From: HiPhish <hiphish@posteo.de>
To: Mark H Weaver <mhw@netris.org>
Cc: guile-user@gnu.org
Subject: Re: A value for "nothing"
Date: Mon, 27 Aug 2018 10:40:05 +0200 [thread overview]
Message-ID: <15511073.3h7x93ioX3@aleksandar-ixtreme-m5740> (raw)
In-Reply-To: <87ftz0vidc.fsf@netris.org>
I think I understand: it just so happens that `(if #f #f)` evaluates to
`#<unspecified>`, but it would still be valid if it evaluated to 5 or
"roflcopter".
> "The return value of a function that returns nothing" is a
> self-contradictory notion, if you think about it :)
I was under the impression that in Lisp any S-expression evaluates to
*something*, even if that something is some junk value or "nothing".
> I would suggest using a symbol. How about 'nil?
I was considering the possibility of serialising symbols as strings, but then
'nil would be indistinguishable from the string "nil". The more I think about,
the more a singleton instance of a custom record makes sense.
next prev parent reply other threads:[~2018-08-27 8:40 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-26 10:13 A value for "nothing" HiPhish
2018-08-26 17:21 ` Thomas Morley
2018-08-26 17:27 ` Joshua Branson
2018-08-26 17:49 ` John Cowan
2018-08-27 4:52 ` Mark H Weaver
2018-08-27 13:00 ` John Cowan
2018-08-27 21:29 ` Mark H Weaver
2018-08-27 21:32 ` Mark H Weaver
2018-08-26 20:07 ` Mark H Weaver
2018-08-26 22:08 ` Matt Wette
2018-08-27 8:04 ` tomas
2018-08-27 20:12 ` Mark H Weaver
2018-08-27 20:46 ` Mark H Weaver
2018-08-28 0:50 ` Matt Wette
2018-08-28 6:58 ` Mark H Weaver
2018-08-28 15:19 ` John Cowan
2018-08-28 15:38 ` Mark H Weaver
2018-08-28 15:59 ` Mark H Weaver
2018-08-28 16:12 ` John Cowan
2018-08-28 17:15 ` Mark H Weaver
2018-08-28 19:07 ` Mark H Weaver
2018-08-27 20:54 ` Hans Åberg
2018-08-27 0:17 ` Panicz Maciej Godek
2018-08-27 8:02 ` tomas
2018-08-27 8:29 ` Panicz Maciej Godek
2018-08-27 8:29 ` HiPhish
[not found] ` <8840615.kRvQfVdCvZ@aleksandar-ixtreme-m5740>
[not found] ` <CAD2gp_QLqd=_RbF=HTEbCLp1onmUq-c74g0FXTvMgdz8JB4-8A@mail.gmail.com>
2018-08-27 8:24 ` HiPhish
[not found] ` <3467110.H24gZIzStD@aleksandar-ixtreme-m5740>
[not found] ` <87ftz0vidc.fsf@netris.org>
2018-08-27 8:40 ` HiPhish [this message]
2018-08-27 12:37 ` Ludovic Courtès
2018-08-27 19:49 ` Mark H Weaver
2018-08-28 7:52 ` Ludovic Courtès
-- strict thread matches above, loose matches on Subject: below --
2018-08-26 20:25 HiPhish
2018-09-13 21:49 HiPhish
[not found] ` <CAD2gp_Sg-aDXZKfOcL-i2py7ne4c0Cp+2HvKS4DYi1Antm_B1A@mail.gmail.com>
2018-09-14 22:45 ` HiPhish
2018-09-15 0:26 ` John Cowan
2018-09-15 14:50 ` HiPhish
2018-09-15 18:28 ` Keith Wright
2018-09-15 21:50 ` Edwin Watkeys
2018-09-15 22:16 ` HiPhish
2018-09-15 22:23 ` Edwin Watkeys
2018-09-15 22:13 ` HiPhish
2018-09-15 22:45 ` David Pirotte
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