SimpleParser (MG4J 5.2)

java.lang.Object
- it.unimi.di.mg4j.query.parser.SimpleParser

All Implemented Interfaces:

QueryParser, SimpleParserConstants, FlyweightPrototype<QueryParser>
```
public class SimpleParser
extends Object
implements QueryParser, SimpleParserConstants
```
A simple parser that transform a query string into a query.
The parser supports multiple indices. You must provide a set of index aliases that the user will use to select indices, and the name of the default index alias to be used. After that, you parse a query by using the parse(String) method.
The parser generated by JavaCC for this class will break terms using operators and nonspace-to-space transitions. Operators can be included in terms, if needed, using the backslash, which acts as an escape character, and makes the next character (usually an operator) a standard character. The syntax of the parser can be seen in action in the documentation of the package it.unimi.di.mg4j.search.
The parser returns a Query—an abstract representation of the query string that can be turned later into a DocumentIterator.
If a TermProcessor is specified, it will be applied to the terms found in the query string. This can lead to transformations (e.g., downcasing) or generate an exception if the query string contains terms filtered by the term processor.

Since:

1.0.1

Author:

Sebastiano Vigna, Paolo Boldi

Field Summary

Fields
Modifier and Type	Field and Description
`String`	`defaultIndex` The default index alias.
`Set<String>`	`indices` The set of index aliases.
`Token`	`jj_nt`
`boolean`	`lookingAhead`
`Map<String,? extends TermProcessor>`	`termProcessors` The term processor for each index.
`Token`	`token`
`SimpleParserTokenManager`	`token_source`

Fields inherited from interface it.unimi.di.mg4j.query.parser.SimpleParserConstants
ALIGN, AND, CLOSE_ENLARGE, CLOSE_PAREN, CLOSE_RANGE, CLOSE_REMAP, CLOSE_WEIGHT, COLON, DEFAULT, EOF, FALSE, HOLE, INTERVAL_SEPARATOR, MINUS, NOT, OAND, OPEN_ENLARGE, OPEN_PAREN, OPEN_RANGE, OPEN_REMAP, OPEN_WEIGHT, OR, PLUS, PREFIX, QUOTE, REMAP, SEMICOLON, SHARP, TILDA, tokenImage, TRUE, WORD

Constructor Summary

Constructors
Constructor and Description
`SimpleParser()` Creates a parser for a single nameless index with no term processing.
`SimpleParser(InputStream stream)`
`SimpleParser(InputStream stream, String encoding)`
`SimpleParser(Reader stream)`
`SimpleParser(Set<String> indices, String defaultIndex)` Creates a parser with no term processing.
`SimpleParser(Set<String> indices, String defaultIndex, Map<String,? extends TermProcessor> termProcessors)` Creates a parser.
`SimpleParser(SimpleParserTokenManager tm)`
`SimpleParser(TermProcessor termProcessor)` Creates a parser for a single nameless index with a given term processor.

Method Summary

Methods
Modifier and Type	Method and Description
`Query`	`alignQuery(String indexAlias)` Starting rule for an alignment query.
`Query`	`andQuery(String indexAlias)` Starting rule for an AND-query (the AND token is optional).
`Query`	`atomicQuery(String indexAlias)` Starting rule for an atomic query.
`Query`	`atomicSimpleQuery(String indexAlias)` Starting rule for an atomic simple query.
`SimpleParser`	`copy()`
`Query`	`differenceQuery(String indexAlias)` Starting rule for a difference query.
`void`	`disable_tracing()`
`void`	`enable_tracing()`
`MutableString`	`escape(MutableString token)` Escapes the provided mutable string, making it into a text token.
`String`	`escape(String token)` Escapes the provided string, making it into a text token.
`ParseException`	`generateParseException()`
`Token`	`getNextToken()`
`Token`	`getToken(int index)`
`Query`	`multiTermQuery(String indexAlias)` Starting rule for a multiterm query.
`Query`	`orderedAndQuery(String indexAlias)` Starting rule for an AND<-query.
`Query`	`orQuery(String indexAlias)` Starting rule for a OR-query.
`Query`	`parse(MutableString text)` Turns the given query mutable string into a composite `Query` object.
`Query`	`parse(String text)` Turns the given query string into a composite `Query` object.
`Query`	`query(String indexAlias)` Parser.
`Query`	`quotedQuery(String indexAlias)` Starting rule for a quoted query.
`void`	`ReInit(InputStream stream)`
`void`	`ReInit(InputStream stream, String encoding)`
`void`	`ReInit(Reader stream)`
`void`	`ReInit(SimpleParserTokenManager tm)`
`Query`	`remappedQuery(String indexAlias)` Starting rule for a remapped query.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - indices
```
public Set<String> indices
```
    The set of index aliases.
  - defaultIndex
```
public String defaultIndex
```
    The default index alias.
  - termProcessors
```
public Map<String,? extends TermProcessor> termProcessors
```
    The term processor for each index.
  - token_source
```
public SimpleParserTokenManager token_source
```
  - token
```
public Token token
```
  - jj_nt
```
public Token jj_nt
```
  - lookingAhead
```
public boolean lookingAhead
```
- Constructor Detail
  - SimpleParser
```
public SimpleParser(Set<String> indices,
            String defaultIndex,
            Map<String,? extends TermProcessor> termProcessors)
```
    Creates a parser.
    
    Parameters:
    indices - the set of index aliases.
    defaultIndex - the default index alias to be used when parsing the query.
    termProcessors - a map from index aliases to the corresponding term processor, or null for no term processing.
  - SimpleParser
```
public SimpleParser(Set<String> indices,
            String defaultIndex)
```
    Creates a parser with no term processing.
    
    Parameters:
    indices - the set of index aliases.
    defaultIndex - the default index alias to be used when parsing the query.
  - SimpleParser
```
public SimpleParser()
```
    Creates a parser for a single nameless index with no term processing.
    Parsers created by this constructor allow only nameless access, both in the query and in the interval-iterator methods.
  - SimpleParser
```
public SimpleParser(TermProcessor termProcessor)
```
    Creates a parser for a single nameless index with a given term processor.
    Parsers created by this constructor allow only nameless access, both in the query and in the interval-iterator methods.
  - SimpleParser
```
public SimpleParser(InputStream stream)
```
  - SimpleParser
```
public SimpleParser(InputStream stream,
            String encoding)
```
  - SimpleParser
```
public SimpleParser(Reader stream)
```
  - SimpleParser
```
public SimpleParser(SimpleParserTokenManager tm)
```
- Method Detail
  - copy
```
public SimpleParser copy()
```
    Specified by:
    
    copy in interface FlyweightPrototype<QueryParser>
  - escape
```
public String escape(String token)
```
    Description copied from interface: QueryParser
    
    Escapes the provided string, making it into a text token.
    
    Specified by:
    
    escape in interface QueryParser
    
    Parameters:
    token - a wannabe text token (maybe containing special characters, but no character below code 32).
    
    Returns:
    an escaped representation of token that will be interpreted as a text token by this parser.
  - escape
```
public MutableString escape(MutableString token)
```
    Description copied from interface: QueryParser
    
    Escapes the provided mutable string, making it into a text token.
    
    Specified by:
    
    escape in interface QueryParser
    
    Parameters:
    token - a wannabe text token (maybe containing special characters, but no character below code 32).
    
    Returns:
    token, escaped so that it will be interpreted as a text token by this parser.
  - parse
```
public Query parse(String text)
            throws QueryParserException
```
    Description copied from interface: QueryParser
    
    Turns the given query string into a composite Query object.
    
    Specified by:
    
    parse in interface QueryParser
    
    Parameters:
    text - a string representing a query.
    
    Returns:
    the corresponding composite object.
    
    Throws:
    
    QueryParserException
  - parse
```
public Query parse(MutableString text)
            throws QueryParserException
```
    Description copied from interface: QueryParser
    
    Turns the given query mutable string into a composite Query object.
    
    Specified by:
    
    parse in interface QueryParser
    
    Parameters:
    text - a mutable string representing a query.
    
    Returns:
    the corresponding composite object.
    
    Throws:
    
    QueryParserException
  - query
```
public final Query query(String indexAlias)
                  throws ParseException
```
    Parser.
    
    Throws:
    
    ParseException
  - remappedQuery
```
public final Query remappedQuery(String indexAlias)
                          throws ParseException
```
    Starting rule for a remapped query.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - differenceQuery
```
public final Query differenceQuery(String indexAlias)
                            throws ParseException
```
    Starting rule for a difference query.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - orQuery
```
public final Query orQuery(String indexAlias)
                    throws ParseException
```
    Starting rule for a OR-query.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - andQuery
```
public final Query andQuery(String indexAlias)
                     throws ParseException
```
    Starting rule for an AND-query (the AND token is optional).
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - orderedAndQuery
```
public final Query orderedAndQuery(String indexAlias)
                            throws ParseException
```
    Starting rule for an AND<-query.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - alignQuery
```
public final Query alignQuery(String indexAlias)
                       throws ParseException
```
    Starting rule for an alignment query.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - multiTermQuery
```
public final Query multiTermQuery(String indexAlias)
                           throws ParseException
```
    Starting rule for a multiterm query.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - quotedQuery
```
public final Query quotedQuery(String indexAlias)
                        throws ParseException
```
    Starting rule for a quoted query. Subqueries cannot change index.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - atomicQuery
```
public final Query atomicQuery(String indexAlias)
                        throws ParseException
```
    Starting rule for an atomic query. May be either an atomic simple query or a quoted query. It can optionally contain an index selector and a low-pass limit.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - atomicSimpleQuery
```
public final Query atomicSimpleQuery(String indexAlias)
                              throws ParseException
```
    Starting rule for an atomic simple query. May be either a word or a query enclosed within parentheses.
    
    Parameters:
    indexAlias - the index alias for the default index to be used for the query that is going to be parsed.
    
    Returns:
    the result of the query.
    
    Throws:
    
    ParseException
  - ReInit
```
public void ReInit(InputStream stream)
```
  - ReInit
```
public void ReInit(InputStream stream,
          String encoding)
```
  - ReInit
```
public void ReInit(Reader stream)
```
  - ReInit
```
public void ReInit(SimpleParserTokenManager 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()
```

Class SimpleParser

Field Summary

Fields inherited from interface it.unimi.di.mg4j.query.parser.SimpleParserConstants

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

indices

defaultIndex

termProcessors

token_source

token

jj_nt

lookingAhead

Constructor Detail

SimpleParser

SimpleParser

SimpleParser

SimpleParser

SimpleParser

SimpleParser

SimpleParser

SimpleParser

Method Detail

copy

escape

escape

parse

parse

query

remappedQuery

differenceQuery

orQuery

andQuery

orderedAndQuery

alignQuery

multiTermQuery

quotedQuery

atomicQuery

atomicSimpleQuery

ReInit

ReInit

ReInit

ReInit

getNextToken

getToken

generateParseException

enable_tracing

disable_tracing