switch over to storing rspace+ss as decision list
[scpubgit/DX.git] / lib / DX / Step / Backtrack.pm
CommitLineData
55131db4 1package DX::Step::Backtrack;
2
3use DX::Class;
4
5with 'DX::Role::Step';
6
7sub apply_to {
8 my ($self, $ss) = @_;
5b6cab1b 9 trace backtrack => [ statement => [ [ symbol => 'backtrack' ] ] ];
1c02730b 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 );
76329453 15 }
16 return $ss->but(next_step => $ss->on_exhaustion_step);
55131db4 17}
18
191;