lift some of the rspace handling into the Resolution* classes

[scpubgit/DX.git] / lib / DX / Predicate / Eq.pm

package DX::Predicate::Eq;

use DX::Utils qw(step rspace res CONTENTS_OF);
use DX::Class;

with 'DX::Role::Predicate';

sub _resolution_space_for {
  my ($self, $left, $right) = @_;

  my $deps = [ [ CONTENTS_OF ,=> $left ], [ CONTENTS_OF ,=> $right ] ];

  if ($left->equals($right)) {
    return rspace(
      geometry_depends_on => $deps,
      members => [
        res(
          actions => [],
          veracity_depends_on => $deps,
        )
      ]
    );
  }

  my @members = map {
    my ($set_this, $to_this) = @$_;
    res(
      actions => [ $set_this->action_for_set_value($to_this) ],
      veracity_depends_on => $deps,
    );
  } grep {
    $_->[0]->can_set_value
  } (
    [ $left, $right ],
    [ $right, $left ],
  );

  return rspace(
    geometry_depends_on => $deps,
    members => \@members,
  );
}

1;