3 use Return::MultiLevel qw(with_return);
5 use Scalar::Util qw(blessed);
8 has next_op => (is => 'ro', required => 1);
10 has return_stack => (is => 'ro', required => 1);
12 has by_id => (is => 'ro', required => 1);
14 has scope => (is => 'ro', required => 1);
16 has last_choice => (is => 'ro', required => 1);
18 has id_gen => (is => 'ro', default => sub { {} });
20 has rule_set => (is => 'ro');
22 has facts => (is => 'ro');
25 my ($self, $name) = @_;
26 $self->by_id->{$self->scope->{$name}};
30 my ($self, $name, $var, $id_gen) = @_;
31 my $id = join('_', $name, ++($id_gen->{$name}||='000'));
32 DX::Var->new(id => $id, %$var);
36 my ($self, %vars) = @_;
37 my %by_id = %{$self->by_id};
38 my %id_gen = %{$self->id_gen};
39 foreach my $name (keys %vars) {
40 unless (blessed($vars{$name})) {
41 my $var = $vars{$name} = $self->allocate_var(
42 $name, $vars{$name}, \%id_gen
44 $by_id{$var->id} = $var;
48 by_id => \%by_id, id_gen => \%id_gen,
53 my ($self, %vars) = @_;
54 my ($state, %expanded) = $self->expand_vars(%vars);
56 scope => { %{$self->scope}, map +($_ => $expanded{$_}->id), keys %expanded }
61 my ($self, $var, $value) = @_;
62 my $bound = $var->with_value($value);
64 by_id => { %{$self->by_id}, $var->id => $bound },
68 sub bind_stream_then {
69 my ($self, $var, $stream, $then) = @_;
70 my $bound = $var->with_stream($stream);
72 by_id => { %{$self->by_id}, $var->id => $bound },
74 )->mark_choice($bound);
78 my ($self, $var) = @_;
79 $self->but(last_choice => [ $self, $var ]);
84 my ($state, $var) = ($self);
85 while (($state, $var) = @{$state->last_choice}) {
86 $var->bound_value; $var->clear_bound_value;
87 return $state->mark_choice($var) unless $var->bound_stream->is_exhausted;
89 $self->return_from_run(undef);
93 my ($self, $then) = @_;
94 $self->but(next_op => $then);
98 my (undef, $return) = @_;
99 (our $Run_Return)->($return);
103 my (undef, $return) = @_;
104 if (our $Op_Return) {
105 $Op_Return->($return);
113 local our $Run_Return = $return;
114 while (my $op = $state->next_op) {
115 my $backtrack = with_return {
117 local our $Op_Return = $return;
118 $state = $op->run($state);
121 if ($backtrack) { $state = $state->backtrack }
128 $_[0]->then(DX::Op::Backtrack->new);
132 my ($self, @but) = @_;
133 $self->new(%$self, @but);
136 sub pop_return_stack {
138 my @stack = @{$self->return_stack};
139 my $top = pop @stack;
140 $self->but(return_stack => \@stack, next_op => $top->[0]);
143 sub push_return_then {
144 my ($self, $return, $then) = @_;
146 return_stack => [ @{$self->return_stack}, [ $return, $self ] ],