What is wrong with this regexp search?

What is wrong with this regexp search?

[Mirko]

Hello,

I am trying to write a command that will convert all occurance of a
lower case character followed by an uppercase character (such as kA)
into a sequance of lowercase characters separated by an underscore.
So, kA would go to k_a

This is my attempt:

(defun camel-to-underline ()
  (interactive)
  (while (re-search-forward "[a-z][A-Z]")
    (insert "_")
    (downcase-region (point) (+ 1 (point))) ) )

The problem is that re-search-forward seems to capture the very next
character, irrespective whether the following one is uppercase or
lowercase.

What am I missing?

Thanks,

Mirko

Re: What is wrong with this regexp search?

[rgb]

> The problem is that re-search-forward seems to capture the very next
> character, irrespective whether the following one is uppercase or
> lowercase.

case-fold-search is probably non-nil
Put a let someplace around your search.
Then it doesn't matter if it's on or off.

(let (case-fold-search)(re-search-forward "[a-z][A-Z]"))

Re: What is wrong with this regexp search?

[Juanma Barranquero]

On 10 Nov 2006 08:24:53 -0800, Mirko <mvukovic@nycap.rr.com> wrote:

> This is my attempt:
>
> (defun camel-to-underline ()
>   (interactive)
>   (while (re-search-forward "[a-z][A-Z]")
>     (insert "_")
>     (downcase-region (point) (+ 1 (point))) ) )
>
> The problem is that re-search-forward seems to capture the very next
> character, irrespective whether the following one is uppercase or
> lowercase.
>
> What am I missing?

The variable `case-fold-search', I think.

Try with:

 (defun camel-to-underline ()
  (interactive)
  (let (case-fold-search)
   (while (re-search-forward "[a-z][A-Z]")
       (insert "_")
           (downcase-region (point) (+ 1 (point))))))

                    /L/e/k/t/u

Re: What is wrong with this regexp search?

[Mirko]

Juanma Barranquero wrote:
> On 10 Nov 2006 08:24:53 -0800, Mirko <mvukovic@nycap.rr.com> wrote:
>
> > This is my attempt:
> >
> > (defun camel-to-underline ()
> >   (interactive)
> >   (while (re-search-forward "[a-z][A-Z]")
> >     (insert "_")
> >     (downcase-region (point) (+ 1 (point))) ) )
> >
> > The problem is that re-search-forward seems to capture the very next
> > character, irrespective whether the following one is uppercase or
> > lowercase.
> >
> > What am I missing?
>
> The variable `case-fold-search', I think.
>
> Try with:
>
>  (defun camel-to-underline ()
>   (interactive)
>   (let (case-fold-search)
>    (while (re-search-forward "[a-z][A-Z]")
>        (insert "_")
>            (downcase-region (point) (+ 1 (point))))))
>
>                     /L/e/k/t/u

Thank you to both of you.  That was indeed the problem.

Mirko