show dependencies before backtracking

[scpubgit/DX.git] / lib / DX / Step / Backtrack.pm

diff --git a/lib/DX/Step/Backtrack.pm b/lib/DX/Step/Backtrack.pm
index 9a92677..06d1986 100644 (file)
--- a/lib/DX/Step/Backtrack.pm
+++ b/lib/DX/Step/Backtrack.pm
@@ -1,16 +1,33 @@
 package DX::Step::Backtrack;
 
+use DX::DependencyMap;
+use DX::Utils qw(format_deps);
 use DX::Class;
 
 with 'DX::Role::Step';
 
-#has resolution_space => (is => 'ro', isa => ResolutionSpace, required => 1);
+has resolution_space => (is => 'ro', isa => ResolutionSpace, required => 1);
 
 sub apply_to {
   my ($self, $ss) = @_;
-  trace backtrack => [ statement => [ [ symbol => 'backtrack' ] ] ];
+  my $rspace = $self->resolution_space;
+  trace backtrack => [ statement => [
+    [ symbol => 'backtrack' ],
+    [ statement => [
+      [ symbol => 'because' ],
+      format_deps($rspace->geometry_depends_on)
+    ] ]
+  ] ];
+  my $dmap = DX::DependencyMap->new_empty
+                              ->with_dependencies_for(
+                                  backtrack => $rspace->geometry_depends_on
+                                );
+
   foreach my $adj (@{$ss->decisions_taken}) {
     my ($rspace_was, $ss_was) = @$adj;
+    $dmap = $dmap->with_dependencies_for(
+      backtrack => $rspace_was->geometry_depends_on
+    );
     next unless @{$rspace_was->remaining_resolution_space->members};
     trace rspace => [ statement => [
       [ symbol => 'remaining' ],