Possibly even better than [a-zA-Z], which makes a limiting assumption about the alphabet being used, one could use \p{Alpha}, which accepts 102159 different code points, all of which may be considered part of the alphabet of some language somewhere at some time, and none of which include numeric digits.

Instead of I+, how about using Regexp::Common's $RE{num}{roman} pattern, which will correctly match roman numerals, case insensitively. Here's the pattern it uses to do so:

(?xi)(?=[MDCLXVI])
(?:M{0,3}
  (D?C{0,3}|CD|CM)?
  (L?X{0,3}|XL|XC)?
  (V?I{0,3}|IV|IX)?)

[download]

Dave

In reply to Re^2: regular expression by davido
in thread regular expression by Mjpaddy

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.