Maybe macros John Cowan (26 Jun 2020 17:16 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (26 Jun 2020 17:43 UTC)
Re: Maybe macros John Cowan (26 Jun 2020 18:48 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (26 Jun 2020 18:57 UTC)
Re: Maybe macros John Cowan (27 Jun 2020 04:29 UTC)
Re: Maybe macros Arthur A. Gleckler (26 Jun 2020 19:50 UTC)
Re: Maybe macros John Cowan (26 Jun 2020 19:52 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (27 Jun 2020 03:44 UTC)
Re: Maybe macros Arthur A. Gleckler (27 Jun 2020 03:59 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (27 Jun 2020 04:15 UTC)
Re: Maybe macros Arthur A. Gleckler (27 Jun 2020 04:29 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (27 Jun 2020 14:09 UTC)
Re: Maybe macros John Cowan (27 Jun 2020 18:55 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (27 Jun 2020 20:46 UTC)
Re: Maybe macros John Cowan (27 Jun 2020 21:34 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (28 Jun 2020 17:26 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (28 Jun 2020 17:43 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (28 Jun 2020 18:52 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (28 Jun 2020 20:24 UTC)
Re: Maybe macros John Cowan (28 Jun 2020 18:54 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (28 Jun 2020 20:21 UTC)
Re: Maybe macros Alex Shinn (29 Jun 2020 00:02 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (29 Jun 2020 06:23 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (28 Jun 2020 16:54 UTC)

Re: Maybe macros Wolfgang Corcoran-Mathe 28 Jun 2020 16:54 UTC

On 2020-06-27 14:55 -0400, John Cowan wrote:
> Sounds good to me.   So the list of new macros is maybe-and, maybe-or,
> maybe-and-let* (more verbose but clearer), and their either-* analogues.
> I'll add these to SRFI 189 when I have a chance.

Excellent.

> I don't think we need -each-in-list if we define -and to work that way: it
> returns the first Nothing/Left if there is one, or the last Just/Right if
> there isn't.  This is exactly how standard Scheme `and` works.  If there
> are no arguments, you get a wrapped #t.

Yes, exactly.  My purpose in mentioning the -each/-each-in-list idioms
was that their role is, I think, best played in SRFI 189 by the
-and/-or forms.

--
Wolfgang Corcoran-Mathe  <xxxxxx@sigwinch.xyz>

"In every work of genius we recognize our own rejected thoughts;
they come back to us with a certain alienated majesty."
--Ralph Waldo Emerson