whitespace issues

[Rusi]

I have two somewhat related questions, both around whitespace:

1. Is it possible to have some sort of save-hook so that all leading (indentation) whitespace is cleaned up to space alone and tabs are removed?


2. How to make a dirty crlf file in emacs?
By dirty I mean, some lines ending LF (ie Unix) and some ending CRLF (ie DOS)
[This is to test that such dirty-files are not add-able into git]

[to...@tuxteam.de]

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On Tue, Jun 30, 2015 at 07:17:39AM -0700, Rusi wrote:
> I have two somewhat related questions, both around whitespace:
>
> 1. Is it possible to have some sort of save-hook so that all leading (indentation) whitespace is cleaned up to space alone and tabs are removed?

I'll leave that to more knowledgeable.

> 2. How to make a dirty crlf file in emacs?
> By dirty I mean, some lines ending LF (ie Unix) and some ending CRLF (ie DOS)
> [This is to test that such dirty-files are not add-able into git]

Since CR == CTLR-M, create a file with a buffer coding system
whatever-nix (e.g. utf8-unix). This is the default on a sensible
operating system anyway :-)

At the end of a line, type CTRL-Q CTRL-M -- voilà, this line has crlf
at its end. Check either with hexl-mode, or outside Emacs with hexdump -C.

regards
- -- t
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[Rusi]

On Tuesday, June 30, 2015 at 8:24:46 PM UTC+5:30, to...@tuxteam.de wrote:
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>
> On Tue, Jun 30, 2015 at 07:17:39AM -0700, Rusi wrote:
> > I have two somewhat related questions, both around whitespace:
> >
> > 1. Is it possible to have some sort of save-hook so that all leading (indentation) whitespace is cleaned up to space alone and tabs are removed?
>
> I'll leave that to more knowledgeable.
>
> > 2. How to make a dirty crlf file in emacs?
> > By dirty I mean, some lines ending LF (ie Unix) and some ending CRLF (ie DOS)
> > [This is to test that such dirty-files are not add-able into git]
>
> Since CR == CTLR-M, create a file with a buffer coding system
> whatever-nix (e.g. utf8-unix). This is the default on a sensible
> operating system anyway :-)
>
> At the end of a line, type CTRL-Q CTRL-M -- voilà, this line has crlf
> at its end. Check either with hexl-mode, or outside Emacs with hexdump -C.

Neat! Thanks!
[Its 2015 and our version systems cant get this right]

[Jorge A. Alfaro-Murillo]

Rusi writes:

> I have two somewhat related questions, both around whitespace:
>
> 1. Is it possible to have some sort of save-hook so that all
> leading (indentation) whitespace is cleaned up to space alone
> and tabs are removed?

(add-hook 'before-save-hook
(lambda () (save-excursion (untabify (point-min)
(point-max)))))

> 2. How to make a dirty crlf file in emacs? By dirty I mean, some
> lines ending LF (ie Unix) and some ending CRLF (ie DOS) [This is
> to test that such dirty-files are not add-able into git]

This I don't know.

Best,
--
Jorge.

[Óscar Fuentes]

Rusi <rusto...@gmail.com> writes:

> I have two somewhat related questions, both around whitespace:
>
> 1. Is it possible to have some sort of save-hook so that all leading
> (indentation) whitespace is cleaned up to space alone and tabs are
> removed?

https://github.com/purcell/whitespace-cleanup-mode

I use https://github.com/lewang/ws-butler which smarter in the sense
that only cleans the lines you touched.

[snip]

[Ian Zimmerman]

On 2015-06-30 07:17 -0700, Rusi wrote:

> 1. Is it possible to have some sort of save-hook so that all leading
> (indentation) whitespace is cleaned up to space alone and tabs are
> removed?

Yes, see write-file-functions and untabify

> 2. How to make a dirty crlf file in emacs? By dirty I mean, some
> lines ending LF (ie Unix) and some ending CRLF (ie DOS)

Emacs is probably the wrong tool for this, I would try some combination
of sed, tr, awk, jot

--
Please *no* private copies of mailing list or newsgroup messages.
Rule 420: All persons more than eight miles high to leave the court.

[Rusi]

On Tuesday, June 30, 2015 at 8:32:21 PM UTC+5:30, Jorge A. Alfaro-Murillo wrote:
> Rusi writes:
>
> > I have two somewhat related questions, both around whitespace:
> >
> > 1. Is it possible to have some sort of save-hook so that all
> > leading (indentation) whitespace is cleaned up to space alone
> > and tabs are removed?
>
> (add-hook 'before-save-hook
> (lambda () (save-excursion (untabify (point-min)
> (point-max)))))

How to have this only for (say) python-mode?

[Dan Espen]

Rusi <rusto...@gmail.com> writes:

> I have two somewhat related questions, both around whitespace:
>
> 1. Is it possible to have some sort of save-hook so that all leading
> (indentation) whitespace is cleaned up to space alone and tabs are
> removed?

Yes, but if you set indent-tabs-mode to nil hitting tab will
insert spaces instead of tabs so you won't have to remove tabs.

--
Dan Espen

[Rasmus]

Rusi <rusto...@gmail.com> writes:

> How to have this only for (say) python-mode?

Condition on the mode, (member major-mode list-of-rm-tab-modes).

Rasmus

--
Warning: Everything saved will be lost

[Emanuel Berg]

Rusi <rusto...@gmail.com> writes:

> 1. Is it possible to have some sort of save-hook so
> that all leading (indentation) whitespace is cleaned
> up to space alone and tabs are removed?

Do this and indentation will be in whitespaces only:

(setq-default indent-tabs-mode nil)

Only in Makefiles you still get tabs - otherwise they
(the Makefiles) won't work.

But to answer your question, yes, you can use
`before-save-hook' and `untabify'.

If you want to add exceptions, it could look like
this:

(defun untab-all ()
(unless (member major-mode '(makefile-gmake-mode
makefile-mode) ) ; exceptions
(untabify (point-min) (point-max)))
nil) ; tell 'did not write buffer to disk'

But I think it is better to have the file as you edit
it be as close to the finished form as possible, and
not have it post-processed like that.

--
underground experts united
http://user.it.uu.se/~embe8573

[Rusi]

On Tuesday, June 30, 2015 at 8:36:37 PM UTC+5:30, Óscar Fuentes wrote:

Thanks Oscar -- looks interesting.
But this is not so much for me as for my kids er... students, and would like to
minimize moving parts like extra installs

[Rusi]

On Wednesday, July 1, 2015 at 4:57:21 AM UTC+5:30, Emanuel Berg wrote:

Ok thanks Emanuel, Jorge
Putting your two together I have

--------------------
(add-hook 'before-save-hook
'untab-python
)

(defun untab-python ()
(when (member major-mode '(python-mode))
(untabify (point-min) (point-max)))
nil)
----------------------

1. dunno about the save-excursion
2. member rather than equal/eq so that other modes can be added as desired

[to...@tuxteam.de]

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On Tue, Jun 30, 2015 at 07:37:17PM -0700, Rusi wrote:
> On Tuesday, June 30, 2015 at 8:36:37 PM UTC+5:30, Óscar Fuentes wrote:
> > Rusi writes:
> >
> > > I have two somewhat related questions, both around whitespace:
> > >
> > > 1. Is it possible to have some sort of save-hook so that all leading
> > > (indentation) whitespace is cleaned up to space alone and tabs are
> > > removed?
> >
> > https://github.com/purcell/whitespace-cleanup-mode

I don't know whether it has been mentioned in the thread, but there's
a "whitespace-cleanup" which is part of the standard Emacs distribution.

I use it from time to time, whenever I suspect that whitespace is
messed up in a file. Very handy.

- -- t
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[Jorge A. Alfaro-Murillo]

Rusi writes:

> 1. dunno about the save-excursion

That makes saves the point, the mark, and the current buffer and
the restores those things after it is done. I don't think you need
it in this case as untabify, point-min and point-max don't move
the point or the mark.

--
Jorge.

[Emanuel Berg]

Rusi <rusto...@gmail.com> writes:

> (add-hook 'before-save-hook
> 'untab-python
> )
>
> (defun untab-python ()
> (when (member major-mode '(python-mode))
> (untabify (point-min) (point-max)))
> nil)
>

> 1. dunno about the save-excursion

You don't need it. Examine `untabify' as that is the
only thing that could possible be the reason to use
it. It isn't, but when in doubt, isolate what is
doubted and test it.

> 2. member rather than equal/eq so that other modes
> can be added as desired

Indeed, however then should it still be named
"untab-python"? Unless there are several Python modes,
which OTOH wouldn't surprise me considering how much
extracurriculuous activity that comes with...