Don't use my variables declared outside the regex pattern from within (?{}).

The problem you are having is that one of the patterns matches, then gets added to @list1, then gets unmatched by backtracking. But you never remove it from @list1 on backtracking. A simple example of this:

>perl -le"'abc1def2' =~ /(?:([a-z])(?{ print $^N }))+2/" a b c b c c d e f

The solution is to use $^R.

use strict; use warnings; my @vocabulary = qw( a abc abcd abd bc ); my $sentence = 'abdaabc'; my ($pattern) = map qr/$_/, join '|', map quotemeta, sort { length($b) <=> length($a) } # optional @vocabulary; use re 'eval'; local our @list; $sentence =~ / (?{ [] }) ^ (?: ($pattern) (?{ [ @{$^R}, $^N ] }) )+ $ (?{ @list = @{$^R} }) /x or die("No solution\n"); print( join('-', @list), "\n" ); # abd-a-abc

Without the sort, you'd get abd-a-a-bc. If you want all possible solutions:

... use re 'eval'; local our @list; $sentence =~ / (?{ [] }) ^ (?: ($pattern) (?{ [ @{$^R}, $^N ] }) )+ $ (?{ push @list, join('-', @{$^R}) }) (?!) /x; die("No solution\n") if !@list; print("$_\n") for @list;
abd-a-a-bc abd-a-abc

In reply to Re: Split a sentence into words by ikegami
in thread Split a sentence into words by ThreeMonks

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, 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, 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.