word => 'id'

##</code><code>##

word => [qw{id1 id2}]

##</code><code>##

...
$words2ids{fc $text} = $token;
...
s/$re/++$found{fc $1}, "$1 $words2ids{fc $1}"/eg;
...

##</code><code>##

...
push @{$words2ids{fc $text}}, $token;
...
s/$re/++$found{fc $1}, "$1 @{$words2ids{fc $1}}"/eg;
...