Re: "C-a" the first character in each line?

[Barry Margolin <barmar@alum.mit.edu>]

In article <1182693577.251257.35950@u2g2000hsc.googlegroups.com>,
 weber <hugows@gmail.com> wrote:

> On Jun 24, 10:20 am, Nikos Apostolakis <nikos...@gmail.com> wrote:
> > Hello group,
> >
> > in the scratch buffer I did
> >
> > -----------------
> > (while (search-forward-regexp "^\\(.\\)" nil t)
> >   (replace-match "\% \1"))
> >
> > laa
> > moo
> > nii
> > -----------------
> >
> > I expected
> >
> > %
> > % laa
> > % moo
> > % nii
> >
> > but isnstead I get
> >
> > % ^A
> > % ^Aaa
> > % ^Aoo
> > % ^Aii
> >
> > where ^A stands for the character "C-a".
> >
> > What am I missing?
> >
> > TIA,
> > Nikos
> 
> Dunno why, but \\1 instead of \1 solves it.

Because \ is used as an escape prefix for both Elisp strings and regular 
expressions.  It's first processed by the Elisp string parser, which 
uses \<number> to represent characters by their ASCII code, and \\ to 
represent a literal \.  You need to use the latter to get the \ passed 
through to the regexp processor.

-- 
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
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