Regarding the length $^N > 1 test, I added that because while refining this RE I discovered that it was capable of considering a single-character string to be palindromic (new word?), since "a" in reverse is still "a".

Update: Now that I think about it, the length $^N > 1 test is better written as ..+ earlier in the RE, like this: 

qr/(..+)
   (??{
       ( lc $^N eq reverse lc $^N )
       ? '' : '(?!)'
   })
/ix

[download]

...thus forcing at least two characters to be tested in the first place, rather than hand-coding a test for two or more characters via 'length'. Duh!


Dave

In reply to Re^4: regex at word boundary by davido
in thread regex at word boundary by mikeraz

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.