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, $then) = @_;
62 my $bound = $var->with_value($value);
64 by_id => { %{$self->by_id}, $var->id => $bound },
69 sub bind_stream_then {
70 my ($self, $var, $stream, $then) = @_;
71 my $bound = $var->with_stream($stream);
73 by_id => { %{$self->by_id}, $var->id => $bound },
75 )->mark_choice($bound);
79 my ($self, $var) = @_;
80 $self->but(last_choice => [ $self, $var ]);
85 my ($state, $var) = ($self);
86 while (($state, $var) = @{$state->last_choice}) {
87 $var->bound_value; $var->clear_bound_value;
88 return $state->mark_choice($var) unless $var->bound_stream->is_exhausted;
90 $self->return_from_run(undef);
94 my ($self, $then) = @_;
95 $self->but(next_op => $then);
99 my (undef, $return) = @_;
100 (our $Run_Return)->($return);
104 my (undef, $return) = @_;
105 if (our $Op_Return) {
106 $Op_Return->($return);
114 local our $Run_Return = $return;
115 while (my $op = $state->next_op) {
116 my $backtrack = with_return {
118 local our $Op_Return = $return;
119 $state = $op->run($state);
122 if ($backtrack) { $state = $state->backtrack }
129 $_[0]->then(DX::Op::Backtrack->new);
133 my ($self, @but) = @_;
134 $self->new(%$self, @but);
137 sub pop_return_stack {
139 my @stack = @{$self->return_stack};
140 my $top = pop @stack;
141 $self->but(return_stack => \@stack, next_op => $top->[0]);
144 sub push_return_then {
145 my ($self, $return, $then) = @_;
147 return_stack => [ @{$self->return_stack}, [ $return, $self ] ],