From: Heime <heimeborgia@protonmail.com>
To: Drew Adams <drew.adams@oracle.com>
Cc: Emanuel Berg <incal@dataswamp.org>,
"help-gnu-emacs@gnu.org" <help-gnu-emacs@gnu.org>
Subject: RE: [External] : Re: cond construct for situation when a variable is t
Date: Tue, 22 Aug 2023 20:21:22 +0000 [thread overview]
Message-ID: <oQH90tKTwMXzdSFS0rnnqTCD-3tIDz4nAZaafUvVncXwQqdqqNoDtYEahx2c8bSeVihDQ2vZEP5_kN9wi8ycS7npRgUOW0iBdgxuwWd4VxI=@protonmail.com> (raw)
In-Reply-To: <SJ0PR10MB5488E08C070BEE80C0375ED4F31FA@SJ0PR10MB5488.namprd10.prod.outlook.com>
Sent with Proton Mail secure email.
------- Original Message -------
On Wednesday, August 23rd, 2023 at 4:17 AM, Drew Adams <drew.adams@oracle.com> wrote:
> > There is no 'boolean datatype' in elisp.
> > With nil and empty list () being false,
> > anything else is true.
>
>
> There's no real true or false in Lisp. But yes,
> that's the convention, and that convention is
> baked into primitive conditionals, such as `if' and` cond'. So sure, you can think of it as
> being more than a convention.
>
> > That t is used for true, is that by convention ?
> > Should t be used, or is it unreliable ?
>
>
> Just like the "convention" described above, it's
> a convention. But also just like it, it's baked
> into primitives. So yes, the constant `t' is a
> typical non-nil value used by conditionals to
> represent "true". And it's the canonical way to
> represent "true", meaning that it's the clearest
> way to tell human readers of code that "true" is
> meant.
The canonical convention also stipulates that the symbol
t is not to be modified to something else though, am I right ?
next prev parent reply other threads:[~2023-08-22 20:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-18 14:00 cond construct for situation when a variable is t Heime
2023-08-19 22:04 ` Emanuel Berg
2023-08-22 12:18 ` Heime
2023-08-22 16:10 ` [External] : " Drew Adams
2023-08-22 19:31 ` Emanuel Berg
2023-08-23 19:49 ` Drew Adams
2023-08-22 19:29 ` Emanuel Berg
2023-08-22 12:32 ` Heime
2023-08-22 16:17 ` [External] : " Drew Adams
2023-08-22 20:21 ` Heime [this message]
2023-08-22 21:07 ` Drew Adams
2023-08-19 22:43 ` Rudolf Adamkovič
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