I am a bit confused on some aspects of Emacs regexps. Specifically with the paragraph on this page
- ‘
\W
’ matches a character which is not within a word- ‘
\B
’ matches characters which are not a word boundary- ‘
\`
’ matches the beginning of the whole input- ‘
\'
’ matches the end of the whole input
Can someone give examples of where each of these might apply?
Also suppose for a generic regexp R, if I augment it as ^
R$
what does that mean? Does it mean it matches the expression at the beginning and end of sentences. Elsewhere on this site I have seen the regexp ^\s-$
being used to detect blank lines.
I understand each of ^
and $
in isolation but not when used together