org.apache.lucene.queryParser.precedence
Class PrecedenceQueryParser

java.lang.Object
  extended by org.apache.lucene.queryParser.precedence.PrecedenceQueryParser
All Implemented Interfaces:
PrecedenceQueryParserConstants

public class PrecedenceQueryParser
extends Object
implements PrecedenceQueryParserConstants

Experimental query parser variant designed to handle operator precedence in a more sensible fashion than QueryParser. There are still some open issues with this parser. The following tests are currently failing in TestPrecedenceQueryParser and are disabled to make this test pass:

This class is generated by JavaCC. The only method that clients should need to call is parse(String). The syntax for query strings is as follows: A Query is a series of clauses. A clause may be prefixed by: A clause may be either: Thus, in BNF, the query grammar is:
   Query  ::= ( Clause )*
   Clause ::= ["+", "-"] [<TERM> ":"] ( <TERM> | "(" Query ")" )
 

Examples of appropriately formatted queries can be found in the query syntax documentation.


Field Summary
static org.apache.lucene.queryParser.precedence.PrecedenceQueryParser.Operator AND_OPERATOR
           
 Token jj_nt
           
 boolean lookingAhead
           
static org.apache.lucene.queryParser.precedence.PrecedenceQueryParser.Operator OR_OPERATOR
           
 Token token
           
 PrecedenceQueryParserTokenManager token_source
           
 
Fields inherited from interface org.apache.lucene.queryParser.precedence.PrecedenceQueryParserConstants
_ESCAPED_CHAR, _NUM_CHAR, _TERM_CHAR, _TERM_START_CHAR, _WHITESPACE, AND, Boost, CARAT, COLON, DEFAULT, EOF, FUZZY_SLOP, LPAREN, MINUS, NOT, NUMBER, OR, PLUS, PREFIXTERM, QUOTED, RangeEx, RANGEEX_END, RANGEEX_GOOP, RANGEEX_QUOTED, RANGEEX_START, RANGEEX_TO, RangeIn, RANGEIN_END, RANGEIN_GOOP, RANGEIN_QUOTED, RANGEIN_START, RANGEIN_TO, RPAREN, TERM, tokenImage, WILDTERM
 
Constructor Summary
PrecedenceQueryParser(CharStream stream)
           
PrecedenceQueryParser(PrecedenceQueryParserTokenManager tm)
           
PrecedenceQueryParser(String f, Analyzer a)
          Constructs a query parser.
 
Method Summary
protected  void addClause(List clauses, int conj, int modifier, Query q)
           
protected  void addClause(Vector clauses, int conj, int modifier, Query q)
          Deprecated. use addClause(List, int, int, Query) instead.
 Query andExpression(String field)
           
 Query Clause(String field)
           
 int Conjunction()
           
 void disable_tracing()
           
 void enable_tracing()
           
static String escape(String s)
          Returns a String where those characters that QueryParser expects to be escaped are escaped by a preceding \.
 ParseException generateParseException()
           
 Analyzer getAnalyzer()
           
protected  Query getBooleanQuery(List clauses)
          Factory method for generating query, given a set of clauses.
protected  Query getBooleanQuery(List clauses, boolean disableCoord)
          Factory method for generating query, given a set of clauses.
protected  Query getBooleanQuery(Vector clauses)
          Deprecated. use getBooleanQuery(List) instead
protected  Query getBooleanQuery(Vector clauses, boolean disableCoord)
          Deprecated. use getBooleanQuery(List, boolean) instead
 org.apache.lucene.queryParser.precedence.PrecedenceQueryParser.Operator getDefaultOperator()
          Gets implicit operator setting, which will be either AND_OPERATOR or OR_OPERATOR.
 String getField()
           
protected  Query getFieldQuery(String field, String queryText)
           
protected  Query getFieldQuery(String field, String queryText, int slop)
          Base implementation delegates to getFieldQuery(String,String).
 float getFuzzyMinSim()
          Get the minimal similarity for fuzzy queries.
 int getFuzzyPrefixLength()
          Get the prefix length for fuzzy queries.
protected  Query getFuzzyQuery(String field, String termStr, float minSimilarity)
          Factory method for generating a query (similar to getWildcardQuery(java.lang.String, java.lang.String)).
 Locale getLocale()
          Returns current locale, allowing access by subclasses.
 boolean getLowercaseExpandedTerms()
           
 Token getNextToken()
           
 int getPhraseSlop()
          Gets the default slop for phrases.
protected  Query getPrefixQuery(String field, String termStr)
          Factory method for generating a query (similar to getWildcardQuery(java.lang.String, java.lang.String)).
protected  Query getRangeQuery(String field, String part1, String part2, boolean inclusive)
           
 Token getToken(int index)
           
protected  Query getWildcardQuery(String field, String termStr)
          Factory method for generating a query.
static void main(String[] args)
          Command line tool to test QueryParser, using SimpleAnalyzer.
 int Modifier()
           
 Query parse(String expression)
          Parses a query string, returning a Query.
 Query Query(String field)
           
 void ReInit(CharStream stream)
           
 void ReInit(PrecedenceQueryParserTokenManager tm)
           
 void setDefaultOperator(org.apache.lucene.queryParser.precedence.PrecedenceQueryParser.Operator op)
          Sets the boolean operator of the QueryParser.
 void setFuzzyMinSim(float fuzzyMinSim)
          Set the minimum similarity for fuzzy queries.
 void setFuzzyPrefixLength(int fuzzyPrefixLength)
          Set the prefix length for fuzzy queries.
 void setLocale(Locale locale)
          Set locale used by date range parsing.
 void setLowercaseExpandedTerms(boolean lowercaseExpandedTerms)
          Whether terms of wildcard, prefix, fuzzy and range queries are to be automatically lower-cased or not.
 void setPhraseSlop(int phraseSlop)
          Sets the default slop for phrases.
 Query Term(String field)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

AND_OPERATOR

public static final org.apache.lucene.queryParser.precedence.PrecedenceQueryParser.Operator AND_OPERATOR

OR_OPERATOR

public static final org.apache.lucene.queryParser.precedence.PrecedenceQueryParser.Operator OR_OPERATOR

token_source

public PrecedenceQueryParserTokenManager token_source

token

public Token token

jj_nt

public Token jj_nt

lookingAhead

public boolean lookingAhead
Constructor Detail

PrecedenceQueryParser

public PrecedenceQueryParser(String f,
                             Analyzer a)
Constructs a query parser.

Parameters:
f - the default field for query terms.
a - used to find terms in the query text.

PrecedenceQueryParser

public PrecedenceQueryParser(CharStream stream)

PrecedenceQueryParser

public PrecedenceQueryParser(PrecedenceQueryParserTokenManager tm)
Method Detail

parse

public Query parse(String expression)
            throws ParseException
Parses a query string, returning a Query.

Parameters:
expression - the query string to be parsed.
Throws:
ParseException - if the parsing fails

getAnalyzer

public Analyzer getAnalyzer()
Returns:
Returns the analyzer.

getField

public String getField()
Returns:
Returns the field.

getFuzzyMinSim

public float getFuzzyMinSim()
Get the minimal similarity for fuzzy queries.


setFuzzyMinSim

public void setFuzzyMinSim(float fuzzyMinSim)
Set the minimum similarity for fuzzy queries. Default is 0.5f.


getFuzzyPrefixLength

public int getFuzzyPrefixLength()
Get the prefix length for fuzzy queries.

Returns:
Returns the fuzzyPrefixLength.

setFuzzyPrefixLength

public void setFuzzyPrefixLength(int fuzzyPrefixLength)
Set the prefix length for fuzzy queries. Default is 0.

Parameters:
fuzzyPrefixLength - The fuzzyPrefixLength to set.

setPhraseSlop

public void setPhraseSlop(int phraseSlop)
Sets the default slop for phrases. If zero, then exact phrase matches are required. Default value is zero.


getPhraseSlop

public int getPhraseSlop()
Gets the default slop for phrases.


setDefaultOperator

public void setDefaultOperator(org.apache.lucene.queryParser.precedence.PrecedenceQueryParser.Operator op)
Sets the boolean operator of the QueryParser. In default mode (OR_OPERATOR) terms without any modifiers are considered optional: for example capital of Hungary is equal to capital OR of OR Hungary.
In AND_OPERATOR mode terms are considered to be in conjuction: the above mentioned query is parsed as capital AND of AND Hungary


getDefaultOperator

public org.apache.lucene.queryParser.precedence.PrecedenceQueryParser.Operator getDefaultOperator()
Gets implicit operator setting, which will be either AND_OPERATOR or OR_OPERATOR.


setLowercaseExpandedTerms

public void setLowercaseExpandedTerms(boolean lowercaseExpandedTerms)
Whether terms of wildcard, prefix, fuzzy and range queries are to be automatically lower-cased or not. Default is true.


getLowercaseExpandedTerms

public boolean getLowercaseExpandedTerms()
See Also:
setLowercaseExpandedTerms(boolean)

setLocale

public void setLocale(Locale locale)
Set locale used by date range parsing.


getLocale

public Locale getLocale()
Returns current locale, allowing access by subclasses.


addClause

protected void addClause(Vector clauses,
                         int conj,
                         int modifier,
                         Query q)
Deprecated. use addClause(List, int, int, Query) instead.


addClause

protected void addClause(List clauses,
                         int conj,
                         int modifier,
                         Query q)

getFieldQuery

protected Query getFieldQuery(String field,
                              String queryText)
                       throws ParseException
Throws:
ParseException - throw in overridden method to disallow

getFieldQuery

protected Query getFieldQuery(String field,
                              String queryText,
                              int slop)
                       throws ParseException
Base implementation delegates to getFieldQuery(String,String). This method may be overridden, for example, to return a SpanNearQuery instead of a PhraseQuery.

Throws:
ParseException - throw in overridden method to disallow

getRangeQuery

protected Query getRangeQuery(String field,
                              String part1,
                              String part2,
                              boolean inclusive)
                       throws ParseException
Throws:
ParseException - throw in overridden method to disallow

getBooleanQuery

protected Query getBooleanQuery(Vector clauses)
                         throws ParseException
Deprecated. use getBooleanQuery(List) instead

Factory method for generating query, given a set of clauses. By default creates a boolean query composed of clauses passed in. Can be overridden by extending classes, to modify query being returned.

Parameters:
clauses - List that contains BooleanClause instances to join.
Returns:
Resulting Query object.
Throws:
ParseException - throw in overridden method to disallow

getBooleanQuery

protected Query getBooleanQuery(List clauses)
                         throws ParseException
Factory method for generating query, given a set of clauses. By default creates a boolean query composed of clauses passed in. Can be overridden by extending classes, to modify query being returned.

Parameters:
clauses - List that contains BooleanClause instances to join.
Returns:
Resulting Query object.
Throws:
ParseException - throw in overridden method to disallow

getBooleanQuery

protected Query getBooleanQuery(Vector clauses,
                                boolean disableCoord)
                         throws ParseException
Deprecated. use getBooleanQuery(List, boolean) instead

Factory method for generating query, given a set of clauses. By default creates a boolean query composed of clauses passed in. Can be overridden by extending classes, to modify query being returned.

Parameters:
clauses - List that contains BooleanClause instances to join.
disableCoord - true if coord scoring should be disabled.
Returns:
Resulting Query object.
Throws:
ParseException - throw in overridden method to disallow

getBooleanQuery

protected Query getBooleanQuery(List clauses,
                                boolean disableCoord)
                         throws ParseException
Factory method for generating query, given a set of clauses. By default creates a boolean query composed of clauses passed in. Can be overridden by extending classes, to modify query being returned.

Parameters:
clauses - List that contains BooleanClause instances to join.
disableCoord - true if coord scoring should be disabled.
Returns:
Resulting Query object.
Throws:
ParseException - throw in overridden method to disallow

getWildcardQuery

protected Query getWildcardQuery(String field,
                                 String termStr)
                          throws ParseException
Factory method for generating a query. Called when parser parses an input term token that contains one or more wildcard characters (? and *), but is not a prefix term token (one that has just a single * character at the end)

Depending on settings, prefix term may be lower-cased automatically. It will not go through the default Analyzer, however, since normal Analyzers are unlikely to work properly with wildcard templates.

Can be overridden by extending classes, to provide custom handling for wildcard queries, which may be necessary due to missing analyzer calls.

Parameters:
field - Name of the field query will use.
termStr - Term token that contains one or more wild card characters (? or *), but is not simple prefix term
Returns:
Resulting Query built for the term
Throws:
ParseException - throw in overridden method to disallow

getPrefixQuery

protected Query getPrefixQuery(String field,
                               String termStr)
                        throws ParseException
Factory method for generating a query (similar to getWildcardQuery(java.lang.String, java.lang.String)). Called when parser parses an input term token that uses prefix notation; that is, contains a single '*' wildcard character as its last character. Since this is a special case of generic wildcard term, and such a query can be optimized easily, this usually results in a different query object.

Depending on settings, a prefix term may be lower-cased automatically. It will not go through the default Analyzer, however, since normal Analyzers are unlikely to work properly with wildcard templates.

Can be overridden by extending classes, to provide custom handling for wild card queries, which may be necessary due to missing analyzer calls.

Parameters:
field - Name of the field query will use.
termStr - Term token to use for building term for the query (without trailing '*' character!)
Returns:
Resulting Query built for the term
Throws:
ParseException - throw in overridden method to disallow

getFuzzyQuery

protected Query getFuzzyQuery(String field,
                              String termStr,
                              float minSimilarity)
                       throws ParseException
Factory method for generating a query (similar to getWildcardQuery(java.lang.String, java.lang.String)). Called when parser parses an input term token that has the fuzzy suffix (~) appended.

Parameters:
field - Name of the field query will use.
termStr - Term token to use for building term for the query
Returns:
Resulting Query built for the term
Throws:
ParseException - throw in overridden method to disallow

escape

public static String escape(String s)
Returns a String where those characters that QueryParser expects to be escaped are escaped by a preceding \.


main

public static void main(String[] args)
                 throws Exception
Command line tool to test QueryParser, using SimpleAnalyzer. Usage:
java org.apache.lucene.queryParser.QueryParser <input>

Throws:
Exception

Conjunction

public final int Conjunction()
                      throws ParseException
Throws:
ParseException

Modifier

public final int Modifier()
                   throws ParseException
Throws:
ParseException

Query

public final Query Query(String field)
                  throws ParseException
Throws:
ParseException

andExpression

public final Query andExpression(String field)
                          throws ParseException
Throws:
ParseException

Clause

public final Query Clause(String field)
                   throws ParseException
Throws:
ParseException

Term

public final Query Term(String field)
                 throws ParseException
Throws:
ParseException

ReInit

public void ReInit(CharStream stream)

ReInit

public void ReInit(PrecedenceQueryParserTokenManager tm)

getNextToken

public final Token getNextToken()

getToken

public final Token getToken(int index)

generateParseException

public ParseException generateParseException()

enable_tracing

public final void enable_tracing()

disable_tracing

public final void disable_tracing()


Copyright © 2000-2010 Apache Software Foundation. All Rights Reserved.