NAME

       Lucy::Search::PolyQuery - Base class for composite Query objects.

SYNOPSIS

           sub walk {
               my $query = shift;
               if ( $query->isa("Lucy::Search::PolyQuery") ) {
                   if    ( $query->isa("Lucy::Search::ORQuery") )  { ... }
                   elsif ( $query->isa("Lucy::Search::ANDQuery") ) { ... }
                   elsif ( $query->isa("Lucy::Search::RequiredOptionalQuery") ) {
                       ...
                   }
                   elsif ( $query->isa("Lucy::Search::NOTQuery") ) { ... }
               }
               else { ... }
           }

DESCRIPTION

       PolyQuery serves as a shared base class for ANDQuery, ORQuery, NOTQuery, and
       RequiredOptionalQuery.  All of these classes may serve as nodes in composite Query with a
       tree structure which may be walked.

INHERITANCE

       Lucy::Search::PolyQuery isa Lucy::Search::Query isa Lucy::Object::Obj.