Package org.apache.drill.common.logical.data.visitors

Interface LogicalVisitor<RETURN,EXTRA,EXCEP extends Throwable>

Type Parameters:
RETURN - The class associated with the return of each visit method.
EXTRA - The class object associated with additional data required for a particular operator modification.
EXCEP - An optional exception class that can be thrown when a portion of a modification or traversal fails. Must extend Throwable. In the case where the visitor does not throw any caught exception, this can be set as RuntimeException.
All Known Implementing Classes:
AbstractLogicalVisitor, ScanFieldDeterminer
public interface LogicalVisitor<RETURN,EXTRA,EXCEP extends Throwable>
Visitor class designed to traversal of a operator tree. Basis for a number of operator manipulations including fragmentation and materialization.