Re: [AUCTeX] Entering maths

[Mosè Giordano]

Hi Denis,

2017-06-13 12:51 GMT+02:00 Denis Bitouzé <address@hidden>:
> Hi,
>
> does AUCTeX provide something making life easier for inline-math
> expressions (`|' standing for the cursor position):
>
> - `\(|\)',
> - `$|$' (OK, it's easy to type two dollar signs and go back to write the
>   expression between the dollar signs, but would be better if done by
>   a shortcut)?

Yes, of course ;-)  You have to customize the `TeX-electric-math'
option 
(https://www.gnu.org/software/auctex/manual/auctex.html#index-TeX_002delectric_002dmath):


 -- User Option: TeX-electric-math
     If the variable is non-nil and you type '$' outside math mode,
     AUCTeX will automatically insert the opening and closing symbols
     for an inline equation and put the point between them.  The opening
     symbol will blink when 'blink-matching-paren' is non-nil.  If
     'TeX-electric-math' is nil, typing '$' simply inserts '$' at point,
     this is the default.

     Besides 'nil', possible values for this variable are '(cons "$"
     "$")' for TeX inline equations '$...$', and '(cons "\\(" "\\)")'
     for LaTeX inline equations '\(...\)'.

     If the variable is non-nil and point is inside math mode right
     between a couple of single dollars, pressing '$' will insert
     another pair of dollar signs and leave the point between them.
     Thus, if 'TeX-electric-math' is set to '(cons "$" "$")' you can
     easily obtain a TeX display equation '$$...$$' by pressing '$'
     twice in a row.  (Note that you should not use double dollar signs
     in LaTeX because this practice can lead to wrong spacing in typeset
     documents.)

     In addition, when the variable is non-nil and there is an active
     region outside math mode, typing '$' will put around the active
     region symbols for opening and closing inline equation and keep the
     region active, leaving point after the closing symbol.  By pressing
     repeatedly '$' while the region is active you can toggle between an
     inline equation, a display equation, and no equation.  To be
     precise, '$...$' is replaced by '$$...$$', whereas '\(...\)' is
     replaced by '\[...\]'.

   If you want to automatically insert '$...$' in plain TeX files, and
'\(...\)' in LaTeX files by pressing '$', add the following to your init
file
     (add-hook 'plain-TeX-mode-hook
           (lambda () (set (make-variable-buffer-local 'TeX-electric-math)
                   (cons "$" "$"))))
     (add-hook 'LaTeX-mode-hook
           (lambda () (set (make-variable-buffer-local 'TeX-electric-math)
                   (cons "\\(" "\\)"))))


> In the same vein, I know constructing display-math expressions with
> `\[...\]':
>
> - has some drawbacks if `amsmath' is not loaded,

I believe this is fixed if you have a recent LaTeX version (2015/01/01
or newer, which is in TeX Live 2016).

> - is synonym to `\begin{equation*}...\end{equation*}' if `amsmath' is
>   loaded,
>
> but does AUCTeX provide something for `\[|\]'?

If you set `LaTeX-electric-left-right-brace'
(https://www.gnu.org/software/auctex/manual/auctex.html#index-LaTeX_002delectric_002dleft_002dright_002dbrace)
to non nil, as you as you type "\[", the closing "\]" is inserted
after point.

Bye,
Mosè