regexp/emacs selective replace

regexp/emacs selective replace

[m121212]

Hi, 

I have a tricky problem that I'm not sure how to solve.  I have a latex
document with several figure environments that look like this:

\begin{figure}
 \includegraphics{blah.ps}
\end{figure}

but need to look like this:

\begin{figure}
  \begin{center} \includegraphics{blah.ps} \end{center}
\end{figure}

Some of the figure environments already have this however, and I don't want
to end up with something like this:

\begin{figure}
  \begin{center}\begin{center} \includegraphics{blah.ps}
\end{center}\end{center}
\end{figure}

Any ideas?   Also, is there a way Emacs can just wrap any selection with
custom, predefined tags?

thanks,
m121212  
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Re: regexp/emacs selective replace

[Barry Margolin]

In article <mailman.11424.1259102060.2239.help-gnu-emacs@gnu.org>,
 m121212 <m121212@mailinator.com> wrote:

> Hi, 
> 
> I have a tricky problem that I'm not sure how to solve.  I have a latex
> document with several figure environments that look like this:
> 
> \begin{figure}
>  \includegraphics{blah.ps}
> \end{figure}
> 
> but need to look like this:
> 
> \begin{figure}
>   \begin{center} \includegraphics{blah.ps} \end{center}
> \end{figure}
> 
> Some of the figure environments already have this however, and I don't want
> to end up with something like this:
> 
> \begin{figure}
>   \begin{center}\begin{center} \includegraphics{blah.ps}
> \end{center}\end{center}
> \end{figure}
> 
> Any ideas?

Does query-replace-regexp do what you want?  It will prompt you before 
each possible replacement, and you can say whether to replace that 
instance.

-- 
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***

Re: regexp/emacs selective replace

[harven]

m121212 <m121212@mailinator.com> writes:

> Hi, 
>
> I have a tricky problem that I'm not sure how to solve.  I have a latex
> document with several figure environments that look like this:
>
> \begin{figure}
>  \includegraphics{blah.ps}
> \end{figure}
>
> but need to look like this:
>
> \begin{figure}
>   \begin{center} \includegraphics{blah.ps} \end{center}
> \end{figure}
>
> Some of the figure environments already have this however, and I don't want
> to end up with something like this:
>
> \begin{figure}
>   \begin{center}\begin{center} \includegraphics{blah.ps}
> \end{center}\end{center}
> \end{figure}
>
> Any ideas?   Also, is there a way Emacs can just wrap any selection with
> custom, predefined tags?

Anchor to the beginning and end of line.

M-x replace-regexp RET
^ *\\includegraphics{[^}]*} *$ RET
\\begin{center} \& \\end{center} RET

Re: regexp/emacs selective replace

[m121212]

Thanks for your repsonses!  The solution for me in the end was just to record
a keyboard macro.  Do you use a particular guide for regexps?  Also, could
you explain this part:  {[^}]*} *$ RET ?

M-x replace-regexp RET
^ *\\includegraphics{[^}]*} *$ RET
\\begin{center} \& \\end{center} RET


Thanks,
m121212
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Re: regexp/emacs selective replace

[Joost Kremers]

m121212 wrote:
>
> Thanks for your repsonses!  The solution for me in the end was just to record
> a keyboard macro.  Do you use a particular guide for regexps?

(info "(emacs) Regexps")

>  Also, could
> you explain this part:  {[^}]*} *$ RET ?

see the above info node. ;-) { and the final } are just literal characters,
[...] describes a set of alternatives. ^ negates such a set, so that [^}]
matches any character other than }.

note that {[^}]*} could also have been written as {.*?} (which IHMO is a bit
clearer and easier to read).


-- 
Joost Kremers                                      joostkremers@yahoo.com
Selbst in die Unterwelt dringt durch Spalten Licht
EN:SiS(9)

Re: regexp/emacs selective replace

[harven]

Joost Kremers <joostkremers@yahoo.com> writes:

> note that {[^}]*} could also have been written as {.*?} (which IHMO is a bit
> clearer and easier to read).

strictly speaking {[^}]*} is not the same as {.*?}
The first will match

{xxx
} 

because emacs regexp [^...] matches newline if it is not included in the
brackets. By the way {.*?} is probably closer to what the OP asks for.

Re: regexp/emacs selective replace

[Joost Kremers]

harven wrote:
> Joost Kremers <joostkremers@yahoo.com> writes:
>
>> note that {[^}]*} could also have been written as {.*?} (which IHMO is a bit
>> clearer and easier to read).
>
> strictly speaking {[^}]*} is not the same as {.*?}

when it comes to regexps, all that counts is "strictly speaking". ;-)

> The first will match
>
> {xxx
> } 
>
> because emacs regexp [^...] matches newline if it is not included in the
> brackets.

yup, true. forgot about that...


-- 
Joost Kremers                                      joostkremers@yahoo.com
Selbst in die Unterwelt dringt durch Spalten Licht
EN:SiS(9)

Re: regexp/emacs selective replace

[harven]

m121212 <m121212@mailinator.com> writes:

> Thanks for your repsonses!  The solution for me in the end was just to record
> a keyboard macro.  Do you use a particular guide for regexps?  Also, could
> you explain this part:  {[^}]*} *$ RET ?

  {[^}]*} *$ means

  {          first an opening brace, 
  [^}]*      then any number of characters that are not a closing brace
  }          then a closing brace,
   *         any number of spaces,
  $          and the line ends there
  RET        RETURN to proceed

  This matches {xxx} 
  but not {xxx} \end{center} because the line does not end after the brace.

See http://www.emacswiki.org/emacs/RegularExpression

Re: regexp/emacs selective replace

[Joost Kremers]

harven wrote:
>   {[^}]*} *$ means
[...]
>   This matches {xxx} 
>   but not {xxx} \end{center} because the line does not end after the brace.

and because there would be a } in the matching string.


-- 
Joost Kremers                                      joostkremers@yahoo.com
Selbst in die Unterwelt dringt durch Spalten Licht
EN:SiS(9)

Re: regexp/emacs selective replace

[Xah Lee]

On Nov 23, 5:41 am, m121212 <m121...@mailinator.com> wrote:
> Hi,
>
> I have a tricky problem that I'm not sure how to solve.  I have a latex
> document with several figure environments that look like this:
>
> \begin{figure}
>  \includegraphics{blah.ps}
> \end{figure}
>
> but need to look like this:
>
> \begin{figure}
>   \begin{center} \includegraphics{blah.ps} \end{center}
> \end{figure}
>
> Some of the figure environments already have this however, and I don't want
> to end up with something like this:
>
> \begin{figure}
>   \begin{center}\begin{center} \includegraphics{blah.ps}
> \end{center}\end{center}
> \end{figure}

This page answers your question exactly:

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

if you prefer emacs to ask you for each case, perhaps just to be sure
your regex didn't find a bad match, see:

• Lisp Lesson: Regex Replace with a Function
  http://xahlee.org/emacs/lisp_regex_replace_func.html

> Any ideas?   Also, is there a way Emacs can just wrap any selection with
> custom, predefined tags?

(defun wrap-markup ()
  "Insert a markup <b></b> around a region."
  (interactive)
    (goto-char (region-end)) (insert "</b>")
    (goto-char (region-beginning)) (insert "<b>")
)

the above is from a collection of simple elisp examples at

• Emacs Lisp Examples
  http://xahlee.org/emacs/elisp_examples.html

  Xah
∑ http://xahlee.org/

☄