Package org.ujmp.core.util
Class PorterStemmer
java.lang.Object
org.ujmp.core.util.PorterStemmer
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.
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Field Summary
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
add
(char ch) Add a character to the word being stemmed.void
add
(char[] w, int wLen) Adds wLen characters to the word being stemmed contained in a portion of a char[] array.private final boolean
cons
(int i) private final boolean
cvc
(int i) private final boolean
doublec
(int j) private final boolean
char[]
Returns a reference to a character buffer containing the results of the stemming process.int
Returns the length of the word resulting from the stemming process.private final int
m()
static void
Test program for demonstrating the Stemmer.private final void
private final void
void
stem()
Stem the word placed into the Stemmer buffer through calls to add().Stem a word provided as a String.private final void
step1()
private final void
step2()
private final void
step3()
private final void
step4()
private final void
step5()
private final void
step6()
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 final boolean
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Field Details
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b
private char[] b -
i
private int i -
i_end
private int i_end -
j
private int j -
k
private int k -
INC
private static final int INC- See Also:
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Constructor Details
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PorterStemmer
public PorterStemmer()
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Method Details
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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 stem the word. -
add
public void add(char[] w, int wLen) Adds wLen characters to the word being stemmed contained in a portion of a char[] array. This is like repeated calls of add(char ch), but faster. -
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.) -
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
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setto
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r
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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
Stem a word provided as a String. Returns the result as a String. -
stem
public void 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(). -
main
Test program for demonstrating the Stemmer. It reads text from a a list of files, stems each word, and writes the result to standard output. Note that the word stemmed is expected to be in lower case: forcing lower case must be done outside the Stemmer class. Usage: Stemmer file-name file-name ...
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