sh-script.el : don't colorize $(( 4 << 2 )) as here-document

[Thomas Gambier]

Hello,

when I'm writing something like this in bash script value=$(( 4 << 2 )),
Emacs keep thinking it's the beginning of here-document and will
colorize in yellow all the code below this expression.

I've seen that a bug in sh-script.el was corrected so that << between ""
won't be interpreted as a beginning of here-document
(http://lists.gnu.org/archive/html/help-gnu-emacs/2003-06/msg00158.html).
Is there any solution to don't consider also << between $(( )) ? I
looked into sh-script.el to try to correct it myself but I'm not very at
ease with lisp and regular expression and I didn't find what to change.
That's why I ask help here. If it's not possible, I will disable the
feature as explained in the previous link.

Best regards.

--
Thomas Gambier.

[Thomas Gambier]

[Andreas Röhler]

Hi,

AFAIS it's inside

(defconst sh-here-doc-open-re
(concat "<<-?\\s-*\\\\?\\(\\(?:['\"][^'\"]+['\"]\\|\\sw\\)+\\)"
sh-escaped-line-re "\\(\n\\)"))

If you say, `sh-here-doc-open-re' must start at bol or
only permit whitespace before, inserting a ^[ \t]* into
the regexp

(setq sh-here-doc-open-re
(concat "^[ \t]*<<-?\\s-*\\\\?\\(\\(?:['\"][^'\"]+['\"]\\|\\sw\\)+\\)"
sh-escaped-line-re "\\(\n\\)"))

it works here.

HTH

Andreas

--
https://code.launchpad.net/s-x-emacs-werkstatt/
http://bazaar.launchpad.net/~a-roehler/python-mode/python-mode.el/

[Lennart Borgman]

I have some trouble understanding those regexp. What are the proper
syntax for sh heredoc?

I have some support for it in MuMaMo and just noticed that the example
Andreas mentioned did not work as I expected.

[Andreas Röhler]

Hi Lennart,

seems you got me. :-)
Thanks.
Preceding whitespaces resp. tabs are permitted by "-" in "<<-", so it's not possible to exclude it.

Well, the only clean solution I see is based on a check if "<<" is inside

a command like $(( 4 << 2 ))

BTW, how it's called in english?

Beside of writing such a check and include it into sh-script.el
a quick and dirty solution might be

(setq sh-here-doc-open-re (concat "<<-?\\s-" sh-here-document-word))

Then only customized `sh-here-document-word' will be
accepted with some whitespace before, nothing else.

Works here...

[Stefan Monnier]

> when I'm writing something like this in bash script value=$(( 4 << 2 )),
> Emacs keep thinking it's the beginning of here-document and will colorize in
> yellow all the code below this expression.

Ever heard of M-x report-emacs-bug?

Stefan

[Thomas Gambier]

Hi,

Andreas Röhler wrote:
>
> seems you got me. :-)
> Thanks.
> Preceding whitespaces resp. tabs are permitted by "-" in "<<-", so it's not possible to exclude it.
>
> Well, the only clean solution I see is based on a check if "<<" is inside
>
> a command like $(( 4 << 2 ))
>
> BTW, how it's called in english?
>
> Beside of writing such a check and include it into sh-script.el
> a quick and dirty solution might be
>
> (setq sh-here-doc-open-re (concat "<<-?\\s-" sh-here-document-word))
>
> Then only customized `sh-here-document-word' will be
> accepted with some whitespace before, nothing else.
>
> Works here...
>
>
>

It worked here except I had to change the variable name
"sh-here-document-word" because it was used as the word to insert after
typing <<. I will use this for now.

Thanks a lot.

You're right, I've just send a bug report using this function.

So I'm happy with Andreas' solution and hopefully it will be corrected
in next version of sh-script.el

Regards.

Thomas.