unofficial mirror of guile-user@gnu.org 
 help / color / mirror / Atom feed
From: Panicz Maciej Godek <godek.maciek@gmail.com>
To: Panicz Maciej Godek <godek.maciek@gmail.com>,
	"guile-user@gnu.org" <guile-user@gnu.org>
Subject: Re: and-let* is not composable?
Date: Sat, 5 Oct 2013 00:27:27 +0200	[thread overview]
Message-ID: <CAMFYt2boCYdC9ntfFuN2ZbgZAqzBVZZPj7W_66-b+W9m5x=fwQ@mail.gmail.com> (raw)
In-Reply-To: <8761u7o3n3.fsf@Kagami.home>

[-- Attachment #1: Type: text/plain, Size: 1498 bytes --]

>
> If you, or the other people who are confused by syntax-case, can point
> to the parts of the manual that confuse you, so we can clear them up, I
> think we'd all appreciate it.
>
> Fundamentally, syntax-case shouldn't be harder to use than define-macro
> 99% of the time, if you remember
>

As a little addendum to that topic, I just ran across Matthew Flatt's
presentation of Racket macro system,
http://www.infoq.com/presentations/racket,
where he points to a quite good introduction to "define-syntax" macros
by Greg Hendershott: http://www.greghendershott.com/fear-of-macros/

And now that my head is clearer on this regard, I think it is confusing
to call them "syntax-case" macros, because "syntax-case" is rather
auxiliary than essential for defining that sort of macro.

The order of presentation in the manual resembles the one that Hendershott
criticises, namely: first, the syntax-rules macros are presented, which are
an
epiphany once you comprehend them, and then syntax-case is presented as
a different type of macro. However, syntax-case is only a pleasant way to
destructure syntactic information passed to a transformer, and the same
effect could be achieved without using it, by using some more explicit
procedures like syntax->datum. (Furthermore, Hendershott explains
more specifically how do the syntax objects differ from raw scheme forms).
So I believe that at least placing a link to than explanation in the manual
could be a great help for beginners.

Best regards,
M.

[-- Attachment #2: Type: text/html, Size: 2210 bytes --]

  parent reply	other threads:[~2013-10-04 22:27 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-09 17:35 and-let* is not composable? Panicz Maciej Godek
2013-09-09 20:26 ` Stefan Israelsson Tampe
2013-09-09 21:34   ` Ian Price
2013-09-10 13:42     ` Stefan Israelsson Tampe
2013-09-10 13:51       ` Ian Price
2013-11-02  2:39     ` Ian Price
2013-11-02 19:01       ` Ian Price
2013-09-10 17:57 ` Ian Price
2013-09-11 12:25   ` Panicz Maciej Godek
2013-09-11 14:05     ` Ian Price
2013-09-13 18:40       ` Panicz Maciej Godek
2013-09-14  8:19         ` Stefan Israelsson Tampe
2013-10-04 22:27       ` Panicz Maciej Godek [this message]
2013-10-05  8:00         ` Ian Price

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/guile/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAMFYt2boCYdC9ntfFuN2ZbgZAqzBVZZPj7W_66-b+W9m5x=fwQ@mail.gmail.com' \
    --to=godek.maciek@gmail.com \
    --cc=guile-user@gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).