gate.creole.annic.apache.lucene.analysis
Class Token

java.lang.Object
  gate.creole.annic.apache.lucene.analysis.Token

All Implemented Interfaces:

Serializable

public final class Token
extends Object
implements Serializable

See Also:

Serialized Form

Constructor Summary

Token(String text, int start, int end)
Constructs a Token with the given term text, and start & end offsets.

Token(String text, int start, int end, String typ)
Constructs a Token with the given text, start and end offsets, & type.

Method Summary

int	endOffset() Returns this Token's ending offset, one greater than the position of the last character corresponding to this token in the source text.
int	getPosition()
int	getPositionIncrement() Returns the position increment of this Token.
void	setPosition(int pos)
void	setPositionIncrement(int positionIncrement) Set the position increment.
int	startOffset() Returns this Token's starting offset, the position of the first character corresponding to this token in the source text.
String	termText() Returns the Token's term text.
String	type() Returns this Token's lexical type.

Methods inherited from class java.lang.Object

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

Constructor Detail

Token

public Token(String text,
             int start,
             int end)

Constructs a Token with the given term text, and start & end offsets. The type defaults to "word."

Token

public Token(String text,
             int start,
             int end,
             String typ)

Constructs a Token with the given text, start and end offsets, & type.

Method Detail

setPositionIncrement

public void setPositionIncrement(int positionIncrement)

Set the position increment. This determines the position of this token relative to the previous Token in a TokenStream, used in phrase searching.

The default value is one.

Some common uses for this are:

• Set it to zero to put multiple terms in the same position. This is useful if, e.g., a word has multiple stems. Searches for phrases including either stem will match. In this case, all but the first stem's increment should be set to zero: the increment of the first instance should be one. Repeating a token with an increment of zero can also be used to boost the scores of matches on that token.
• Set it to values greater than one to inhibit exact phrase matches. If, for example, one does not want phrases to match across removed stop words, then one could build a stop word filter that removes stop words and also sets the increment to the number of stop words removed before each non-stop word. Then exact phrase queries will only match when the terms occur with no intervening stop words.

See Also:

TermPositions

setPosition

public void setPosition(int pos)

getPosition

public int getPosition()

getPositionIncrement

public int getPositionIncrement()

Returns the position increment of this Token.

See Also:

setPositionIncrement(int)

termText

public final String termText()

Returns the Token's term text.

startOffset

public final int startOffset()

Returns this Token's starting offset, the position of the first character corresponding to this token in the source text. Note that the difference between endOffset() and startOffset() may not be equal to termText.length(), as the term text may have been altered by a stemmer or some other filter.

endOffset

public final int endOffset()

Returns this Token's ending offset, one greater than the position of the last character corresponding to this token in the source text.

type

public final String type()

Returns this Token's lexical type. Defaults to "word".