no.sesat.search.query.parser
Class NotClauseImpl

java.lang.Object
  no.sesat.search.query.parser.AbstractClause
      no.sesat.search.query.parser.AbstractUnaryClause
          no.sesat.search.query.parser.NotClauseImpl

All Implemented Interfaces:

Serializable, no.sesat.commons.visitor.Visitable, Clause, NotClause, UnaryClause

public final class NotClauseImpl
extends AbstractUnaryClause
implements NotClause

The NotClauseImpl represents a not clause between prefixing another term in the query. For example: "NOT term1". Objects of this class are immutable

Version:

$Id: NotClauseImpl.java 7225 2009-04-09 00:32:20Z ssmiweve $

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

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

Method Summary

static NotClauseImpl

createNotClause(Clause first, TokenEvaluationEngine engine) Creator method for NotClauseImpl objects.

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

createClause, getFirstClause, toString

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.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

NotClauseImpl

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

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

Parameters:

term - the term for this OrClause.

knownPredicates - set of known predicates.

possiblePredicates - set of possible predicates.

first - the left child clause.

second - the right child clause. NOT USED but required to utilitise the createClause method in createNotClause.

Method Detail

createNotClause

public static NotClauseImpl createNotClause(Clause first,
                                            TokenEvaluationEngine engine)

Creator method for NotClauseImpl objects. By avoiding the constructors, and assuming all NotClauseImpl 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 NotClauseImpl 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).

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 NoNotClauseImplnstance matching the term, and left child clauses. May be either newly created or reused.