| Methods Summary |
|---|
| 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.
if (b.length <= i + EXTRA) {
char[] new_b = new char[b.length+INC];
for (int c = 0; c < b.length; c++)
new_b[c] = b[c];
b = new_b;
}
b[i++] = ch;
|
| private final boolean | cons(int i)
switch (b[i]) {
case 'a": case 'e": case 'i": case 'o": case 'u":
return false;
case 'y":
return (i==k0) ? true : !cons(i-1);
default:
return true;
}
|
| private final boolean | cvc(int i)
if (i < k0+2 || !cons(i) || cons(i-1) || !cons(i-2))
return false;
else {
int ch = b[i];
if (ch == 'w" || ch == 'x" || ch == 'y") return false;
}
return true;
|
| private final boolean | doublec(int j)
if (j < k0+1)
return false;
if (b[j] != b[j-1])
return false;
return cons(j);
|
| private final boolean | ends(java.lang.String s)
int l = s.length();
int o = k-l+1;
if (o < k0)
return false;
for (int i = 0; i < l; i++)
if (b[o+i] != s.charAt(i))
return false;
j = k-l;
return true;
|
| 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. return b;
|
| public int | getResultLength()Returns the length of the word resulting from the stemming process. return i;
|
| private final int | m()
int n = 0;
int i = k0;
while(true) {
if (i > j)
return n;
if (! cons(i))
break;
i++;
}
i++;
while(true) {
while(true) {
if (i > j)
return n;
if (cons(i))
break;
i++;
}
i++;
n++;
while(true) {
if (i > j)
return n;
if (! cons(i))
break;
i++;
}
i++;
}
|
| public static void | main(java.lang.String[] args)Test program for demonstrating the Stemmer. It reads a file and
stems each word, writing the result to standard out.
Usage: Stemmer file-name
PorterStemmer s = new PorterStemmer();
for (int i = 0; i < args.length; i++) {
try {
InputStream in = new FileInputStream(args[i]);
byte[] buffer = new byte[1024];
int bufferLen, offset, ch;
bufferLen = in.read(buffer);
offset = 0;
s.reset();
while(true) {
if (offset < bufferLen)
ch = buffer[offset++];
else {
bufferLen = in.read(buffer);
offset = 0;
if (bufferLen < 0)
ch = -1;
else
ch = buffer[offset++];
}
if (Character.isLetter((char) ch)) {
s.add(Character.toLowerCase((char) ch));
}
else {
s.stem();
System.out.print(s.toString());
s.reset();
if (ch < 0)
break;
else {
System.out.print((char) ch);
}
}
}
in.close();
}
catch (IOException e) {
System.out.println("error reading " + args[i]);
}
}
|
| void | r(java.lang.String s) if (m() > 0) setto(s);
|
| 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. i = 0; dirty = false;
|
| void | setto(java.lang.String s)
int l = s.length();
int o = j+1;
for (int i = 0; i < l; i++)
b[o+i] = s.charAt(i);
k = j+l;
dirty = true;
|
| public java.lang.String | stem(java.lang.String s)Stem a word provided as a String. Returns the result as a String.
if (stem(s.toCharArray(), s.length()))
return toString();
else
return s;
|
| 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().
return stem(word, word.length);
|
| 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().
reset();
if (b.length < wordLen) {
char[] new_b = new char[wordLen + EXTRA];
b = new_b;
}
for (int j=0; j<wordLen; j++)
b[j] = wordBuffer[offset+j];
i = wordLen;
return stem(0);
|
| 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().
return stem(word, 0, wordLen);
|
| 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().
return stem(0);
|
| public boolean | stem(int i0)
k = i - 1;
k0 = i0;
if (k > k0+1) {
step1(); step2(); step3(); step4(); step5(); step6();
}
// Also, a word is considered dirty if we lopped off letters
// Thanks to Ifigenia Vairelles for pointing this out.
if (i != k+1)
dirty = true;
i = k+1;
return dirty;
|
| private final void | step1()
if (b[k] == 's") {
if (ends("sses")) k -= 2;
else if (ends("ies")) setto("i");
else if (b[k-1] != 's") k--;
}
if (ends("eed")) {
if (m() > 0)
k--;
}
else if ((ends("ed") || ends("ing")) && vowelinstem()) {
k = j;
if (ends("at")) setto("ate");
else if (ends("bl")) setto("ble");
else if (ends("iz")) setto("ize");
else if (doublec(k)) {
int ch = b[k--];
if (ch == 'l" || ch == 's" || ch == 'z")
k++;
}
else if (m() == 1 && cvc(k))
setto("e");
}
|
| private final void | step2()
if (ends("y") && vowelinstem()) {
b[k] = 'i";
dirty = true;
}
|
| private final void | step3()
if (k == k0) return; /* For Bug 1 */
switch (b[k-1]) {
case 'a":
if (ends("ational")) { r("ate"); break; }
if (ends("tional")) { r("tion"); break; }
break;
case 'c":
if (ends("enci")) { r("ence"); break; }
if (ends("anci")) { r("ance"); break; }
break;
case 'e":
if (ends("izer")) { r("ize"); break; }
break;
case 'l":
if (ends("bli")) { r("ble"); break; }
if (ends("alli")) { r("al"); break; }
if (ends("entli")) { r("ent"); break; }
if (ends("eli")) { r("e"); break; }
if (ends("ousli")) { r("ous"); break; }
break;
case 'o":
if (ends("ization")) { r("ize"); break; }
if (ends("ation")) { r("ate"); break; }
if (ends("ator")) { r("ate"); break; }
break;
case 's":
if (ends("alism")) { r("al"); break; }
if (ends("iveness")) { r("ive"); break; }
if (ends("fulness")) { r("ful"); break; }
if (ends("ousness")) { r("ous"); break; }
break;
case 't":
if (ends("aliti")) { r("al"); break; }
if (ends("iviti")) { r("ive"); break; }
if (ends("biliti")) { r("ble"); break; }
break;
case 'g":
if (ends("logi")) { r("log"); break; }
}
|
| private final void | step4()
switch (b[k]) {
case 'e":
if (ends("icate")) { r("ic"); break; }
if (ends("ative")) { r(""); break; }
if (ends("alize")) { r("al"); break; }
break;
case 'i":
if (ends("iciti")) { r("ic"); break; }
break;
case 'l":
if (ends("ical")) { r("ic"); break; }
if (ends("ful")) { r(""); break; }
break;
case 's":
if (ends("ness")) { r(""); break; }
break;
}
|
| private final void | step5()
if (k == k0) return; /* for Bug 1 */
switch (b[k-1]) {
case 'a":
if (ends("al")) break;
return;
case 'c":
if (ends("ance")) break;
if (ends("ence")) break;
return;
case 'e":
if (ends("er")) break; return;
case 'i":
if (ends("ic")) break; return;
case 'l":
if (ends("able")) break;
if (ends("ible")) break; return;
case 'n":
if (ends("ant")) break;
if (ends("ement")) break;
if (ends("ment")) break;
/* element etc. not stripped before the m */
if (ends("ent")) break;
return;
case 'o":
if (ends("ion") && j >= 0 && (b[j] == 's" || b[j] == 't")) break;
/* j >= 0 fixes Bug 2 */
if (ends("ou")) break;
return;
/* takes care of -ous */
case 's":
if (ends("ism")) break;
return;
case 't":
if (ends("ate")) break;
if (ends("iti")) break;
return;
case 'u":
if (ends("ous")) break;
return;
case 'v":
if (ends("ive")) break;
return;
case 'z":
if (ends("ize")) break;
return;
default:
return;
}
if (m() > 1)
k = j;
|
| private final void | step6()
j = k;
if (b[k] == 'e") {
int a = m();
if (a > 1 || a == 1 && !cvc(k-1))
k--;
}
if (b[k] == 'l" && doublec(k) && m() > 1)
k--;
|
| 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.) return new String(b,0,i);
|
| private final boolean | vowelinstem()
int i;
for (i = k0; i <= j; i++)
if (! cons(i))
return true;
return false;
|
