unofficial mirror of guile-user@gnu.org 
 help / color / mirror / Atom feed
From: Matt Wette <matt.wette@gmail.com>
To: Guile User <guile-user@gnu.org>
Subject: syntax taste: use of unquote in macros
Date: Sun, 29 Mar 2020 08:11:12 -0700	[thread overview]
Message-ID: <dd403a66-123b-2855-39cb-7b5c5f36cd9a@gmail.com> (raw)

Hi All,

I'm not sure if you know about this, but there is a discrepancy in the
way some folks define macros to use unquote (aka ,).   For example,

 > (use-modules (system base pmatch))
 > (pmatch '(foo "bar")  ((foo ,val)  (write val) (newline)))
=> "bar"

 > (use-modules (ice-9 match))
 > (match '(foo "bar")  (`(foo ,val)  (write val) (newline)))
=> "bar"

Note the difference in the use of quasiquote (aka `) in the pattern
for (foo ,val): match syntax uses it, pmatch does not.
In Scheme, quasiquote and unquote always come together.

Is pmatch syntax in bad taste?  I'm looking for opinions.

Another example is sxml-match, which omits use of quasiquote.
I have written a variation of sxml-match.  Should I keep the sxml-match
usage, which keeps it compatible with sxml-match,  or adopt that
used by (ice-9 match)?

Matt




             reply	other threads:[~2020-03-29 15:11 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-29 15:11 Matt Wette [this message]
2020-03-29 22:07 ` syntax taste: use of unquote in macros Zelphir Kaltstahl
2020-03-30 10:34   ` tomas
2020-03-30 23:43     ` Matt Wette
2020-03-31  9:19       ` tomas
2020-03-30 13:07 ` Arne Babenhauserheide
2020-03-31 16:56 ` Ludovic Courtès

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=dd403a66-123b-2855-39cb-7b5c5f36cd9a@gmail.com \
    --to=matt.wette@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).