Facundo Batista schrieb:

Georg Brandl wrote:

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Of course, we could also setup a svn pre-commit hook that rejects trailing whitespace >:->

I was about to suggest a mail to python-checkins when a bad whitespace is detected, but had no idea that a pre-commit check existed in SVN.

It'd be great if the system won't let you commit if whitespace is bad.

Well, there are editors that don't intelligently strip whitespace, so that people using them would be constantly pained by such a hook. Things like two-space indents or tabs, however, should really be rejected IMO. Stripping the trailing whitespace automatically on checkin would also be fine, but I don't think that kind of thing is possible with SVN (also, it would mean that your WC is out of date after checkin). Geog -- Thus spake the Lord: Thou shalt indent with four spaces. No more, no less. Four shall be the number of spaces thou shalt indent, and the number of thy indenting shall be four. Eight shalt thou not indent, nor either indent thou two, excepting that thou then proceed to four. Tabs are right out.

>> Well, there are editors that don't intelligently strip whitespace, so >> that people using them would be constantly pained by such a hook. Guido> And they should. There really is no excuse for letting one Guido> developer's poor choice of tools cause later grief for all other Guido> developers. Just a little FYI, python-mode (the one Barry and I manage - dunno about the one distributed w/ GNU Emacs these days) is one of those tools that leaves trailing whitespace behind when advancing to the next line.. Skip

skip> Just a little FYI, python-mode (the one Barry and I manage - dunno skip> about the one distributed w/ GNU Emacs these days) is one of those skip> tools that leaves trailing whitespace behind when advancing to the skip> next line.. At least so I thiought. I know I've seen these turds before, but a quick check wouldn't reproduce it... Skip

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Apr 25, 2007, at 2:37 PM, skip@pobox.com wrote:

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Well, there are editors that don't intelligently strip whitespace, so that people using them would be constantly pained by such a hook.

Guido> And they should. There really is no excuse for letting one Guido> developer's poor choice of tools cause later grief for all other Guido> developers.

Just a little FYI, python-mode (the one Barry and I manage - dunno about the one distributed w/ GNU Emacs these days) is one of those tools that leaves trailing whitespace behind when advancing to the next line..

Maybe we should include this function in the mode: ;; untabify and clean up lines with just whitespace (defun baw-whitespace-normalization () "Like untabify, but also cleans up lines with trailing whitespace." (interactive) (save-excursion (save-restriction (untabify (point-min) (point-max)) (goto-char (point-min)) (while (re-search-forward "[ \t]+$" nil t) (let ((bol (save-excursion (beginning-of-line) (point))) (eol (save-excursion (end-of-line) (point)))) (goto-char (match-beginning 0)) (if (and (bolp) (eq (char-after) ?\)) (forward-char 1)) (skip-chars-backward " \t" bol) (delete-region (point) eol) )) ;; Now clean up any trailing blank lines (goto-char (point-max)) (skip-chars-backward " \t\n") (if (not (bolp)) (forward-char 1)) (delete-region (point) (point-max)) ;; But make sure the files ends in a newline (if (not (bolp)) (newline)) ))) (defalias 'baw-normalize-whitespace 'baw-whitespace-normalization) -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (Darwin) iQCVAwUBRi+2y3EjvBPtnXfVAQKyCAP5AUwHxTgOCRkkgCRfAP/oWCxf1WT/Y1lk PUrb4eRaR2s5B8XP417V3O/uMPHfiQr9Ci1txoIuq22PRbPvOFT4bfSYXFxPrrGS FOlvivpE8rnXSxv4bJC/3B11GNDoyQJds8D4/13XIZXnFE4W2WtyA0fG1kxQXBEc gvjk/FXuRS8= =3Wll -----END PGP SIGNATURE-----

[Skip]

Just a little FYI, python-mode (the one Barry and I manage - dunno about the one distributed w/ GNU Emacs these days) is one of those tools that leaves trailing whitespace behind when advancing to the next line..

Shouldn't be -- unless the behavior of the Emacs newline-and-indent has changed. The pymode version (py-newline-and-indent) relies in part on newline-and-indent; the intent is documented in the py-newline-and-indent docstring: (defun py-newline-and-indent () "... In general, deletes the whitespace before point, inserts a newline, and takes an educated guess as to how you want the new line indented." IIRC, pymode leaves C-j bound to plain old newline, so if you're in the habit of starting a new line via C-j no changes of any kind are made to whitespace. But that's not the intended way to use pymode.

>> Just a little FYI, python-mode (the one Barry and I manage - dunno >> about the one distributed w/ GNU Emacs these days) is one of those >> tools that leaves trailing whitespace behind when advancing to the >> next line.. (See my earlier retraction...) Greg> I get extremely annoyed with editors that *don't* leave whitespace Greg> at the end of lines alone, at least while you're working on the Greg> file. You type part of a line, leave a space, go to copy something Greg> from somewhere else to put on the end, and when you get back, the Greg> space you deliberately left there is gone. That's not the way python-mode works. If I enter this: def f(a): b = a * a @ % then hit LF or RET after the statement, it inserts a newline and inserts enough spaces to leave the cursor where I placed the @ sign. If I hit another LF or RET it removes the "trailing" whitespace on the current line, enters a newline and inserts enough spaces to leave the cursor where I placed the % sign. Greg> Stripping trailing whitespace on saving wouldn't be Greg> so bad, though. Is there an option for that in python-mode? Not by default. You could add a hook to write-file-hooks though. Skip

Guido van Rossum schrieb:

On 4/25/07, Georg Brandl wrote:

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Well, there are editors that don't intelligently strip whitespace, so that people using them would be constantly pained by such a hook.

And they should. There really is no excuse for letting one developer's poor choice of tools cause later grief for all other developers.

Okay, attached is a pre-commit hook script for that purpose. Georg -- Thus spake the Lord: Thou shalt indent with four spaces. No more, no less. Four shall be the number of spaces thou shalt indent, and the number of thy indenting shall be four. Eight shalt thou not indent, nor either indent thou two, excepting that thou then proceed to four. Tabs are right out. #!/usr/bin/env python SVNLOOK = '/usr/bin/svnlook' SCRIPTS_PATH = '/home/gbr/devel/python/Tools/scripts' import sys sys.path.insert(0, SCRIPTS_PATH) _, repos, txn = sys.argv from subprocess import Popen, PIPE from reindent import Reindenter from StringIO import StringIO def get_output(*command): popen = Popen(command, stdout=PIPE) stdout = popen.communicate()[0] if popen.returncode: sys.exit(1) else: return stdout bad = 0 for line in get_output(SVNLOOK, 'changed', '-t', txn, repos).splitlines(): filename = line[4:].strip() if not filename[-3:] == '.py': continue content = StringIO(get_output(SVNLOOK, 'cat', '-t', txn, repos, filename)) reindenter = Reindenter(content) if reindenter.run(): print >>sys.stderr, "file %s is not whitespace-normalized" % filename bad += 1 if bad: sys.exit(1)

Martin v. Löwis schrieb:

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Okay, attached is a pre-commit hook script for that purpose.

How does that deal with deletions?

Ah, you'd have to look at the first two chars of every lines that I cut away.

What do you think about the attached alternative?

I'd say it's better since it uses the Python SVN bindings instead of calling external programs... Georg -- Thus spake the Lord: Thou shalt indent with four spaces. No more, no less. Four shall be the number of spaces thou shalt indent, and the number of thy indenting shall be four. Eight shalt thou not indent, nor either indent thou two, excepting that thou then proceed to four. Tabs are right out.

> Just a little FYI, python-mode (the one Barry and I manage - dunno > about the one distributed w/ GNU Emacs these days) is one of those > tools that leaves trailing whitespace behind when advancing to the > next line.. Okay, I figured this out. The dangling whitespace turds are caused by LF or RET followed by a regular cursor motion keypress (e.g. C-n or the arrow keys) which move the cursor away from that line. Those commands operate outside python-mode's control there so it doesn't get the opportunity to remove the whitespace before moving the cursor. XEmacs (at least) doesn't have a cursor-motion-hook so there's no clean way to do this. I've been using Emacs for so many years that my central control program long ago pushed out most of the basic cursor motion control code to ganglia which reside in my wrists. The channel is full duplex but highly assymetric. The upload speed is very slow. It thus takes a couple days to realize in my frontal cortex how this low level stuff works... Skip

On Wednesday 25 April 2007, Steve Holden wrote:

Duncan Booth wrote:

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That way the whitespace ought to stay normalized so you shouldn't need a separate cleanup step and you won't be breaking diff and blame for the sources (and if the reindent does ever break anything it should be more tracable).

+1

+1 here as well; there's no need to let things like this get out-of-sync from what we want. -Fred -- Fred L. Drake, Jr. <fdrake at acm.org>

On Wed, Apr 25, 2007 at 08:40:22AM +0100, Duncan Booth wrote:

IMHO, changing whitespace retrospectively in a version control system is a bad idea.

In my experience Duncan's assertion is absolutely true, and all the more so in a project that maintains a large body of pending patches, as Python does. Spurious whitespaces changes in the repo will generate patch rejections that will drive both maintainers (as they check in a patch) and submitters (as they try to refresh patches against head) mad. I'm very much interested in VC systems *not* driving developers mad! Dustin

Tim> ... but only when the code mysteriously Tim> relied on significant trailing whitespace in the .py file. Maybe \s should expand to a single space by the lexer so people who want to rely on trailing spaces can be explicit about it. There already exists non-whitespace escape sequences for tabs and newlines. Skip