Re: count matches in string, not region?

[Tassilo Horn]

Another way would be

  (string-match-p "^[[:digit:]]\\{13\\}$" isbn)

which returns non-nil iff isbn is a string of exactly thirteen digits.

Bye,
Tassilo

Am Mi, 26. Feb 2020, um 07:24, schrieb Emanuel Berg via Users list for the GNU 
Emacs text editor:
> > Anyway as you see the 4th line doesn't look
> > good, instead of moving the point one would
> > like to invoke the/a count function with the
> > already-fetched isbn-as argument.
> >
> > So is there a count-matches-in-string or
> > something to that extent anywhere, that you
> > are aware of?
> 
> Problem solved with `replace-regexp-in-string'.
> 
> Can still be useful to count matches in
> a string, I guess...
> 
> Yank it in a temporary buffer and then use
> region there is perhaps a poor man's solution...
> 
> (defun check-isbn-at-point ()
>   "Compute and echo the check digit from the ISBN at point."
>   (interactive)
>   (let*((isbn-string (thing-at-point 'symbol t))
>         (digits-only (replace-regexp-in-string "[^0-9]" "" isbn-string))
>         (num-digits  (length digits-only))
>         (check-digit (if (> num-digits 10)
>                          (checksum-isbn-13 digits-only)
>                        (checksum-isbn-10 digits-only) )))
>     (message "check digit: %s" check-digit)
>     ))
> (defalias 'ciap #'check-isbn-at-point)
> 
> -- 
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> http://user.it.uu.se/~embe8573
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> 
> 
> 
>