package DX::SearchState;
-use Types::Standard qw(Maybe);
-use DX::Step::InvokeNextPredicate;
+use Types::Standard qw(Maybe Bool);
+use DX::Step::Backtrack;
+use DX::Step::ConsiderProposition;
+use DX::Step::MarkAsSolution;
use DX::Class;
has current_hypothesis => (is => 'ro', isa => Hypothesis, required => 1);
-has next_step => (is => 'ro', isa => Maybe[Step]);
+has next_step => (is => 'ro', isa => Maybe[Step], required => 1);
has propositions => (is => 'ro', isa => PropositionSequence, required => 1);
-has alternatives => (is => 'ro', isa => AlternativeList, required => 1);
+has adjustments_made => (is => 'ro', isa => AdjustmentList, required => 1);
+
+has is_solution_state => (is => 'ro', isa => Bool, required => 1);
+
+has on_exhaustion_step => (is => 'ro', isa => Maybe[Step], required => 1);
+
+has on_solution_step => (is => 'ro', isa => Maybe[Step], required => 1);
sub next_proposition {
- my ($self, $hyp) = @_;
- $hyp ||= $self->current_hypothesis;
+ my ($self) = @_;
+ my $hyp = $self->current_hypothesis;
$self->propositions->members->[
- $hyp->resolved_propositions->resolved_count
+ $hyp->resolved_propositions->resolved_count + 1
];
}
my ($class, $hyp, $props) = @_;
$class->new(
current_hypothesis => $hyp,
- alternatives => [],
- next_step => DX::Step::InvokeNextPredicate->new(
- proposition => $props->members->[0],
- ),
+ adjustments_made => [],
propositions => $props,
+ (@{$props->members}
+ ? (
+ next_step => DX::Step::ConsiderProposition->new(
+ proposition => $props->members->[0],
+ ),
+ is_solution_state => 0,
+ )
+ : ( next_step => undef, is_solution_state => 1 )
+ ),
+ on_exhaustion_step => undef,
+ on_solution_step => DX::Step::MarkAsSolution->new,
);
}
sub with_one_step {
my ($self) = @_;
- my $hyp = $self->current_hypothesis;
return undef unless my $step = $self->next_step;
- my ($new_ss, $alt_step) = $step->apply_to($self);
- if ($new_ss) {
- return $new_ss->but(
- alternatives => [
- ($alt_step
- ? [ $hyp, $alt_step ]
- : ()),
- @{$new_ss->alternatives}
- ],
- );
- }
- if ($alt_step) {
- return $self->but(next_step => $alt_step);
- }
- my ($first_alt, @rest_alt) = @{$self->alternatives};
- return undef unless $first_alt;
- trace 'search.backtrack.rewind_to' => $first_alt->[1];
- return $self->but(
- current_hypothesis => $first_alt->[0],
- alternatives => \@rest_alt,
- next_step => $first_alt->[1],
- );
+ #trace step => $step;
+ return $step->apply_to($self);
}
sub force_backtrack {
my ($self) = @_;
- my ($first_alt, @rest_alt) = @{$self->alternatives};
- return undef unless $first_alt;
- trace 'search.backtrack.forced' => $first_alt->[0];
- return ref($self)->new(
- current_hypothesis => $first_alt->[0],
- next_step => $first_alt->[1],
- alternatives => \@rest_alt,
- propositions => $self->propositions,
- );
+ return $self->but(
+ next_step => DX::Step::Backtrack->new,
+ )->with_one_step;
}
1;