From: Barry Margolin <barmar@alum.mit.edu>
To: help-gnu-emacs@gnu.org
Subject: Re: Why is booleanp defined this way?
Date: Fri, 17 Apr 2015 23:13:49 -0400 [thread overview]
Message-ID: <barmar-DE640A.23134917042015@88-209-239-213.giganet.hu> (raw)
In-Reply-To: 87k2xamfkg.fsf@kuiper.lan.informatimago.com
In article <87k2xamfkg.fsf@kuiper.lan.informatimago.com>,
"Pascal J. Bourguignon" <pjb@informatimago.com> wrote:
> Emanuel Berg <embe8573@student.uu.se> writes:
>
> > Barry Margolin <barmar@alum.mit.edu> writes:
> >
> >> (booleanp nil) => (nil t)
> >> (booleanp t) => (t)
> >> (booleanp something-else) => nil
>
> And even if that was true, that would still be a valid implementation,
> since both (nil t) and (t) are generalized booleans that are true!
That's what I said in my post. When used in a boolean context, a
generalized boolean is fine. But it would be confusing when used in a
REPL.
--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
next prev parent reply other threads:[~2015-04-18 3:13 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.946.1429302909.904.help-gnu-emacs@gnu.org>
2015-04-17 20:55 ` Why is booleanp defined this way? Pascal J. Bourguignon
2015-04-17 23:20 ` Barry Margolin
2015-04-17 23:30 ` Emanuel Berg
2015-04-18 0:43 ` Pascal J. Bourguignon
2015-04-18 3:13 ` Barry Margolin [this message]
2015-04-18 3:12 ` Barry Margolin
2015-04-18 2:01 ` Rusi
2015-04-18 2:23 ` Emanuel Berg
2015-04-18 2:33 ` Rusi
2015-04-18 2:55 ` Emanuel Berg
2015-04-18 3:11 ` Barry Margolin
2015-04-18 3:35 ` Rusi
2015-04-18 4:56 ` Barry Margolin
2015-04-19 23:08 ` Emanuel Berg
2015-04-19 23:00 ` Emanuel Berg
2015-04-18 21:24 ` Emanuel Berg
2015-04-18 7:52 ` Marcin Borkowski
[not found] ` <mailman.997.1429343558.904.help-gnu-emacs@gnu.org>
2015-04-18 12:43 ` Rusi
2015-04-18 4:09 ` Pascal J. Bourguignon
2015-04-18 5:00 ` Rusi
2015-04-18 3:50 ` Pascal J. Bourguignon
2015-04-18 5:03 ` Stefan Monnier
2015-04-17 20:34 Marcin Borkowski
2015-04-17 20:49 ` Jorge A. Alfaro-Murillo
[not found] ` <mailman.962.1429303822.904.help-gnu-emacs@gnu.org>
2015-04-17 23:06 ` Emanuel Berg
2015-04-18 0:41 ` Pascal J. Bourguignon
2015-04-18 1:06 ` Emanuel Berg
2015-04-18 1:23 ` Pascal J. Bourguignon
2015-04-18 7:44 ` Marcin Borkowski
2015-04-18 8:37 ` Stefan Nobis
2015-04-19 23:15 ` Emanuel Berg
2015-04-18 2:37 ` Drew Adams
2015-04-18 6:13 ` Tassilo Horn
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