it.unimi.di.mg4j.query.nodes
Class MultiIndexTermExpander

java.lang.Object
  it.unimi.di.mg4j.query.nodes.AbstractTermExpander
      it.unimi.di.mg4j.query.nodes.MultiIndexTermExpander

All Implemented Interfaces:

QueryTransformer

public class MultiIndexTermExpander
extends AbstractTermExpander

A term expander that replaces every term or prefix with a disjunction of queries; each query is made by the same term or prefix preceded by a selection over a different index.

Nested Class Summary

protected class

MultiIndexTermExpander.ExpanderVisitor

Field Summary

String[]	index The list of index names that will be used to expand the term.
int	n A copy of the length of index.

Constructor Summary

MultiIndexTermExpander(String... index)
Creates a new multi-index term expander.

Method Summary

protected Query	expand(Consecutive consecutive)
protected Query	expand(OrderedAnd orderedAnd)
Query	expand(Prefix prefix) Expands a prefix.
Query	expand(Term term) Expands a single term.
protected MultiIndexTermExpander.ExpanderVisitor	expanderVisitor() Returns a new expander visitor.

Methods inherited from class it.unimi.di.mg4j.query.nodes.AbstractTermExpander

transform

Methods inherited from class java.lang.Object

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

Field Detail

index

public final String[] index

The list of index names that will be used to expand the term.

n

public final int n

A copy of the length of index.

Constructor Detail

MultiIndexTermExpander

public MultiIndexTermExpander(String... index)

Creates a new multi-index term expander.

Parameters:

index - a list of index names that will be used to expand the term.

Method Detail

expanderVisitor

protected MultiIndexTermExpander.ExpanderVisitor expanderVisitor()

Description copied from class: AbstractTermExpander

Returns a new expander visitor.

Overrides:

expanderVisitor in class AbstractTermExpander

Returns:

a visitor performing the expansion.

expand

protected Query expand(Consecutive consecutive)

expand

protected Query expand(OrderedAnd orderedAnd)

expand

public Query expand(Term term)

Description copied from class: AbstractTermExpander

Expands a single term.

Specified by:

expand in class AbstractTermExpander

Parameters:

term - a term to be expanded.

Returns:

the resulting query.

expand

public Query expand(Prefix prefix)

Description copied from class: AbstractTermExpander

Expands a prefix.

Specified by:

expand in class AbstractTermExpander

Parameters:

prefix - the prefix to be expanded.

Returns:

the resulting query.