From: Stefan Monnier <monnier@iro.umontreal.ca>
To: "Fabián Ezequiel Gallina" <fgallina@gnu.org>
Cc: 15295@debbugs.gnu.org
Subject: bug#15295: python mode slow to unusable
Date: Sun, 27 Oct 2013 00:23:51 -0400 [thread overview]
Message-ID: <jwvsivnpcl0.fsf-monnier+emacsbugs@gnu.org> (raw)
In-Reply-To: <87fvrofehi.fsf@web.de> (Michael Heerdegen's message of "Sat, 26 Oct 2013 13:39:21 +0200")
Could you take a look at this, as well?
Stefan
>>>>> "Michael" == Michael Heerdegen <michael_heerdegen@web.de> writes:
> Alex V. Koval <alex@ua2web.com> writes:
>> For me this is happen as well. Emacs, starting from version 24.3 became
>> so slow in Python mode that I had to tell all developers at our company
>> to use version 24.2 until I sorted this out.
>>
>> Sit today and started trying various emacs versions, and calling
>> different functions. The suggested test case from original author above,
>> runs with this benchmark:
>>
>> (7.3956507 53 1.8788885930000063)
> I profiled a bit, and, at least in this example, these two functions
> seem to be extremely inefficient in combination:
> (defun python-nav-beginning-of-statement ()
> "Move to start of current statement."
> (interactive "^")
> (while (and (or (back-to-indentation) t)
> (not (bobp))
> (when (or
> (save-excursion
> (forward-line -1)
> (python-info-line-ends-backslash-p))
> (python-syntax-context 'string)
> (python-syntax-context 'paren))
> (forward-line -1))))
> (point-marker))
> (defun python-info-line-ends-backslash-p (&optional line-number)
> "Return non-nil if current line ends with backslash.
> With optional argument LINE-NUMBER, check that line instead."
> (save-excursion
> (save-restriction
> (widen)
> (when line-number
> (python-util-goto-line line-number))
> (while (and (not (eobp))
> (goto-char (line-end-position))
> (python-syntax-context 'paren)
> (not (equal (char-before (point)) ?\\)))
> (forward-line 1))
> (when (equal (char-before) ?\\)
> (point-marker)))))
> They consume most of the time used. While the first function goes
> backward, the second goes forward to the end in every loop cycle. This
> makes the thing O(n^2), with n being the number of lines of the
> expression.
> I don't know Python, so I can't make any suggestions. Who can? At
> least, changing the order of `or' expressions in
> `python-nav-beginning-of-statement' seems to help in the example case:
> (defun python-nav-beginning-of-statement ()
> "Move to start of current statement."
> (interactive "^")
> (while (and (or (back-to-indentation) t)
> (not (bobp))
> (when (or
> (python-syntax-context 'string)
> (python-syntax-context 'paren)
> (save-excursion
> (forward-line -1)
> (python-info-line-ends-backslash-p)))
> (forward-line -1))))
> (point-marker))
> It's also not efficient how often `syntax-ppss' is called all the time.
> Regards,
> Michael.
next prev parent reply other threads:[~2013-10-27 4:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-07 0:47 bug#15295: which-func-mode slow in long Python tuple Dale
2013-10-26 9:16 ` bug#15295: python mode slow to unusable Alex V. Koval
2013-10-26 11:39 ` Michael Heerdegen
2013-10-27 4:23 ` Stefan Monnier [this message]
2013-10-27 8:01 ` Andreas Röhler
2013-12-24 20:08 ` bug#15295: Fabián Ezequiel Gallina
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
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=jwvsivnpcl0.fsf-monnier+emacsbugs@gnu.org \
--to=monnier@iro.umontreal.ca \
--cc=15295@debbugs.gnu.org \
--cc=fgallina@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 external index
https://git.savannah.gnu.org/cgit/emacs.git
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.