Not a working solution, just a thought experiment:

Perl 6 has a regex construct spelled <*abcd>. It is a shortcut for a|ab|abc|abcd (also note that in Perl 6 regexes, the longest pipe-delimited alternative wins, not the first one as in Perl 5).

Sadly no compiler implements the <*abcd> feature yet, so I can't demonstrate it, but I think something like this should work: 

my token longest_asc_desc {
    # ascending
    | <*0123456789> ** <?after 9>
    | <*1234567890> ** <?after 0>
    | <*2345678901> ** <?after 1>
    ...
    # descending:
    | <*9876543210> ** <?after 0>
    | <*8765432109> ** <?after 9>
    | <*7654321098> ** <?after 8>
    ...
}

[download]
Perl 6 - second systems done right

In reply to Re: Find Length Of Longest Ascending/Descending Sequence by moritz
in thread Find Length Of Longest Ascending/Descending Sequence by Limbic~Region

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.