[PATCH] Trim trailing whitespace in vim and emacs

On 2018-Jun-05, David Fetter wrote:

Hi David

Here's my attempt to $subject. I've tested with vim, but I'm much less
certain I got the EMACS code right.

Is there any interest in such a feature?

I'd rather have the editor warn me (highlight) such things rather than
fix them silently (I wonder if it'd cause a mess with regression .out
files for example, which I do edit on occasion).

I once tried to have vim highlight trailing whitespace, spaces before
tabs, and overlength lines (>80 chars), and while I could do each thing
in isolation, I wasn't able to get it to highlight the three of them at
the same time. If you have a recipe for that, I welcome it.

--
�lvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Alvaro Herrera <alvherre@2ndquadrant.com> writes:

On 2018-Jun-05, David Fetter wrote:

Is there any interest in such a feature?

I'd rather have the editor warn me (highlight) such things rather than
fix them silently (I wonder if it'd cause a mess with regression .out
files for example, which I do edit on occasion).

Yeah, agreed. FWIW, I'm not that fussed about this for .h/.c files,
since pgindent will fix it sooner or later (or even right away, if the
committer is anal enough to pgindent before committing, as some of us
are). It's a bit more of a problem for other file types.

I note that Peter E. seems to have a recipe for finding such issues,
which I suspect is grounded in some obscure git feature or other.
That might be easier to work with, since you'd only need one fix
not one per editor.

regards, tom lane

On Tue, Jun 05, 2018 at 01:28:54PM -0400, Alvaro Herrera wrote:

On 2018-Jun-05, David Fetter wrote:
Hi David

Here's my attempt to $subject. I've tested with vim, but I'm much less
certain I got the EMACS code right.

Is there any interest in such a feature?

I'd rather have the editor warn me (highlight) such things rather than
fix them silently (I wonder if it'd cause a mess with regression .out
files for example, which I do edit on occasion).

For what it's worth, the patch trims trailing whitespace only on
certain types of files in vim and just one (C) in emacs for just this
reason.

I once tried to have vim highlight trailing whitespace, spaces before
tabs, and overlength lines (>80 chars), and while I could do each thing
in isolation, I wasn't able to get it to highlight the three of them at
the same time. If you have a recipe for that, I welcome it.

In vim, one way to do it is:

highlight link sensibleWhitespaceError Error
autocmd Syntax * syntax match sensibleWhitespaceError excludenl /\s\+\%#\@<!$\| \+\ze\t|^.\{81,}/ display containedin=ALL

I'm sure there's something more elegant in emacs, but I'm not sure
what it is.

Best,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778

Remember to vote!
Consider donating to Postgres: http://www.postgresql.org/about/donate

I once tried to have vim highlight trailing whitespace, spaces before
tabs, and overlength lines (>80 chars), and while I could do each thing
in isolation, I wasn't able to get it to highlight the three of them at
the same time. If you have a recipe for that, I welcome it.

I use FileStly plugin to vim [1]https://www.vim.org/scripts/script.php?script_id=5065 -- Teodor Sigaev E-mail: teodor@sigaev.ru WWW: http://www.sigaev.ru/. But I slightly modify it, see in attachment.
And addition in .vimrc:

if expand('%:e') == "c" || expand('%:e') == "h" || expand('%:e') == "cpp" ||
expand('%:e') == "m" || expand('%:e') == "hpp" || expand('%:e') == "pl" ||
expand('%:e') == "pm" || expand('%:e') == "y" || expand('%:e') == "l"
else
let g:filestyle_plugin = 1
endif

[1]: https://www.vim.org/scripts/script.php?script_id=5065 -- Teodor Sigaev E-mail: teodor@sigaev.ru WWW: http://www.sigaev.ru/
--
Teodor Sigaev E-mail: teodor@sigaev.ru
WWW: http://www.sigaev.ru/

I use FileStly plugin to vim [1]. But I slightly modify it,О©╫ see in attachment.

FileStyle, sorry.

--
Teodor Sigaev E-mail: teodor@sigaev.ru
WWW: http://www.sigaev.ru/

On 6/5/18 13:22, David Fetter wrote:

diff --git a/.dir-locals.el b/.dir-locals.el
index 9525d6b604..858461e6bd 100644
--- a/.dir-locals.el
+++ b/.dir-locals.el
@@ -4,7 +4,8 @@
(c-file-style . "bsd")
(fill-column . 78)
(indent-tabs-mode . t)
-            (tab-width . 4)))
+            (tab-width . 4)
+			(lambda () (add-to-list 'write-file-functions 'delete-trailing-whitespace)))))
(dsssl-mode . ((indent-tabs-mode . nil)))
(nxml-mode . ((indent-tabs-mode . nil)))
(perl-mode . ((perl-indent-level . 4)

dir-locals doesn't work this way. It's not a general lisp file.

--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

On 6/5/18 13:37, Tom Lane wrote:

I note that Peter E. seems to have a recipe for finding such issues,
which I suspect is grounded in some obscure git feature or other.
That might be easier to work with, since you'd only need one fix
not one per editor.

I have a git alias:

check-whitespace = !git diff-tree --check $(git hash-object -t tree
/dev/null) HEAD ${1:-$GIT_PREFIX}

Also, in Emacs I use

(global-whitespace-mode 1)
(setq whitespace-style
'(face
trailing empty indentation space-after-tab space-before-tab))

With source code other than PostgreSQL, this will occasionally result in
angry fruit salad.

--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

On 2018-06-05 18:22, David Fetter wrote:

Folks,

Here's my attempt to $subject. I've tested with vim, but I'm much less
certain I got the EMACS code right.

Is there any interest in such a feature?

A few days ago there was a suggestion on this list to add a
.editorconfig file specifying tab width:
/messages/by-id/87efhuz9be.fsf@news-spur.riddles.org.uk

The .editorconfig format also supports a trim_trailing_whitespace option
(see https://editorconfig.org/ ).

So that might be a simpler way to achieve this (I suppose people who
don't want this behaviour just wouldn't configure their editors to
honour .editorconfig files).

-M-

"Peter" == Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:

+ (lambda () (add-to-list 'write-file-functions 'delete-trailing-whitespace)))))

Peter> dir-locals doesn't work this way. It's not a general lisp file.

Right. The correct approach is

+ (eval add-hook 'before-save-hook 'delete-trailing-whitespace nil t)))

(see the value of safe-local-eval-forms for why)

--
Andrew (irc:RhodiumToad)

"Matthew" == Matthew Woodcraft <matthew@woodcraft.me.uk> writes:

Matthew> A few days ago there was a suggestion on this list to add a
Matthew> .editorconfig file specifying tab width:
Matthew> /messages/by-id/87efhuz9be.fsf@news-spur.riddles.org.uk

Matthew> The .editorconfig format also supports a
Matthew> trim_trailing_whitespace option (see https://editorconfig.org/
Matthew> ).

Yes. I was actually planning to ask if any .editorconfig users (of which
I'm not one - my only use for it is to improve display output on github)
would like to contribute the most useful content for such a file.

--
Andrew (irc:RhodiumToad)

On 06/05/2018 05:33 PM, Andrew Gierth wrote:

"Matthew" == Matthew Woodcraft <matthew@woodcraft.me.uk> writes:

Matthew> A few days ago there was a suggestion on this list to add a
Matthew> .editorconfig file specifying tab width:
Matthew> /messages/by-id/87efhuz9be.fsf@news-spur.riddles.org.uk

Matthew> The .editorconfig format also supports a
Matthew> trim_trailing_whitespace option (see https://editorconfig.org/
Matthew> ).

Yes. I was actually planning to ask if any .editorconfig users (of which
I'm not one - my only use for it is to improve display output on github)
would like to contribute the most useful content for such a file.

I'm not one either (yet!) but it seems to me like something worth doing.
It seems to support an impressively large number of editors and display
mechanisms, and adding a single small file to support it doesn't seem
onerous.

cheers

andrew

--
Andrew Dunstan https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services