#! perl -slw
use strict;

our $N ||= 3;

my $word = $ARGV[0] or die "No search term";

my $text = do{ local $/; <DATA> };

my $re_word = qr[
    (?<=\s)
    $word
    [[:punct:]]*
    (?=\s)
]x;

$text =~ s[
    (
        (?: \S+ \s+ ){0,$N}
        $re_word
        (?: .{0,60} $re_word )?
        (?= ( (?: \s+ \S+ ){0,$N} )  )
    )
][
    my $extract = "...$1$2...";
    $extract =~ s[ ( \s ) ( $word ) ( [[:punct:]]*\s ) ][$1<<$2>>$3]gx;
    print $extract, $/;
]gsex;

__END__
Regular expressions have always been a weak spot for me, and I've got a
question that's got me stumped. Here's the problem I'm trying to solve.
I have somwhat large articles of text (returned from a search), what I'd
like to do is capture the word and X number of words before and after it
while tagging the matching word in the captured text. My inital thought
was to try something like this. The problem I have is that if there is
more than one term and they overlap, the nth term will not be annotated.
So my next thought is lookahead/lookbehind, but they don't capture.
Is there a way to do this with a single regex? Is a regex even the best
way to do this? Thanks, -Lee