org.jrdf.query.relation.operation.mem.common
Interface RelationProcessor

All Known Implementing Classes:

RelationProcessorImpl

public interface RelationProcessor

Common process engine - basically gets headings and then calls process on the process engine.

Method Summary

Relation	convertToConstants(Relation resultRelation) Converts a relation with no heading and no tuples to false (TABLE_DUM) and a relation with no heading but some tuples to true (TABLE_DEE).
Relation	processRelations(Set<Relation> relations, TupleEngine tupleEngine) A set of relations that are to be processed by the tuple engine.

Method Detail

processRelations

Relation processRelations(Set<Relation> relations,
                          TupleEngine tupleEngine)

A set of relations that are to be processed by the tuple engine. First headings are processed and then the bodies of the relations.

Parameters:

relations - the relations to be processed by the tuple engine.

tupleEngine - the engine.

Returns:

the result of calling the tuple engine with all relations given as input.

convertToConstants

Relation convertToConstants(Relation resultRelation)

Converts a relation with no heading and no tuples to false (TABLE_DUM) and a relation with no heading but some tuples to true (TABLE_DEE).

Parameters:

resultRelation - the relation to convert.

Returns:

either TABLE_DUM (false), TABLE_DEE (true) or the same relation.