lib/DX/Step/ResolveProposition.pm

   1 package DX::Step::ResolveProposition;
   2
   3 use DX::Step::EnterRecheck;
   4 use DX::Step::CompleteResolution;
   5 use DX::Step::Backtrack;
   6
   7 use DX::Utils qw(expand_deps);
   8
   9 use DX::Class;
  10
  11 with 'DX::Role::Step';
  12
  13 has resolution_space => (is => 'ro', isa => ResolutionSpace);
  14
  15 sub resolves { shift->resolution_space->proposition }
  16
  17 sub current_resolution { shift->resolution_space->next_resolution }
  18
  19 sub actions { shift->current_resolution->actions }
  20
  21 sub depends_on { shift->current_resolution->veracity_depends_on }
  22
  23 sub but_first {
  24   my ($self, @actions) = @_;
  25   $self->but(actions => [ @actions, @{$self->actions} ]);
  26 }
  27
  28 sub but_with_dependencies_on {
  29   my ($self, @deps) = @_;
  30   $self->but(depends_on => [ @{$self->depends_on}, @deps ]);
  31 }
  32
  33 sub apply_to {
  34   my ($self, $old_ss) = @_;
  35   trace resolve => [ statement => [
  36     [ symbol => 'resolve' ],
  37     [ block => [
  38       [ statement => [
  39         [ symbol => 'proposition' ],
  40         @{$self->resolves->for_deparse->[1]},
  41       ] ],
  42       (@{$self->actions}
  43         ? [ statement => [
  44             [ symbol => 'actions' ],
  45             [ block => $self->actions ],
  46           ] ]
  47         : ()),
  48       [ statement => [
  49         [ symbol => 'depends_on' ],
  50         [ block => [
  51           map [ statement => [
  52             [ symbol => (split '::', ${$_->[0]})[-1] ],
  53             [ value_path => [ @{$_}[1..$#$_] ] ]
  54           ] ], @{$self->depends_on}
  55         ] ],
  56       ] ],
  57     ] ]
  58   ] ];
  59   my $rspace = $self->resolution_space;
  60   my $ss = $old_ss->but(
  61     next_step => DX::Step::CompleteResolution->new(
  62       original_search_state => $old_ss,
  63       resolution_space => $rspace,
  64     )
  65   );
  66   my $old_hyp = $old_ss->current_hypothesis;
  67   (my $hyp, my @recheck) = $old_hyp->with_resolution(
  68     $self->resolves, $self->depends_on, $self->actions
  69   );
  70   return $ss->but(next_step => DX::Step::Backtrack->new) unless $hyp;
  71   return $ss->but(current_hypothesis => $hyp) unless @recheck;
  72   return $ss->but(
  73     current_hypothesis => $hyp,
  74     next_step => DX::Step::EnterRecheck->new(
  75       proposition_list => \@recheck,
  76       on_completion_step => $ss->next_step,
  77       on_failure_step => $rspace->remaining_resolution_space->next_step,
  78     ),
  79   );
  80 }
  81
  82 1;