Euclidean / Björlund / Toussaint algorith in Perl 6

euclid.p6

#!perl6

use v6;

# From Björklund via http://cgm.cs.mcgill.ca/~godfried/publications/banff.pdf

class Euclid
{
   method build_string(Int $level, @count, @remainder )
   { 
      my @bitmap;
   
      if ($level == -1) 
      {
         push @bitmap, 0;
      }
      elsif ( $level == -2 )
      {
         push @bitmap, 1;
      }
      else
      {
         for 0 .. @count[$level] - 1 
         {
            push @bitmap, self.build_string($level-1, @count, @remainder); 
         }
         if (@remainder[$level] != 0) 
         {     
            push @bitmap, self.build_string($level-2, @count, @remainder); 
         }
      }
   
      return @bitmap;
   }
   
   
   method compute_bitmap($num_slots, $num_pulses)
   { 
   
      my @count;
      my @remainder;

      my $divisor = $num_slots - $num_pulses; 
   
      @remainder[0] = $num_pulses; 
   
      my $level = 0; 
   
      while (@remainder[$level] > 1 )
      { 
         @count[$level] = $divisor / @remainder[$level]; 
         @remainder[$level+1] = $divisor % @remainder[$level]; 
         $divisor = @remainder[$level]; 
         $level++;
      }
   
      @count[$level] = $divisor; 
      my @bits = self.build_string($level, @count, @remainder); 
      while (@bits[0] == 0)
      {
         shift @bits;
         push @bits, 0;
      }
   
      return @bits;
   } 
}

sub MAIN(Int :$slots, Int :$fills) {
   say Euclid.new.compute_bitmap($slots, $fills);
}