$$ perl -MYAPE::Regex::Explain -e'die YAPE::Regex::Explain->new(qr/((.
+)\2*)/i)->explain'
The regular expression:
(?i-msx:((.)\2*))
matches as follows:
NODE EXPLANATION
----------------------------------------------------------------------
(?i-msx: group, but do not capture (case-insensitive)
(with ^ and $ matching normally) (with . not
matching \n) (matching whitespace and #
normally):
----------------------------------------------------------------------
( group and capture to \1:
----------------------------------------------------------------------
( group and capture to \2:
----------------------------------------------------------------------
. any character except \n
----------------------------------------------------------------------
) end of \2
----------------------------------------------------------------------
\2* what was matched by capture \2 (0 or
more times (matching the most amount
possible))
----------------------------------------------------------------------
) end of \1
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
