Package org.apache.lucene.sandbox.search
Class TermAutomatonQuery
- java.lang.Object
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- org.apache.lucene.search.Query
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- org.apache.lucene.sandbox.search.TermAutomatonQuery
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- All Implemented Interfaces:
Accountable
public class TermAutomatonQuery extends Query implements Accountable
A proximity query that lets you express an automaton, whose transitions are terms, to match documents. This is a generalization of other proximity queries likePhraseQuery,MultiPhraseQueryandSpanNearQuery. It is likely slow, since it visits any document having any of the terms (i.e. it acts like a disjunction, not a conjunction likePhraseQuery), and then it must merge-sort all positions within each document to test whether/how many times the automaton matches.After creating the query, use
createState(),setAccept(int, boolean),addTransition(int, int, java.lang.String)andaddAnyTransition(int, int)to build up the automaton. Once you are done, callfinish()and then execute the query.This code is very new and likely has exciting bugs!
- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Field Summary
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Fields inherited from interface org.apache.lucene.util.Accountable
NULL_ACCOUNTABLE
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Constructor Summary
Constructors Constructor Description TermAutomatonQuery(String field)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description voidaddAnyTransition(int source, int dest)Adds a transition matching any term.voidaddTransition(int source, int dest, String term)Adds a transition to the automaton.voidaddTransition(int source, int dest, BytesRef term)Adds a transition to the automaton.intcreateState()Returns a new state; state 0 is always the initial state.WeightcreateWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)booleanequals(Object other)Returns true iffois equal to this.voidfinish()Call this once you are done adding states/transitions.voidfinish(int determinizeWorkLimit)Call this once you are done adding states/transitions.inthashCode()longramBytesUsed()Queryrewrite(IndexSearcher indexSearcher)voidsetAccept(int state, boolean accept)Marks the specified state as accept or not.StringtoDot()Returns the dot (graphviz) representation of this automaton.StringtoString(String field)voidvisit(QueryVisitor visitor)-
Methods inherited from class org.apache.lucene.search.Query
classHash, rewrite, sameClassAs, toString
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.apache.lucene.util.Accountable
getChildResources
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Constructor Detail
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TermAutomatonQuery
public TermAutomatonQuery(String field)
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Method Detail
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createState
public int createState()
Returns a new state; state 0 is always the initial state.
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setAccept
public void setAccept(int state, boolean accept)Marks the specified state as accept or not.
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addTransition
public void addTransition(int source, int dest, String term)Adds a transition to the automaton.
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addTransition
public void addTransition(int source, int dest, BytesRef term)Adds a transition to the automaton.
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addAnyTransition
public void addAnyTransition(int source, int dest)Adds a transition matching any term.
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finish
public void finish()
Call this once you are done adding states/transitions.
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finish
public void finish(int determinizeWorkLimit)
Call this once you are done adding states/transitions.- Parameters:
determinizeWorkLimit- Maximum effort to spend determinizing the automaton. Higher numbers allow this operation to consume more memory but allow more complex automatons. UseOperations.DEFAULT_DETERMINIZE_WORK_LIMITas a decent default if you don't otherwise know what to specify.
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createWeight
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException
- Overrides:
createWeightin classQuery- Throws:
IOException
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equals
public boolean equals(Object other)
Returns true iffois equal to this.
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ramBytesUsed
public long ramBytesUsed()
- Specified by:
ramBytesUsedin interfaceAccountable
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toDot
public String toDot()
Returns the dot (graphviz) representation of this automaton. This is extremely useful for visualizing the automaton.
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rewrite
public Query rewrite(IndexSearcher indexSearcher) throws IOException
- Overrides:
rewritein classQuery- Throws:
IOException
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visit
public void visit(QueryVisitor visitor)
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