no.sesat.search.query.parser
Class WordClauseImpl

java.lang.Object
  no.sesat.search.query.parser.AbstractClause
      no.sesat.search.query.parser.AbstractLeafClause
          no.sesat.search.query.parser.WordClauseImpl

All Implemented Interfaces:

Serializable, no.sesat.commons.visitor.Visitable, Clause, LeafClause, WordClause

public final class WordClauseImpl
extends AbstractLeafClause
implements WordClause

Represent a word in the query. May contain the optional field (field:word). May contain both character and digits but cannot contain only digits (a IntegerClause will be used instead then).

Version:

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

See Also:

Serialized Form

Field Summary

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

field

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

WordClauseImpl(String term, String field, Set<TokenPredicate> knownPredicates, Set<TokenPredicate> possiblePredicates) Create clause with the given term, known and possible predicates.

Method Summary

static WordClauseImpl

createWordClause(String term, String field, TokenEvaluationEngine predicate2evaluatorFactory) Creator method for WordClauseImpl objects.

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

createClause, getField, 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.WordClause

getField

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

getKnownPredicates, getPossiblePredicates, getTerm

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

accept

Constructor Detail

WordClauseImpl

protected WordClauseImpl(String term,
                         String field,
                         Set<TokenPredicate> knownPredicates,
                         Set<TokenPredicate> possiblePredicates)

Create clause with the given term, known and possible predicates.

Parameters:

term - the term (query string) for this clause.

field - the field for this clause. May be null.

knownPredicates - the set of known predicates for this clause.

possiblePredicates - the set of possible predicates for this clause.

Method Detail

createWordClause

public static WordClauseImpl createWordClause(String term,
                                              String field,
                                              TokenEvaluationEngine predicate2evaluatorFactory)

Creator method for WordClauseImpl objects. By avoiding the constructors, and assuming all WordClauseImpl 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 WordClauseImpl to be moved out of the QueryParserImpl.jj file to here.

Parameters:

term - the term this clause represents.

field - any field this clause was specified against.

predicate2evaluatorFactory - the factory handing out evaluators against TokenPredicates. Also holds state information about the current term/clause we are finding predicates against.

Returns:

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