lib/DX/Step/Backtrack.pm

   1 package DX::Step::Backtrack;
   2
   3 use DX::Class;
   4
   5 with 'DX::Role::Step';
   6
   7 sub apply_to {
   8   my ($self, $ss) = @_;
   9   trace backtrack => [ statement => [ [ symbol => 'backtrack' ] ] ];
  10   foreach my $adj (@{$ss->decisions_taken}) {
  11     my ($rspace_was, $ss_was) = @$adj;
  12     return $ss_was->but(
  13       next_step => $rspace_was->remaining_resolution_space->next_step
  14     );
  15   }
  16   return $ss->but(next_step => $ss->on_exhaustion_step);
  17 }
  18
  19 1;