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

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

[Drew Adams]

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@gnu.org-20141020195941-icp42t8ttcnud09g
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --enable-checking=yes,glyphs CPPFLAGS=-DGLYPH_DEBUG=1'

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

[Drew Adams]

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

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

[Andreas Schwab]

Drew Adams <drew.adams@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@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

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

[Drew Adams]

> > 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) "")).

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

[Andreas Schwab]

Drew Adams <drew.adams@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@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

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

[Lars Ingebrigtsen]

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

> Drew Adams <drew.adams@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