Utilizing Regexp (or something else) to replace an arbitrary string length of the same character with the same string length of another character.

Utilizing Regexp (or something else) to replace an arbitrary string length of the same character with the same string length of another character.

[Tim Visher]

Hello Everyone,

I have a bunch of arbitrarily long strings of '=' characters and I
would like to replace them one for one with '-' characters.  I know I
could do this with a simple find and replace using isearch, but that
would require me going through them one at a time.  I'm wondering if
there's a way to do this with a regex such as:

    r/(=+)/-{length of n}

Obviously that's a major bastardization of syntax and doesn't really
exist in any language, but I figure this should be able to be done in
Emacs somehow.

Thanks in advance!

-- 

In Christ,

Timmy V.

http://burningones.com/
http://five.sentenc.es/ - Spend less time on e-mail

Re: Utilizing Regexp (or something else) to replace an arbitrary string length of the same character with the same string length of another character.

[Peter Dyballa]

Am 26.11.2008 um 15:41 schrieb Tim Visher:

> I have a bunch of arbitrarily long strings of '=' characters and I
> would like to replace them one for one with '-' characters.

Have you thought of replace-string? (replace-string from-string to- 
string &optional delimited start end) does not use a regular  
expression, it substitutes one string (=) with another (-).

>
> In Christ,


No! In Emacs.

--
Greetings

   Pete

We are usually convinced more easily by reasons we have found  
ourselves than by those which have occurred to others.
				– Blaise Pascal

Re: Utilizing Regexp (or something else) to replace an arbitrary string length of the same character with the same string length of another character.

[Xah Lee]

On Nov 26, 6:41 am, "Tim Visher" <tim.vis...@gmail.com> wrote:
> Hello Everyone,
>
> I have a bunch of arbitrarily long strings of '=' characters and I
> would like to replace them one for one with '-' characters.  I know I
> could do this with a simple find and replace using isearch, but that
> would require me going through them one at a time.  I'm wondering if
> there's a way to do this with a regex such as:
>
>     r/(=+)/-{length of n}
>
> Obviously that's a major bastardization of syntax and doesn't really
> exist in any language, but I figure this should be able to be done in
> Emacs somehow.

if your question is about interactive use, then you can use

query-replace
query-replace-regexp

after you type the find string and replace string, you can just type
“!” to replace them all in one shot in the current buffer.

If you don't want it to promp you on the first finding, you can call
replace-string instead.

If your question is about doing the replacement on whole directory of
files, you can mark the files in dired and then invoke dired-do-query-
replace-regexp.

See:

• Find and Replace with Emacs
  http://xahlee.org/emacs/emacs_find_replace.html

• Interactively Find and Replace String Patterns on Multiple Files
  http://xahlee.org/emacs/find_replace_inter.html

If your question is about writing a lisp program so that you can press
a button to do all the replacement you want without needing to answer
prompt bout find/replace string, on a single file or bunch of files,
it's very easy too. See for example:

• Elisp Lesson: Repeated Find Replace
  http://xahlee.org/emacs/elisp_repeat_replace.html

> In Christ,

• Has Religion Made Useful Contributions to Civilization?
  http://xahlee.org/p/religion_Russell.html

  Xah
∑ http://xahlee.org/

☄

Re: Utilizing Regexp (or something else) to replace an arbitrary string length of the same character with the same string length of another character.

[Tim Visher]

Yeah, I did consider using replace-string and query-replace-string and
their ilk.  The issue is that I use the characters I want to replace
at other locations where I don't want them replaced.  Also, I want to
replace an arbitrary amount of them at one time.  I actually already
did the edits that I want done by using query-replace-string.
However, if the document had been much longer, that really would've
taken too long.  It doesn't sound like there's a quick way to do this
in Emacs.  Oh well.

Thanks anyway.

On Wed, Nov 26, 2008 at 12:25 PM, Xah Lee <xahlee@gmail.com> wrote:
> On Nov 26, 6:41 am, "Tim Visher" <tim.vis...@gmail.com> wrote:
>> Hello Everyone,
>>
>> I have a bunch of arbitrarily long strings of '=' characters and I
>> would like to replace them one for one with '-' characters.  I know I
>> could do this with a simple find and replace using isearch, but that
>> would require me going through them one at a time.  I'm wondering if
>> there's a way to do this with a regex such as:
>>
>>     r/(=+)/-{length of n}
>>
>> Obviously that's a major bastardization of syntax and doesn't really
>> exist in any language, but I figure this should be able to be done in
>> Emacs somehow.
>
> if your question is about interactive use, then you can use
>
> query-replace
> query-replace-regexp
>
> after you type the find string and replace string, you can just type
> "!" to replace them all in one shot in the current buffer.
>
> If you don't want it to promp you on the first finding, you can call
> replace-string instead.
>
> If your question is about doing the replacement on whole directory of
> files, you can mark the files in dired and then invoke dired-do-query-
> replace-regexp.
>
> See:
>
> • Find and Replace with Emacs
>  http://xahlee.org/emacs/emacs_find_replace.html
>
> • Interactively Find and Replace String Patterns on Multiple Files
>  http://xahlee.org/emacs/find_replace_inter.html
>
> If your question is about writing a lisp program so that you can press
> a button to do all the replacement you want without needing to answer
> prompt bout find/replace string, on a single file or bunch of files,
> it's very easy too. See for example:
>
> • Elisp Lesson: Repeated Find Replace
>  http://xahlee.org/emacs/elisp_repeat_replace.html
>
>> In Christ,
>
> • Has Religion Made Useful Contributions to Civilization?
>  http://xahlee.org/p/religion_Russell.html
>
>  Xah
> ∑ http://xahlee.org/
>
> ☄
>



-- 

In Christ,

Timmy V.

http://burningones.com/
http://five.sentenc.es/ - Spend less time on e-mail

Re: Utilizing Regexp (or something else) to replace an arbitrary string length of the same character with the same string length of another character.

[Peter Dyballa]

Am 27.11.2008 um 21:24 schrieb Tim Visher:

> The issue is that I use the characters I want to replace
> at other locations where I don't want them replaced.

You can mark a region. This will restrict substitutions to happen  
only inside the marked region.

--
Greetings

   Pete

Remember: use logout to logout.

Re: Utilizing Regexp (or something else) to replace an arbitrary string length of the same character with the same string length of another character.

[Andreas Politz]

Peter Dyballa wrote:
> 
> Am 27.11.2008 um 21:24 schrieb Tim Visher:
> 
>> The issue is that I use the characters I want to replace
>> at other locations where I don't want them replaced.
> 
> You can mark a region. This will restrict substitutions to happen only 
> inside the marked region.
> 
> -- 
> Greetings
> 
>   Pete
> 
> Remember: use logout to logout.
> 
> 
> 
> 
I guess this regexp will never match

\(.\)\1*\=\1*

Maybe this will:

(defun replace-chars-around-point (new-char)
   "Replace all occurences of char at, before and after point with
NEW-CHAR."
   (interactive (list
		(read-char
		 (format "Replace %s with: "
			 (thing-at-point 'char)))))
   (let ((p (point))		    ;save-excursion does not work here
	(char (thing-at-point 'char)))
     (if (not char)
	(error "Buffer is empty"))
     (skip-chars-backward char)
     (re-search-forward (format "%s+" char))
     (replace-match (make-string (- (match-end 0)
				   (match-beginning 0)) new-char))
     (goto-char p)))


-ap

Re: Utilizing Regexp (or something else) to replace an arbitrary string length of the same character with the same string length of another character.

[tyler]

"Tim Visher" <tim.visher@gmail.com> writes:

> Yeah, I did consider using replace-string and query-replace-string and
> their ilk.  The issue is that I use the characters I want to replace
> at other locations where I don't want them replaced.  Also, I want to
> replace an arbitrary amount of them at one time.  I actually already
> did the edits that I want done by using query-replace-string.
> However, if the document had been much longer, that really would've
> taken too long.  It doesn't sound like there's a quick way to do this
> in Emacs.  Oh well.
>

This brings to mind the old chestnut:

  Some people, when confronted with a problem, think "I know, I’ll use
  regular expressions." Now they have two problems. --Jamie Zawinski

Evaluate the following (C-x C-e with point after the final ')' ), then
call it with `M-x switcheroo' when point is before the sample text below.
It solves your problem, as I understand it. 


(defun switcheroo ()
  "Replaces multiple consecutive '=' chars with the same number of '*'.
Single '=' are left unmolested"
  (interactive)
  (save-excursion
    (while (search-forward "=")
      (if (looking-at "=")
	  (progn (backward-char 1)
		 (while (looking-at "=")
		   (delete-char 1)
		   (insert "*")))))))

  
==========asdf;lkj asdf= asdflkj = asdf
asflkj ==asdfa;lkj 
aslkj ===as;fl;kj =====asd;flkj 
as;dlfkja sd=============
asdf=asdflkj=asdfas=

=asdf=asdf=
==========================


HTH,

Tyler

-- 
There is something fascinating about science. One gets such wholesale 
returns of conjecture out of such a trifling investment of fact.
                                       --Mark Twain