Beginner trouble with regexp matching

Beginner trouble with regexp matching

[Marko Vojinovic]

Hi foks! :-)

Sorry if this question is maybe too trivial, but google wasn't my friend 
today. :-(

I am editing a TeX file, and I want to search for "\begin{equation} " (with the 
blank space at the end and without quotes), and to add the newline at the end 
instead of the blank space. So the obvious way to do it appeared to be to 
perform a regexp replacing from

  \\begin{equation}

(which finishes with a space) to

  \\begin{equation}\n

However, this doesn't work --- Emacs correctly matches the first string, but 
fails to replace it with the second, with an error "Invalid use of `\' in 
replacement text".

This is my very first try to use regular expressions for search&replace, and I 
am still learning. What am I doing wrong?

TIA, :-)
Marko

Re: Beginner trouble with regexp matching

[Jai Dayal]

[-- Attachment #1: Type: text/plain, Size: 1108 bytes --]

New lines with replace-string in emacs are a little bit..... random.

M-x replace-string  then type \\begin{equation}
then, instead of typing \n, use the key stroke C-q C-j

That should enter the newline as emacs knows it.

On Sat, Oct 29, 2011 at 10:22 AM, Marko Vojinovic <vvmarko@gmail.com> wrote:

>
> Hi foks! :-)
>
> Sorry if this question is maybe too trivial, but google wasn't my friend
> today. :-(
>
> I am editing a TeX file, and I want to search for "\begin{equation} " (with
> the
> blank space at the end and without quotes), and to add the newline at the
> end
> instead of the blank space. So the obvious way to do it appeared to be to
> perform a regexp replacing from
>
>  \\begin{equation}
>
> (which finishes with a space) to
>
>  \\begin{equation}\n
>
> However, this doesn't work --- Emacs correctly matches the first string,
> but
> fails to replace it with the second, with an error "Invalid use of `\' in
> replacement text".
>
> This is my very first try to use regular expressions for search&replace,
> and I
> am still learning. What am I doing wrong?
>
> TIA, :-)
> Marko
>
>
>

[-- Attachment #2: Type: text/html, Size: 1515 bytes --]

Re: Beginner trouble with regexp matching

[Marko Vojinovic]

On Saturday 29 October 2011 15:25:36 Jai Dayal wrote:
> New lines with replace-string in emacs are a little bit..... random.
> 
> M-x replace-string  then type \\begin{equation}
> then, instead of typing \n, use the key stroke C-q C-j
> 
> That should enter the newline as emacs knows it.

Great, it works! Thanks! :-) I didn't even need to use regexp for matching, 
ordinary string replace did the job... ;-)

Btw, is there some table which tells what should I type in Emacs to put in 
such nontrivial characters (newline, carriage return, backspace, tab, etc...)?

Best, :-)
Marko

RE: Beginner trouble with regexp matching

[Drew Adams]

> is there some table which tells what should I type in 
> Emacs to put in such nontrivial characters (newline,
> carriage return, backspace, tab, etc...)?

Depends on the mode.  In some modes such chars are self-inserting.

But you can always quote to insert any character, with `C-q': See this node of
the Emacs manual: (emacs) `Inserting Text'.  (See also these nodes: `Minibuffer
Edit', `International Chars', `Indentation Commands', `Pages', `TeX Editing',
and `Init Non-ASCII'.)