From: Ari Roponen <ari.roponen@gmail.com>
To: 13345@debbugs.gnu.org
Subject: bug#13345: 24.2.91; Wrong assumption in a hash table example + fix
Date: Thu, 03 Jan 2013 14:01:17 +0200 [thread overview]
Message-ID: <87lica79wy.fsf@arirop.lan> (raw)
In file doc/lispref/hash.texi, there is an example:
@example
(defun case-fold-string= (a b)
(compare-strings a nil nil b nil nil t))
(defun case-fold-string-hash (a)
(sxhash (upcase a)))
(define-hash-table-test 'case-fold
'case-fold-string= 'case-fold-string-hash)
(make-hash-table :test 'case-fold)
@end example
The documentation of `define-hash-table-test' says:
The function @var{test-fn} should accept two arguments, two keys, and
return non-@code{nil} if they are considered ``the same''.
In the above example, the test function returns always non-nil, because
it assumes `compare-strings' returns nil for differing strings. The
patch below fixes this wrong assumption.
2013-01-03 Ari Roponen <ari.roponen@gmail.com> (tiny change)
* hash.texi (Defining Hash): Fix example.
=== modified file 'doc/lispref/hash.texi'
--- doc/lispref/hash.texi 2013-01-01 09:11:05 +0000
+++ doc/lispref/hash.texi 2013-01-03 10:50:19 +0000
@@ -293,7 +293,7 @@
@example
(defun case-fold-string= (a b)
- (compare-strings a nil nil b nil nil t))
+ (eq t (compare-strings a nil nil b nil nil t)))
(defun case-fold-string-hash (a)
(sxhash (upcase a)))
In GNU Emacs 24.2.91.9 (x86_64-unknown-linux-gnu, GTK+ Version 3.7.2)
of 2013-01-03 on arirop
Bzr revision: 111125 rgm@gnu.org-20130103063325-sx99hs1usiuqlxvb
Windowing system distributor `Fedora Project', version 11.0.11300000
System Description: Fedora release 18 (Spherical Cow)
--
Ari Roponen
next reply other threads:[~2013-01-03 12:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-03 12:01 Ari Roponen [this message]
2013-01-03 18:41 ` bug#13345: 24.2.91; Wrong assumption in a hash table example + fix Glenn Morris
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/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87lica79wy.fsf@arirop.lan \
--to=ari.roponen@gmail.com \
--cc=13345@debbugs.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.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
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).