Package org.apache.lucene.analysis.en

Class PorterStemmer

java.lang.Object

org.apache.lucene.analysis.en.PorterStemmer

class PorterStemmer
extends java.lang.Object

Stemmer, implementing the Porter Stemming Algorithm The Stemmer class transforms a word into its root form. The input word can be provided a character at time (by calling add()), or at once by calling one of the various stem(something) methods.

Field Summary

Fields

Modifier and Type	Field	Description
private char[]	b
private boolean	dirty
private int	i
private static int	INITIAL_SIZE
private int	j
private int	k
private int	k0

Constructor Summary

Constructors

Constructor	Description
PorterStemmer()

Method Summary

Modifier and Type	Method	Description
void	add(char ch)	Add a character to the word being stemmed.
private boolean	cons(int i)
private boolean	cvc(int i)
private boolean	doublec(int j)
private boolean	ends(java.lang.String s)
char[]	getResultBuffer()	Returns a reference to a character buffer containing the results of the stemming process.
int	getResultLength()	Returns the length of the word resulting from the stemming process.
private int	m()
(package private) void	r(java.lang.String s)
void	reset()	reset() resets the stemmer so it can stem another word.
(package private) void	setto(java.lang.String s)
boolean	stem()	Stem the word placed into the Stemmer buffer through calls to add().
boolean	stem(char[] word)	Stem a word contained in a char[].
boolean	stem(char[] word, int wordLen)	Stem a word contained in a leading portion of a char[] array.
boolean	stem(char[] wordBuffer, int offset, int wordLen)	Stem a word contained in a portion of a char[] array.
boolean	stem(int i0)
java.lang.String	stem(java.lang.String s)	Stem a word provided as a String.
private void	step1()
private void	step2()
private void	step3()
private void	step4()
private void	step5()
private void	step6()
java.lang.String	toString()	After a word has been stemmed, it can be retrieved by toString(), or a reference to the internal buffer can be retrieved by getResultBuffer and getResultLength (which is generally more efficient.)
private boolean	vowelinstem()

Methods inherited from class java.lang.Object

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

Field Detail

b

private char[] b

i

private int i

j

private int j

k

private int k

k0

private int k0

dirty

private boolean dirty

INITIAL_SIZE

private static final int INITIAL_SIZE

See Also:

Constant Field Values

Constructor Detail

PorterStemmer

public PorterStemmer()

Method Detail

reset

public void reset()

reset() resets the stemmer so it can stem another word. If you invoke the stemmer by calling add(char) and then stem(), you must call reset() before starting another word.

add

public void add(char ch)

Add a character to the word being stemmed. When you are finished adding characters, you can call stem(void) to process the word.

toString

public java.lang.String toString()

After a word has been stemmed, it can be retrieved by toString(), or a reference to the internal buffer can be retrieved by getResultBuffer and getResultLength (which is generally more efficient.)

Overrides:

toString in class java.lang.Object

getResultLength

public int getResultLength()

Returns the length of the word resulting from the stemming process.

getResultBuffer

public char[] getResultBuffer()

Returns a reference to a character buffer containing the results of the stemming process. You also need to consult getResultLength() to determine the length of the result.

cons

private final boolean cons(int i)

m

private final int m()

vowelinstem

private final boolean vowelinstem()

doublec

private final boolean doublec(int j)

cvc

private final boolean cvc(int i)

ends

private final boolean ends(java.lang.String s)

setto

void setto(java.lang.String s)

r

void r(java.lang.String s)

step1

private final void step1()

step2

private final void step2()

step3

private final void step3()

step4

private final void step4()

step5

private final void step5()

step6

private final void step6()

stem

public java.lang.String stem(java.lang.String s)

Stem a word provided as a String. Returns the result as a String.

stem

public boolean stem(char[] word)

Stem a word contained in a char[]. Returns true if the stemming process resulted in a word different from the input. You can retrieve the result with getResultLength()/getResultBuffer() or toString().

stem

public boolean stem(char[] wordBuffer,
                    int offset,
                    int wordLen)

Stem a word contained in a portion of a char[] array. Returns true if the stemming process resulted in a word different from the input. You can retrieve the result with getResultLength()/getResultBuffer() or toString().

stem

public boolean stem(char[] word,
                    int wordLen)

Stem a word contained in a leading portion of a char[] array. Returns true if the stemming process resulted in a word different from the input. You can retrieve the result with getResultLength()/getResultBuffer() or toString().

stem

public boolean stem()

Stem the word placed into the Stemmer buffer through calls to add(). Returns true if the stemming process resulted in a word different from the input. You can retrieve the result with getResultLength()/getResultBuffer() or toString().

stem

public boolean stem(int i0)