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From: Drew Adams <drew.adams@oracle.com>
To: JD Smith <jdtsmith@gmail.com>, Stefan Monnier <monnier@iro.umontreal.ca>
Cc: "emacs-devel@gnu.org" <emacs-devel@gnu.org>
Subject: RE: [External] : Re: Code for cond*
Date: Wed, 24 Jan 2024 16:30:01 +0000	[thread overview]
Message-ID: <SJ0PR10MB54888A62EB6D04026A406136F37B2@SJ0PR10MB5488.namprd10.prod.outlook.com> (raw)
In-Reply-To: <1AD5807F-91F7-4B92-BCB0-D0FEA904A75D@gmail.com>

> But oddly enough, this thread discussing its potential
> replacement has given me the key insight — “imagine
> running list interpolation backwards”.  With that mental
> model, I find I can now read pcase forms much more easily
> and confidently.
>
> A short introductory paragraph in the elisp pcase
> documentation which explains this approach to its novel
> syntax would have gone a long way for me.

Indeed, this is the place for the pcase doc to
_start_.  Unfortunately, the doc doesn't do that.

There _is_ a pcase doc _subnode_ that covers such
pattern-matching destructuring, but this should
be up-front.  It's _the most important_ feature
to point out and make clear.  It's the easiest to
grasp and the most useful for understanding the
rest.

The subnode covering destructuring is the very
_last_ one, "Destructuring with pcase Patterns":

https://www.gnu.org/software/emacs/manual/html_node/elisp/Destructuring-with-pcase-Patterns.html
___

I specifically suggested such doc improvements
in an enhancement request, but they were
unfortunately summarily dismissed just a few
minutes after the suggestion was received:

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=68029#13

About this I said, e.g.:

  Such advantages should start with DESTRUCTURING -
  the ONE thing you _don't_ have built-in with the
  existing Elisp binding forms or conditional forms.

  Start with a simple destructuring example:
  `case'-like, but with destructuring.  That's my
  advice.

  Destructuring is the easiest & most powerful `pcase'
  feature to introduce, and it's not really shown.
  It's glossed over, at best.  Show beginners that, to
  start with.

  In a nutshell, `pase-let' vs `let' is really the
  place to start.  _Then_ add conditional control into
  the mix.

  [The current top-level, beginning `pcase' doc is] as
  if someone only tried to explain away some of what
  is particularly confusing about `pcase', instead of
  teaching the strengths of `pcase'.

  parent reply	other threads:[~2024-01-24 16:30 UTC|newest]

Thread overview: 134+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-18  3:37 Code for cond* Richard Stallman
2024-01-18  4:59 ` Emanuel Berg
2024-01-20  3:39   ` Richard Stallman
2024-01-24 12:37     ` Po Lu
2024-01-24 19:12     ` Alan Mackenzie
2024-01-27  3:35       ` Richard Stallman
2024-01-18 15:44 ` Andrea Corallo
2024-01-19 10:42   ` João Távora
2024-01-21  3:04     ` Richard Stallman
2024-01-21 20:05       ` Adam Porter
2024-01-22  5:32         ` tomas
2024-01-23 13:39         ` Richard Stallman
2024-01-24  6:02           ` Po Lu
2024-01-24  9:48       ` Stefan Kangas
2024-01-24 10:09         ` Emanuel Berg
2024-01-24 11:30         ` João Távora
2024-01-24 12:08           ` João Távora
2024-01-24 12:09         ` Po Lu
2024-01-24 12:22           ` Ihor Radchenko
2024-01-24 12:33             ` Po Lu
2024-01-24 13:34               ` Ihor Radchenko
2024-01-24 13:52                 ` João Távora
2024-01-24 14:31                   ` Po Lu
2024-01-27  3:35                   ` Richard Stallman
2024-01-27  3:35                   ` Richard Stallman
2024-01-24 14:07                 ` Po Lu
2024-01-24 14:20                   ` Ihor Radchenko
2024-01-24 14:34                     ` Po Lu
2024-01-24 14:44                       ` Ihor Radchenko
2024-01-24 14:47                         ` João Távora
2024-01-24 15:28                         ` Emanuel Berg
2024-01-24 16:30                           ` Ihor Radchenko
2024-01-24 16:34                             ` Emanuel Berg
2024-01-25  9:06                           ` Po Lu
2024-01-25  9:55                             ` Alfred M. Szmidt
2024-01-25 10:38                               ` Eli Zaretskii
2024-01-25 11:29                               ` Po Lu
2024-01-25 12:04                                 ` Emanuel Berg
2024-01-25 13:32                                   ` Po Lu
2024-01-25 14:08                                     ` Emanuel Berg
2024-01-25 13:19                                 ` Alfred M. Szmidt
2024-01-25 13:43                                   ` Emanuel Berg
2024-01-25 14:31                                     ` Eli Zaretskii
2024-01-25 15:02                                       ` Emanuel Berg
2024-01-25 15:29                                         ` Eli Zaretskii
2024-01-25 15:33                                           ` Alfred M. Szmidt
2024-01-25 15:50                                             ` Eli Zaretskii
2024-01-25 16:01                                               ` Alfred M. Szmidt
2024-01-25 16:13                                                 ` Eli Zaretskii
2024-01-25 15:40                                           ` Emanuel Berg
2024-01-25 10:30                             ` Eli Zaretskii
2024-01-25 11:27                               ` Emanuel Berg
2024-01-24 12:15         ` Alan Mackenzie
2024-01-24 12:28           ` Emanuel Berg
2024-01-25  9:10           ` Po Lu
2024-01-25 11:56             ` Emanuel Berg
2024-01-25 13:21               ` Po Lu
2024-01-25 13:56                 ` Emanuel Berg
2024-01-25 23:32           ` Stefan Kangas
2024-01-20  3:39   ` Richard Stallman
2024-01-23 18:10 ` Stefan Monnier via Emacs development discussions.
2024-01-24  4:49   ` JD Smith
2024-01-24  9:45     ` Stefan Kangas
2024-01-24 15:29       ` JD Smith
2024-01-24 15:55         ` Stefan Monnier
2024-01-24 16:02           ` Stefan Monnier
2024-01-24 16:20           ` JD Smith
2024-01-24 17:08             ` Stefan Monnier
2024-01-24 16:35           ` [External] : " Drew Adams
2024-01-24 16:30     ` Drew Adams [this message]
2024-02-01  8:56       ` Madhu
2024-02-01 22:46         ` Emanuel Berg
2024-01-25  3:16     ` Madhu
2024-01-25 13:57       ` Stefan Monnier
2024-01-25 15:17         ` JD Smith
2024-01-25 15:37           ` JD Smith
2024-01-25 15:44             ` Alfred M. Szmidt
2024-01-25 16:00               ` JD Smith
2024-01-25 16:05               ` Stefan Monnier
2024-01-25 16:12                 ` Alfred M. Szmidt
2024-01-25 16:20                   ` Stefan Monnier
2024-01-25 16:33                   ` JD Smith
2024-01-29  3:19             ` Richard Stallman
2024-01-26  4:30   ` Richard Stallman
2024-01-28  3:06     ` Stefan Monnier via Emacs development discussions.
2024-01-30  3:59       ` Richard Stallman
2024-01-30 13:02         ` Stefan Monnier
2024-02-23  3:04           ` Richard Stallman
2024-01-26  4:30   ` Richard Stallman
2024-01-28  4:16     ` Stefan Monnier via Emacs development discussions.
2024-01-31  3:32       ` Richard Stallman
2024-01-31 13:20         ` Stefan Monnier
2024-02-03  3:32           ` Richard Stallman
2024-02-03  6:09             ` Stefan Monnier
2024-02-03  6:48               ` Emanuel Berg
2024-02-04  4:46               ` Richard Stallman
2024-02-04 14:04                 ` Stefan Monnier
2024-02-04  4:46               ` Richard Stallman
2024-02-04 13:58                 ` Stefan Monnier
2024-02-13  0:48                 ` Stefan Monnier
2024-02-13  2:27                   ` Stefan Monnier
2024-02-14 11:16                   ` Richard Stallman
2024-02-14 12:45                     ` Stefan Monnier
2024-02-22  3:05                       ` Richard Stallman
2024-02-22  4:08                         ` Stefan Monnier
2024-02-25  3:14                           ` Richard Stallman
2024-02-25 15:03                             ` Stefan Monnier
2024-02-29  3:50                               ` Richard Stallman
2024-02-29 18:07                                 ` Stefan Monnier
2024-02-29  3:50                               ` Richard Stallman
2024-02-13  0:41         ` Stefan Monnier
2024-02-23  3:04           ` Richard Stallman
2024-02-23 13:39             ` Stefan Monnier
2024-02-25  3:16               ` Richard Stallman
2024-02-25 14:57                 ` Alfred M. Szmidt
2024-02-25 15:38                   ` Stefan Monnier
2024-02-25 16:42                     ` Alfred M. Szmidt
2024-02-25 17:13                       ` Stefan Monnier
2024-02-25 17:22                     ` Alan Mackenzie
2024-02-25 17:46                       ` Alfred M. Szmidt
2024-02-25 18:13                         ` Stefan Monnier
2024-02-25 17:10                 ` Stefan Monnier
2024-02-27  3:11                   ` Richard Stallman
2024-01-24 12:39 ` Alan Mackenzie
2024-01-24 14:43   ` Emanuel Berg
2024-01-24 16:25   ` Manuel Giraud via Emacs development discussions.
2024-01-25 14:01   ` Code for cond* - cond*-match, cond*-subpat and backtrack-aliases Alan Mackenzie
2024-01-29  3:19     ` Richard Stallman
2024-01-29 12:16       ` JD Smith
2024-02-01  3:51         ` Richard Stallman
2024-02-01 14:54           ` JD Smith
2024-02-04  4:42             ` Richard Stallman
2024-01-29  3:19     ` Richard Stallman
2024-01-29  8:54       ` Andreas Schwab

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