non-nil not valid any more?

non-nil not valid any more?

[Andreas Röhler]

Hi,

IIRC it was possible to write something like

(if non-nil (message "%s" "Wahr")(message "%s" "Falsch"))

Now get

Debugger entered--Lisp error: (void-variable non-nil)

GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 2.24.32, 
cairo version 1.16.0) of 2020-06-10

Thanks,
Andreas

Re: non-nil not valid any more?

[tomas]

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On Thu, Jun 11, 2020 at 06:54:23PM +0200, Andreas Röhler wrote:
> Hi,
> 
> IIRC it was possible to write something like
> 
> (if non-nil (message "%s" "Wahr")(message "%s" "Falsch"))

Hm. I didn't know about this one. "My" Emacs calls it `t' ;-)

Now more seriously: what would be the difference between
`non-nil' and '?

Cheers
-- t

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Re: non-nil not valid any more?

[Eli Zaretskii]

> Date: Thu, 11 Jun 2020 19:06:13 +0200
> From: <tomas@tuxteam.de>
> 
> > IIRC it was possible to write something like
> > 
> > (if non-nil (message "%s" "Wahr")(message "%s" "Falsch"))
> 
> Hm. I didn't know about this one. "My" Emacs calls it `t' ;-)

Isn't `t` an obsolete alias for `non-nil`?

Re: non-nil not valid any more?

[Michael Albinus]

Eli Zaretskii <eliz@gnu.org> writes:

>> Date: Thu, 11 Jun 2020 19:06:13 +0200
>> From: <tomas@tuxteam.de>
>>
>> > IIRC it was possible to write something like
>> >
>> > (if non-nil (message "%s" "Wahr")(message "%s" "Falsch"))
>>
>> Hm. I didn't know about this one. "My" Emacs calls it `t' ;-)
>
> Isn't `t` an obsolete alias for `non-nil`?

Not obsolete. It's already removed in master.

Re: non-nil not valid any more?

[Stefan Monnier]

>> Isn't `t` an obsolete alias for `non-nil`?
> Not obsolete. It's already removed in master.

... which was hence renamed `maser`.


        Sefan

RE: non-nil not valid any more?

[Drew Adams]

> >> Isn't `t` an obsolete alias for `non-nil`?
> > Not obsolete. It's already removed in master.
> 
> ... which was hence renamed `maser`.

So `masnon-niler' is no longer supported? ;-)

Re: non-nil not valid any more?

[Michael Heerdegen]

Andreas Röhler <andreas.roehler@easy-emacs.de> writes:

> Hi,
>
> IIRC it was possible to write something like
>
> (if non-nil (message "%s" "Wahr")(message "%s" "Falsch"))
>
> Now get
>
> Debugger entered--Lisp error: (void-variable non-nil)

Are you sure it wasn't quoted:

  (if 'non-nil (message "%s" "Wahr")(message "%s" "Falsch"))

or did you define the symbol `non-nil' as a variable (with a non-nil
value)?  :non-nil would work, too.

Michael.

Re: non-nil not valid any more?

[tomas]

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On Thu, Jun 11, 2020 at 11:00:46AM -0700, Drew Adams wrote:
> > >> Isn't `t` an obsolete alias for `non-nil`?
> > > Not obsolete. It's already removed in master.
> > 
> > ... which was hence renamed `maser`.
> 
> So `masnon-niler' is no longer supported? ;-)

Hey, folks -- you managed to confuse the hell out of me ;-)

Cheers
-- t

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RE: non-nil not valid any more?

[Drew Adams]

> > > >> Isn't `t` an obsolete alias for `non-nil`?
> > > > Not obsolete. It's already removed in master.
> > >
> > > ... which was hence renamed `maser`.
> >
> > So `masnon-niler' is no longer supported? ;-)
> 
> Hey, folks -- you managed to confuse the hell out of me ;-)

Sorry.  I think Stefan was making a joke about
the letter `t' having been removed.  Mine was
just to replace `t' with `non-nil'.  Ignore...

Re: non-nil not valid any more?

[tomas]

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On Thu, Jun 11, 2020 at 12:18:26PM -0700, Drew Adams wrote:
> > > > >> Isn't `t` an obsolete alias for `non-nil`?
> > > > > Not obsolete. It's already removed in master.
> > > >
> > > > ... which was hence renamed `maser`.
> > >
> > > So `masnon-niler' is no longer supported? ;-)
> > 
> > Hey, folks -- you managed to confuse the hell out of me ;-)
> 
> Sorry.  I think Stefan was making a joke about
> the letter `t' having been removed.  Mine was
> just to replace `t' with `non-nil'.  Ignore...

No need to apologize: though initially confused, I had my fun, too :)

Cheers
-- t

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Re: non-nil not valid any more?

[Stefan Monnier]

Hi omas,

> No need o apologize: hough iniially confused, I had my fun, oo :)

Wha?


        Sefan

Re: non-nil not valid any more?

[tomas]

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On Thu, Jun 11, 2020 at 05:19:40PM -0400, Stefan Monnier wrote:
> Hi omas,
> 
> > No need o apologize: hough iniially confused, I had my fun, oo :)
> 
> Wha?

;-D

-- omás

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Re: non-nil not valid any more?

[Andreas Röhler]

On 11.06.20 20:10, Michael Heerdegen wrote:
> Andreas Röhler <andreas.roehler@easy-emacs.de> writes:
>
>> Hi,
>>
>> IIRC it was possible to write something like
>>
>> (if non-nil (message "%s" "Wahr")(message "%s" "Falsch"))
>>
>> Now get
>>
>> Debugger entered--Lisp error: (void-variable non-nil)
> Are you sure it wasn't quoted:
>
>    (if 'non-nil (message "%s" "Wahr")(message "%s" "Falsch"))
>
> or did you define the symbol `non-nil' as a variable (with a non-nil
> value)?  :non-nil would work, too.
>
> Michael.
>

Seems that was a long living mistake. As `t' is a common char, assumed 
in earlier lisp existed nil and non-nil as symbols for true and false.

Re: non-nil not valid any more?

[Michael Heerdegen]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>         Sefan

So we can think of you as a part of Emacs?  Good to know!

Michael.