This hangs

gistfile1.txt

use v6;

class RangeSet {

    has Pair @.p;

    method add (Int $from, Any $to) {
        @.p.push: $from => $to.Num;
        }

    method to_list () {
        gather {
            my Int $max = -1;
            for sort @.p -> $r {
                my $from = ($r.key, $max + 1).max.Int;
                ($from, $r.value).perl.say;
                take $from .. $r.value;
                $r.value == Inf and last;
                $max = ($max, $r.value).max.Int;
                }
            }
        }
    }

my RangeSet $rs .= new;
$rs.add(0,1);
$rs.add(3,3);
$rs.add(5,Inf);

my Int @c = $rs.to_list;
#@crange.perl.say;

for 1..9 -> $t {
    my @x = (10 * $t + 1) .. (10 * $t + 9);
    my @z = @c ?? (@x[@c]:v) !! @x;
    @z.perl.say;
    }