Sounds interesting, and though I cannot ATM think of any situation where I might want to use it, I am almost certain that I have in the past wished for something similar (if not the same). I am not sure if you meant for the last example:
# parses text like:
# name = japhy  age = "22"  lang = 'Perl'
# into a hash... but doesn't capture the quotes!
my %data = $text =~ m{
  ([^=\s]+) \s* = \s* 
  (?:
    (?3= ['"] ) (.*? ) \3 |
    ( \S+ )
  )
}xg;

[download]
So that what was previously in the (?2= .* ) would be returned.

This case might be resolved in other ways,
Sorry couldn't help presenting one: 
while ( <DATA> ) {
  my %data = $_ =~ m{
    ([^=\s]+) \s* = \s* 
    ["']?(
      (?<=')[^']* |
      (?<=")[^"]* |
      \S+
    )["']?
  }xg;

[download]

-enlil

(as a side note I would have to agree with demerphq that named captures would be cool as well)

In reply to Re: Regex Report by Enlil
in thread Regex Report by japhy

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.