# Copyright (c) 2023 Yuki Kimoto
# MIT License
class Comparator : interface_t {
  version_from SPVM;
   
  use Comparable;
   
  required method : int ($x1 : object, $x2 : object);
   
  # Class Methods
  static method default_comparator : Comparator () {
     
    my $default_comparator = method : int ($object1 : Comparable, $object2 : Comparable) {
       
      my $cmp = 0;
      if ($object1 && $object2) {
         
        $cmp = $object1->cmp($object1, $object2);
      }
      elsif ($object1) {
        $cmp = 1;
      }
      elsif ($object2 ) {
        $cmp = -1;
      }
       
      return $cmp;
    };
     
    return $default_comparator;
  }
   
}