From: Philip McGrath <philip@philipmcgrath.com>
To: guile-user <guile-user@gnu.org>
Subject: Equality and hashing for new datatypes
Date: Wed, 21 Jun 2023 18:25:29 -0400 [thread overview]
Message-ID: <3759578.e9J7NaK4W3@bastet> (raw)
[-- Attachment #1: Type: text/plain, Size: 1029 bytes --]
Hi,
What is the recommended way for a library to customize `equal?` and `equal?`
-based hashing for new datatypes it defines?
I know from [1] that `equal?` can be customized using GOOPS; however, some
projects do not use GOOPS (e.g. [2]), so it would seem more friendly for a
generic library to avoid it. Also, it is not clear if the same mechanism is
even an option for customizing `equal-hash` to match `equal?`.
I'm looking for something like Racket's `gen:equal+hash` [3] or Chez Scheme's
`record-equal-procedure` and `record-hash-procedure` [4].
This came up while I was working on a portable version of the immutable
hash-table implementations from Racket-on-Chez.
-Philip
[1]: https://www.gnu.org/software/guile/manual/html_node/GOOPS-Object-Miscellany.html
[2]: https://lists.gnu.org/archive/html/info-gnu/2023-05/msg00005.html
[3]: https://docs.racket-lang.org/reference/Equality.html#%28part._.Implementing_.Equality_for_.Custom_.Types%29
[4]: https://cisco.github.io/ChezScheme/csug9.5/objects.html#./objects:h14
[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next reply other threads:[~2023-06-21 22:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-21 22:25 Philip McGrath [this message]
2023-06-22 11:33 ` Equality and hashing for new datatypes Taylan Kammer
2023-06-22 22:45 ` Philip McGrath
2023-06-23 7:09 ` Taylan Kammer
2023-06-23 12:46 ` Robby Zambito
2023-06-25 18:54 ` Jean Abou Samra
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=3759578.e9J7NaK4W3@bastet \
--to=philip@philipmcgrath.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).