Re: Emacs: adding 1 to every number made of 2 digits inside a marked region.

[Hongyi Zhao <hongyi.zhao@gmail.com>]

On Thu, Sep 23, 2021 at 6:08 PM Stephen Berman <stephen.berman@gmx.net> wrote:
>
> On Thu, 23 Sep 2021 17:00:01 +0800 Hongyi Zhao <hongyi.zhao@gmail.com> wrote:
>
> > On Thu, Sep 23, 2021 at 4:07 PM Stephen Berman <stephen.berman@gmx.net> wrote:
> [...]
> >> In your first screenshot it looks like point in *scratch* is after the
> >> number 30 when you evaluate the while-sexp.  Make sure point is before
> >> 34 and then it should work.
> >
> > Exactly. Thank you for pointing this out. Then I do the following
> > testing in the scratch buffer:
> >
> > some    30
> > word    31 *
> >
> > *  This is the position of point.
> >
> > M-:
> > (while (re-search-backward "[[:digit:]]\\{2\\}" nil t) (let ((x
> >  (match-string 0))) (delete-backward-char 2) (insert (format "%d" (1+
> >  (string-to-number x))))))
> >
> > Then I obtained the following in scratch:
> >
> > ;; This buffer is for
> > tex100999897969594939291908988878685848382818079787776757473727170696867666564636261605958575655545352515049484746454443424140393837363534333231
> >
> > Any hints for this strange result?
>
> Since you're now searching backwards, you need to delete forwards to
> retain the position of the numbers and you need to make sure point is in
> front of the number that was just incremented before continuing the loop:
>
> (while (re-search-backward "[[:digit:]]\\{2\\}" nil t)
>   (let ((x (match-string 0))
>         (pt (point)))
>     (delete-char 2)
>     (insert (format "%d" (1+ (string-to-number x))))
>     (goto-char pt)))

Tried but it does nothing.

HZ