no.sesat.search.query.parser
Class DefaultOperatorClauseImpl

java.lang.Object
  no.sesat.search.query.parser.AbstractClause
      no.sesat.search.query.parser.AbstractUnaryClause
          no.sesat.search.query.parser.AbstractBinaryClause
              no.sesat.search.query.parser.DefaultOperatorClauseImpl

All Implemented Interfaces:

Serializable, no.sesat.commons.visitor.Visitable, BinaryClause, Clause, DefaultOperatorClause, UnaryClause

public class DefaultOperatorClauseImpl
extends AbstractBinaryClause
implements DefaultOperatorClause

The OrClauseImpl represents a joining clause between two terms in the query. For example: "term1 OR term2". Objects of this class are immutable

Version:

$Id: OrClauseImpl.java 2399 2006-03-01 21:01:02Z mickw $

See Also:

Serialized Form

Field Summary

Fields inherited from class no.sesat.search.query.parser.AbstractUnaryClause

firstClause

Fields inherited from class no.sesat.search.query.parser.AbstractClause

DFAULT_REFERENCE_MAP_TYPE, ERR_FAILED_FINDING_OR_USING_CONSTRUCTOR, ERR_MUST_ALWAYS_USE_ARGED_CONSTRUCTOR

Constructor Summary

protected

DefaultOperatorClauseImpl(String term, Clause first, Clause second, Set<TokenPredicate> knownPredicates, Set<TokenPredicate> possiblePredicates) Create the OrClauseImpl with the given term, left and right child clauses, and known and possible predicate sets.

Method Summary

static DefaultOperatorClauseImpl

createDefaultOperatorClause(Clause first, Clause second, TokenEvaluationEngine engine) Creator method for OrClauseImpl objects.

Methods inherited from class no.sesat.search.query.parser.AbstractBinaryClause

getSecondClause, toString

Methods inherited from class no.sesat.search.query.parser.AbstractUnaryClause

createClause, getFirstClause

Methods inherited from class no.sesat.search.query.parser.AbstractClause

accept, addClauseInUse, findClauseInUse, findPredicates, getKnownPredicates, getPossiblePredicates, getTerm, hashCode

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface no.sesat.search.query.BinaryClause

getSecondClause

Methods inherited from interface no.sesat.search.query.UnaryClause

getFirstClause

Methods inherited from interface no.sesat.search.query.Clause

getKnownPredicates, getPossiblePredicates, getTerm

Methods inherited from interface no.sesat.commons.visitor.Visitable

accept

Constructor Detail

DefaultOperatorClauseImpl

protected DefaultOperatorClauseImpl(String term,
                                    Clause first,
                                    Clause second,
                                    Set<TokenPredicate> knownPredicates,
                                    Set<TokenPredicate> possiblePredicates)

Create the OrClauseImpl with the given term, left and right child clauses, and known and possible predicate sets.

Parameters:

term - the term for this OrClauseImpl.

knownPredicates - set of known predicates.

possiblePredicates - set of possible predicates.

first - the left child clause.

second - the right child clause.

Method Detail

createDefaultOperatorClause

public static DefaultOperatorClauseImpl createDefaultOperatorClause(Clause first,
                                                                    Clause second,
                                                                    TokenEvaluationEngine engine)

Creator method for OrClauseImpl objects. By avoiding the constructors, and assuming all OrClauseImpl objects are immutable, we can keep track (via a weak reference map) of instances already in use in this JVM and reuse them. The methods also allow a chunk of creation logic for the OrClauseImpl to be moved out of the QueryParserImpl.jj file to here.

Parameters:

first - the left child clause of the operation clause we are about to create (or find).

second - the right child clause of the operation clause we are about to create (or find).

engine - the factory handing out evaluators against TokenPredicates. Also holds state information about the current term/clause we are finding predicates against.

Returns:

returns a OrCOrClauseImplstance matching the term, left and right child clauses. May be either newly created or reused.