In article <mailman.18090.1358877053.855.help-gnu-emacs@gnu.org>,
 Peter Dyballa <Peter_Dyballa@Web.DE> wrote:

> Am 22.01.2013 um 17:44 schrieb Barry Margolin:
> 
> > Since it's 
> > immediately followed by .*, which matches anything, the regexp will 
> > match whether or not the line begins with whitespace.
> 
> Yes, it not only matches the beginning of every line, it also matches the 
> beginning of every empty lineŠ

That's not an issue, because the regexp includes ":". So it only matches 
on lines that contain a colon.

But there's no difference between:

^[ \t]*.*:

and:

^.*:

There *would* be a difference if you used grouping, e.g.:

^\([ \t]*\)\(.*\):

because this allows you to extract the whitespace prefix and the part of 
the line after it.

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