lib/DX/Hypothesis.pm

   1 package DX::Hypothesis;
   2
   3 use DX::ActionPolicy::LockScope;
   4 use Types::Standard qw(ArrayRef);
   5 use DX::Utils qw(deparse);
   6 use DX::Class;
   7
   8 has scope => (is => 'ro', isa => Scope, required => 1);
   9
  10 has resolved_propositions => (
  11   is => 'ro', isa => ResolvedPropositionSet, required => 1
  12 );
  13
  14 has outstanding_propositions => (
  15   is => 'ro', isa => ArrayRef[Proposition], required => 1
  16 );
  17
  18 has actions => (
  19   is => 'ro', isa => ArrayRef[Action], required => 1
  20 );
  21
  22 has action_policy => (is => 'ro', isa => ActionPolicy, required => 1);
  23
  24 sub head_proposition { shift->outstanding_propositions->[0] }
  25
  26 sub with_actions {
  27   my ($self, @actions) = @_;
  28   my $hyp = $self;
  29   foreach my $act (@actions) {
  30     return undef unless $self->action_policy->allows($act);
  31     ($hyp, my @events) = $act->dry_run($hyp);
  32     return undef unless $hyp;
  33     $hyp = $hyp->but_recheck_for(@events);
  34     return undef unless $hyp;
  35   }
  36   return $hyp;
  37 }
  38
  39 sub but_recheck_for {
  40   my ($self, @events) = @_;
  41   my ($still_resolved, @recheck) = $self->resolved_propositions
  42                                         ->but_expire_for(@events);
  43   return $self unless @recheck;
  44
  45   my $ap = DX::ActionPolicy::LockScope->new(
  46     lock_to_depth => $self->scope->depth,
  47     next_policy => $self->action_policy,
  48   );
  49
  50   # we should probably be doing something about pruning the scope
  51   # but that's completely pointless until we have rules
  52
  53   my $hyp = ref($self)->new(
  54     scope => $self->scope,
  55     resolved_propositions => DX::ResolvedPropositionSet->new_empty,
  56     outstanding_propositions => \@recheck,
  57     actions => [],
  58     action_policy => $ap,
  59   );
  60
  61   my $ss = DX::SearchState->new_for($hyp);
  62
  63   return undef unless my $sol_ss = $ss->find_solution;
  64
  65   my $sol_rps = $sol_ss->current_hypothesis->resolved_propositions;
  66
  67   my $rps = $still_resolved;
  68
  69   $rps = $rps->with_updated_dependencies_for(
  70     $_, $sol_rps->dependencies_for($_)
  71   ) for @recheck;
  72
  73   return $self->but(resolved_propositions => $rps);
  74 }
  75
  76 sub resolve_head_dependent_on {
  77   my ($self, $depends) = @_;
  78   my ($first, @rest) = @{$self->outstanding_propositions};
  79   $self->but(
  80     resolved_propositions => $self->resolved_propositions
  81                                   ->with_resolution_for(
  82                                       $first,
  83                                       $depends,
  84                                     ),
  85     outstanding_propositions => \@rest,
  86   );
  87 }
  88
  89 1;