I'm too lazy to work out a complete solution but a clean approach would be to deparse the regex-compilation:

> perl -e 'use re 'debug';/(?i-xsm:(?<mon>\w+)\s+(?<day>\d+)\s+)/' 
Compiling REx "(?i-xsm:(?<mon>\w+)\s+(?<day>\d+)\s+)"
Final program:
   1: OPEN1 'mon' (3)
   3:   PLUS (5)
   4:     ALNUM (0)
   5: CLOSE1 'mon' (7)
   7: PLUS (9)
   8:   SPACE (0)
   9: OPEN2 'day' (11)
  11:   PLUS (13)
  12:     DIGIT (0)
  13: CLOSE2 'day' (15)
  15: PLUS (17)
  16:   SPACE (0)
  17: END (0)
stclass ALNUM plus minlen 4 
Freeing REx: "(?i-xsm:(?<mon>\w+)\s+(?<day>\d+)\s+)"

[download]

Now fetching all /OPEN\d+ '(\w+)'/-opcodes shouldn't be too difficult.

See perldoc re for more options.

Cheers Rolf

UPDATE: shrank example.

In reply to Re: How do I extract named variable names from regex string by LanX
in thread How do I extract named variable names from regex string by maspsr

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.