > Enhancement request.  Add a new format descriptor to `format' that would
> > behave just like %s except that a nil argument would be treated as if it
> > were "".
> 
> It's easy enough to use (or foo "").

Yes of course "it's easy enough".  That's what we've all been
doing for decades.  It would be even clearer and simpler still
to have a format descriptor for this common use case.

That is what this enhancement request is about - not needing to
write such "easy enough" code.

And of course it is not always (or foo "").
It might well be (if foo "whatever" "").  Or if you prefer,
(let ((bar "whatever")) (or (and foo bar) "")).

Message #17 received at 19975 <at> debbugs.gnu.org (full text, mbox):

From: Andreas Schwab <schwab <at> linux-m68k.org>
To: Drew Adams <drew.adams <at> oracle.com>
Cc: 19975 <at> debbugs.gnu.org
Subject: Re: bug#19975: 25.0.50;
 Add %s-like descriptor to `format' that treats nil like empty string
Date: Mon, 02 Mar 2015 09:52:20 +0100

Drew Adams <drew.adams <at> oracle.com> writes:

> And of course it is not always (or foo "").
> It might well be (if foo "whatever" "").  Or if you prefer,
> (let ((bar "whatever")) (or (and foo bar) "")).

You can write arbitrary complicated expressions that compute (or foo
"").  What's your point?

Andreas.

-- 
Andreas Schwab, schwab <at> linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Message #20 received at 19975 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Andreas Schwab <schwab <at> linux-m68k.org>
Cc: 19975 <at> debbugs.gnu.org, Drew Adams <drew.adams <at> oracle.com>
Subject: Re: bug#19975: 25.0.50;
 Add %s-like descriptor to `format' that treats nil like empty string
Date: Sat, 30 Apr 2016 19:10:11 +0200

Andreas Schwab <schwab <at> linux-m68k.org> writes:

> Drew Adams <drew.adams <at> oracle.com> writes:
>
>> Enhancement request.  Add a new format descriptor to `format' that would
>> behave just like %s except that a nil argument would be treated as if it
>> were "".
>
> It's easy enough to use (or foo "").

Yes, I don't think that we want to clutter up the `format' language with
something as special as this.  Closing.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

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