Re: [Bug-AUCTeX] 11.87; Failure to insert smart quotes in some circumstances

[Mosè Giordano]

Hi Ralf,

2014/1/11 Ralf Angeli <address@hidden>:
> * Mosč Giordano (2014-01-11) writes:
>
>> thanks for your report.  The problem is in the `texmathp' function,
>> and in particular in the regexp used for searching math togglers, ie
>> `texmathp-toggle-regexp'.  Its value is
>> "\\([^\\\\\\$]\\|\\`\\)\\(\\$\\$\\|\\$\\)", but this doesn't match a
>> dollar preceded by two escapes.
>> "\\(\\\\\\\\\\|[^\\\\\\$]\\|\\`\\)\\(\\$\\$\\|\\$\\)" should do the
>> trick, but I'd like a confirmation by someone more experienced in
>> regexps than me.  Actually we should make sure there is an even number
>> of escapes, not just two, then perhaps something like `TeX-escaped-p'
>> might be needed.
>
> IIRC we used something like "[^\\]\\(\\\\\\\\\\)*" to check if something
> is unescaped before we had `TeX-escaped-p'.  Let's assume the logic for
> the regexp is the following:
>
> match a pair of dollar signs or a single dollar sign under the condition
> that a) in front of it there is no dollar sign or escape or b) if there
> is a dollar sign in front if it, it is preceded by an odd number of
> escapes or c) if there is an escape in front of it, it has to be
> preceded by an odd number of escapes, so that there is an even number of
> escapes in a row or d) the dollar sign(s) occur(s) at the start of the
> buffer
>
> In that case the regexp could look like this:
>
> "\\([^\\$]\\|[^\\]\\(\\\\\\\\\\)*\\\\\\$\\|[^\\]\\(\\\\\\\\\\)+\\|\\`\\)\\(\\$\\$\\|\\$\\)"
>

Thanks for your suggestions!  Unfortunately, this regexp doesn't match
the opening dollar in
    \\$something$

> Note: I think that the "[^\\\\\\$]" in the original regexp has too many
> escapes.  "[^\\$]" should suffice because you don't need to escape the
> characters in a character alternative.
>

I think you're right, `re-builder' confirms your idea.

> The regexp would become rather complicated, so it might be worth to
> check if using `TeX-escaped-p' is the nicer alternative.  Or somebody
> has an idea how to simplify the regexp.
>

The attached patch uses the same logic of `TeX-escaped-p', but fails
to recognize the math mode in
    \$$something$
because finds `$$' preceded by an escape.  All in all, a single well
conceived regexp probably is better.

Bye,
Mosè

texmathp.el.patch
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