org.terrier.matching.matchops

Class SynonymOp

java.lang.Object

org.terrier.matching.matchops.Operator

org.terrier.matching.matchops.MultiTermOp

org.terrier.matching.matchops.SynonymOp

All Implemented Interfaces:

Serializable, Cloneable

Direct Known Subclasses:

PrefixTermOp

public class SynonymOp
extends MultiTermOp

This combines multiple operators into a single op. It is logically equivalent to Indri's #syn() operator.

Since:

5.0

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.slf4j.Logger	logger
static String	STRING_PREFIX

Fields inherited from class org.terrier.matching.matchops.Operator

IGNORE_LOW_IDF_TERMS

Constructor Summary

Constructors

Constructor and Description
SynonymOp(Operator[] ts)
SynonymOp(String[] ts)

Method Summary

Modifier and Type	Method and Description
protected IterablePosting	createFinalPostingIterator(List<IterablePosting> postings, List<EntryStatistics> pointers)
protected EntryStatistics	mergeStatistics(EntryStatistics[] entryStats, CollectionStatistics collStats) Adjust the statistics for the #syn operator: 1.
String	toString()

Methods inherited from class org.terrier.matching.matchops.MultiTermOp

addStatistics, clone, getConstituents, getMatcher, getPostingIterator

Methods inherited from class org.terrier.matching.matchops.Operator

equals, hashCode, parse

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

STRING_PREFIX

public static final String STRING_PREFIX

See Also:

Constant Field Values

logger

protected static final org.slf4j.Logger logger

Constructor Detail

SynonymOp

public SynonymOp(Operator[] ts)

SynonymOp

public SynonymOp(String[] ts)

Method Detail

toString

public String toString()

Specified by:

toString in class Operator

mergeStatistics

protected EntryStatistics mergeStatistics(EntryStatistics[] entryStats,
                                          CollectionStatistics collStats)

Adjust the statistics for the #syn operator: 1. The total number of occurrences F is the sum of the constituent frequencies (handled by super). 2. The in-document maxTF is the maximum of the constituent maxTFs

Overrides:

mergeStatistics in class MultiTermOp

createFinalPostingIterator

protected IterablePosting createFinalPostingIterator(List<IterablePosting> postings,
                                                     List<EntryStatistics> pointers)
                                              throws IOException

Specified by:

createFinalPostingIterator in class MultiTermOp

Throws:

IOException