# make a table of regular expression patterns
my %table = ( qr/(\d+)/      => 'INT',
              qr/([A-Z]\w*)/ => 'ID',
              .... # more tokens here );
my ($parser) = shift;

my $s = $parser->YYData->{INPUT};

my @matches; # any matches found by our re go in here

foreach my $re ( keys %table ) {
        # for each regexp, check to see if it matches, and
        # put all the captured values in @matches if it does
        @matches = ( $$s =~ m/\G$re/gc );

       # return the appropriate token, and captures...
        return( $table{$re}, @matches) if (@matches);
} # end search for a token match

# token not found... put error handling here ...