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The Waikato Environment for Knowledge Analysis (WEKA), a machine
learning workbench. This version represents the developer version, the
"bleeding edge" of development, you could say. New functionality gets added
to this version.
/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see
*
* Julie Beth Lovins (1968). Development of a stemming algorithm. Mechanical Translation and Computational Linguistics. 11:22-31.
*
*
* BibTeX:
*
* @article{Lovins1968,
* author = {Julie Beth Lovins},
* journal = {Mechanical Translation and Computational Linguistics},
* pages = {22-31},
* title = {Development of a stemming algorithm},
* volume = {11},
* year = {1968}
* }
*
*
*
* @author Eibe Frank (eibe at cs dot waikato dot ac dot nz)
* @version $Revision: 8034 $
*/
public class LovinsStemmer
implements Stemmer, TechnicalInformationHandler {
/** for serialization */
static final long serialVersionUID = -6113024782588197L;
/** Enters C version compatibility mode if set to true (emulates
features of the original C implementation that are inconsistent
with the algorithm as described in Lovins's paper) */
private static boolean m_CompMode = false;
/** The hash tables containing the list of endings. */
private static HashMap m_l11 = null;
private static HashMap m_l10 = null;
private static HashMap m_l9 = null;
private static HashMap m_l8 = null;
private static HashMap m_l7 = null;
private static HashMap m_l6 = null;
private static HashMap m_l5 = null;
private static HashMap m_l4 = null;
private static HashMap m_l3 = null;
private static HashMap m_l2 = null;
private static HashMap m_l1 = null;
static {
m_l11 = new HashMap();
m_l11.put("alistically", "B");
m_l11.put("arizability", "A");
m_l11.put("izationally", "B");
m_l10 = new HashMap();
m_l10.put("antialness", "A");
m_l10.put("arisations", "A");
m_l10.put("arizations", "A");
m_l10.put("entialness", "A");
m_l9 = new HashMap();
m_l9.put("allically", "C");
m_l9.put("antaneous", "A");
m_l9.put("antiality", "A");
m_l9.put("arisation", "A");
m_l9.put("arization", "A");
m_l9.put("ationally", "B");
m_l9.put("ativeness", "A");
m_l9.put("eableness", "E");
m_l9.put("entations", "A");
m_l9.put("entiality", "A");
m_l9.put("entialize", "A");
m_l9.put("entiation", "A");
m_l9.put("ionalness", "A");
m_l9.put("istically", "A");
m_l9.put("itousness", "A");
m_l9.put("izability", "A");
m_l9.put("izational", "A");
m_l8 = new HashMap();
m_l8.put("ableness", "A");
m_l8.put("arizable", "A");
m_l8.put("entation", "A");
m_l8.put("entially", "A");
m_l8.put("eousness", "A");
m_l8.put("ibleness", "A");
m_l8.put("icalness", "A");
m_l8.put("ionalism", "A");
m_l8.put("ionality", "A");
m_l8.put("ionalize", "A");
m_l8.put("iousness", "A");
m_l8.put("izations", "A");
m_l8.put("lessness", "A");
m_l7 = new HashMap();
m_l7.put("ability", "A");
m_l7.put("aically", "A");
m_l7.put("alistic", "B");
m_l7.put("alities", "A");
m_l7.put("ariness", "E");
m_l7.put("aristic", "A");
m_l7.put("arizing", "A");
m_l7.put("ateness", "A");
m_l7.put("atingly", "A");
m_l7.put("ational", "B");
m_l7.put("atively", "A");
m_l7.put("ativism", "A");
m_l7.put("elihood", "E");
m_l7.put("encible", "A");
m_l7.put("entally", "A");
m_l7.put("entials", "A");
m_l7.put("entiate", "A");
m_l7.put("entness", "A");
m_l7.put("fulness", "A");
m_l7.put("ibility", "A");
m_l7.put("icalism", "A");
m_l7.put("icalist", "A");
m_l7.put("icality", "A");
m_l7.put("icalize", "A");
m_l7.put("ication", "G");
m_l7.put("icianry", "A");
m_l7.put("ination", "A");
m_l7.put("ingness", "A");
m_l7.put("ionally", "A");
m_l7.put("isation", "A");
m_l7.put("ishness", "A");
m_l7.put("istical", "A");
m_l7.put("iteness", "A");
m_l7.put("iveness", "A");
m_l7.put("ivistic", "A");
m_l7.put("ivities", "A");
m_l7.put("ization", "F");
m_l7.put("izement", "A");
m_l7.put("oidally", "A");
m_l7.put("ousness", "A");
m_l6 = new HashMap();
m_l6.put("aceous", "A");
m_l6.put("acious", "B");
m_l6.put("action", "G");
m_l6.put("alness", "A");
m_l6.put("ancial", "A");
m_l6.put("ancies", "A");
m_l6.put("ancing", "B");
m_l6.put("ariser", "A");
m_l6.put("arized", "A");
m_l6.put("arizer", "A");
m_l6.put("atable", "A");
m_l6.put("ations", "B");
m_l6.put("atives", "A");
m_l6.put("eature", "Z");
m_l6.put("efully", "A");
m_l6.put("encies", "A");
m_l6.put("encing", "A");
m_l6.put("ential", "A");
m_l6.put("enting", "C");
m_l6.put("entist", "A");
m_l6.put("eously", "A");
m_l6.put("ialist", "A");
m_l6.put("iality", "A");
m_l6.put("ialize", "A");
m_l6.put("ically", "A");
m_l6.put("icance", "A");
m_l6.put("icians", "A");
m_l6.put("icists", "A");
m_l6.put("ifully", "A");
m_l6.put("ionals", "A");
m_l6.put("ionate", "D");
m_l6.put("ioning", "A");
m_l6.put("ionist", "A");
m_l6.put("iously", "A");
m_l6.put("istics", "A");
m_l6.put("izable", "E");
m_l6.put("lessly", "A");
m_l6.put("nesses", "A");
m_l6.put("oidism", "A");
m_l5 = new HashMap();
m_l5.put("acies", "A");
m_l5.put("acity", "A");
m_l5.put("aging", "B");
m_l5.put("aical", "A");
if (!m_CompMode) {
m_l5.put("alist", "A");
}
m_l5.put("alism", "B");
m_l5.put("ality", "A");
m_l5.put("alize", "A");
m_l5.put("allic", "b");
m_l5.put("anced", "B");
m_l5.put("ances", "B");
m_l5.put("antic", "C");
m_l5.put("arial", "A");
m_l5.put("aries", "A");
m_l5.put("arily", "A");
m_l5.put("arity", "B");
m_l5.put("arize", "A");
m_l5.put("aroid", "A");
m_l5.put("ately", "A");
m_l5.put("ating", "I");
m_l5.put("ation", "B");
m_l5.put("ative", "A");
m_l5.put("ators", "A");
m_l5.put("atory", "A");
m_l5.put("ature", "E");
m_l5.put("early", "Y");
m_l5.put("ehood", "A");
m_l5.put("eless", "A");
if (!m_CompMode) {
m_l5.put("elily", "A");
} else {
m_l5.put("elity", "A");
}
m_l5.put("ement", "A");
m_l5.put("enced", "A");
m_l5.put("ences", "A");
m_l5.put("eness", "E");
m_l5.put("ening", "E");
m_l5.put("ental", "A");
m_l5.put("ented", "C");
m_l5.put("ently", "A");
m_l5.put("fully", "A");
m_l5.put("ially", "A");
m_l5.put("icant", "A");
m_l5.put("ician", "A");
m_l5.put("icide", "A");
m_l5.put("icism", "A");
m_l5.put("icist", "A");
m_l5.put("icity", "A");
m_l5.put("idine", "I");
m_l5.put("iedly", "A");
m_l5.put("ihood", "A");
m_l5.put("inate", "A");
m_l5.put("iness", "A");
m_l5.put("ingly", "B");
m_l5.put("inism", "J");
m_l5.put("inity", "c");
m_l5.put("ional", "A");
m_l5.put("ioned", "A");
m_l5.put("ished", "A");
m_l5.put("istic", "A");
m_l5.put("ities", "A");
m_l5.put("itous", "A");
m_l5.put("ively", "A");
m_l5.put("ivity", "A");
m_l5.put("izers", "F");
m_l5.put("izing", "F");
m_l5.put("oidal", "A");
m_l5.put("oides", "A");
m_l5.put("otide", "A");
m_l5.put("ously", "A");
m_l4 = new HashMap();
m_l4.put("able", "A");
m_l4.put("ably", "A");
m_l4.put("ages", "B");
m_l4.put("ally", "B");
m_l4.put("ance", "B");
m_l4.put("ancy", "B");
m_l4.put("ants", "B");
m_l4.put("aric", "A");
m_l4.put("arly", "K");
m_l4.put("ated", "I");
m_l4.put("ates", "A");
m_l4.put("atic", "B");
m_l4.put("ator", "A");
m_l4.put("ealy", "Y");
m_l4.put("edly", "E");
m_l4.put("eful", "A");
m_l4.put("eity", "A");
m_l4.put("ence", "A");
m_l4.put("ency", "A");
m_l4.put("ened", "E");
m_l4.put("enly", "E");
m_l4.put("eous", "A");
m_l4.put("hood", "A");
m_l4.put("ials", "A");
m_l4.put("ians", "A");
m_l4.put("ible", "A");
m_l4.put("ibly", "A");
m_l4.put("ical", "A");
m_l4.put("ides", "L");
m_l4.put("iers", "A");
m_l4.put("iful", "A");
m_l4.put("ines", "M");
m_l4.put("ings", "N");
m_l4.put("ions", "B");
m_l4.put("ious", "A");
m_l4.put("isms", "B");
m_l4.put("ists", "A");
m_l4.put("itic", "H");
m_l4.put("ized", "F");
m_l4.put("izer", "F");
m_l4.put("less", "A");
m_l4.put("lily", "A");
m_l4.put("ness", "A");
m_l4.put("ogen", "A");
m_l4.put("ward", "A");
m_l4.put("wise", "A");
m_l4.put("ying", "B");
m_l4.put("yish", "A");
m_l3 = new HashMap();
m_l3.put("acy", "A");
m_l3.put("age", "B");
m_l3.put("aic", "A");
m_l3.put("als", "b");
m_l3.put("ant", "B");
m_l3.put("ars", "O");
m_l3.put("ary", "F");
m_l3.put("ata", "A");
m_l3.put("ate", "A");
m_l3.put("eal", "Y");
m_l3.put("ear", "Y");
m_l3.put("ely", "E");
m_l3.put("ene", "E");
m_l3.put("ent", "C");
m_l3.put("ery", "E");
m_l3.put("ese", "A");
m_l3.put("ful", "A");
m_l3.put("ial", "A");
m_l3.put("ian", "A");
m_l3.put("ics", "A");
m_l3.put("ide", "L");
m_l3.put("ied", "A");
m_l3.put("ier", "A");
m_l3.put("ies", "P");
m_l3.put("ily", "A");
m_l3.put("ine", "M");
m_l3.put("ing", "N");
m_l3.put("ion", "Q");
m_l3.put("ish", "C");
m_l3.put("ism", "B");
m_l3.put("ist", "A");
m_l3.put("ite", "a");
m_l3.put("ity", "A");
m_l3.put("ium", "A");
m_l3.put("ive", "A");
m_l3.put("ize", "F");
m_l3.put("oid", "A");
m_l3.put("one", "R");
m_l3.put("ous", "A");
m_l2 = new HashMap();
m_l2.put("ae", "A");
m_l2.put("al", "b");
m_l2.put("ar", "X");
m_l2.put("as", "B");
m_l2.put("ed", "E");
m_l2.put("en", "F");
m_l2.put("es", "E");
m_l2.put("ia", "A");
m_l2.put("ic", "A");
m_l2.put("is", "A");
m_l2.put("ly", "B");
m_l2.put("on", "S");
m_l2.put("or", "T");
m_l2.put("um", "U");
m_l2.put("us", "V");
m_l2.put("yl", "R");
m_l2.put("s\'", "A");
m_l2.put("\'s", "A");
m_l1 = new HashMap();
m_l1.put("a", "A");
m_l1.put("e", "A");
m_l1.put("i", "A");
m_l1.put("o", "A");
m_l1.put("s", "W");
m_l1.put("y", "B");
}
/**
* Returns a string describing the stemmer
* @return a description suitable for
* displaying in the explorer/experimenter gui
*/
public String globalInfo() {
return
"A stemmer based on the Lovins stemmer, described here:\n\n"
+ getTechnicalInformation().toString();
}
/**
* Returns an instance of a TechnicalInformation object, containing
* detailed information about the technical background of this class,
* e.g., paper reference or book this class is based on.
*
* @return the technical information about this class
*/
public TechnicalInformation getTechnicalInformation() {
TechnicalInformation result;
result = new TechnicalInformation(Type.ARTICLE);
result.setValue(Field.AUTHOR, "Julie Beth Lovins");
result.setValue(Field.YEAR, "1968");
result.setValue(Field.TITLE, "Development of a stemming algorithm");
result.setValue(Field.JOURNAL, "Mechanical Translation and Computational Linguistics");
result.setValue(Field.VOLUME, "11");
result.setValue(Field.PAGES, "22-31");
return result;
}
/**
* Finds and removes ending from given word.
*
* @param word the word to work on
* @return the processed word
*/
private String removeEnding(String word) {
int length = word.length();
int el = 11;
while (el > 0) {
if (length - el > 1) {
String ending = word.substring(length - el);
String conditionCode = null;
switch (el) {
case 11: conditionCode = (String)m_l11.get(ending);
break;
case 10: conditionCode = (String)m_l10.get(ending);
break;
case 9: conditionCode = (String)m_l9.get(ending);
break;
case 8: conditionCode = (String)m_l8.get(ending);
break;
case 7: conditionCode = (String)m_l7.get(ending);
break;
case 6: conditionCode = (String)m_l6.get(ending);
break;
case 5: conditionCode = (String)m_l5.get(ending);
break;
case 4: conditionCode = (String)m_l4.get(ending);
break;
case 3: conditionCode = (String)m_l3.get(ending);
break;
case 2: conditionCode = (String)m_l2.get(ending);
break;
case 1: conditionCode = (String)m_l1.get(ending);
break;
default:
}
if (conditionCode != null) {
switch (conditionCode.charAt(0)) {
case 'A':
return word.substring(0, length - el);
case 'B':
if (length - el > 2) {
return word.substring(0, length - el);
}
break;
case 'C':
if (length - el > 3) {
return word.substring(0, length - el);
}
break;
case 'D':
if (length - el > 4) {
return word.substring(0, length - el);
}
break;
case 'E':
if (word.charAt(length - el - 1) != 'e') {
return word.substring(0, length - el);
}
break;
case 'F':
if ((length - el > 2) &&
(word.charAt(length - el - 1) != 'e')) {
return word.substring(0, length - el);
}
break;
case 'G':
if ((length - el > 2) &&
(word.charAt(length - el - 1) == 'f')) {
return word.substring(0, length - el);
}
break;
case 'H':
if ((word.charAt(length - el - 1) == 't') ||
((word.charAt(length - el - 1) == 'l') &&
(word.charAt(length - el - 2) == 'l'))) {
return word.substring(0, length - el);
}
break;
case 'I':
if ((word.charAt(length - el - 1) != 'o') &&
(word.charAt(length - el - 1) != 'e')) {
return word.substring(0, length - el);
}
break;
case 'J':
if ((word.charAt(length - el - 1) != 'a') &&
(word.charAt(length - el - 1) != 'e')) {
return word.substring(0, length - el);
}
break;
case 'K':
if ((length - el > 2) &&
((word.charAt(length - el - 1) == 'l') ||
(word.charAt(length - el - 1) == 'i') ||
((word.charAt(length - el - 1) == 'e') &&
(word.charAt(length - el - 3) == 'u')))) {
return word.substring(0, length - el);
}
break;
case 'L':
if ((word.charAt(length - el - 1) != 'u') &&
(word.charAt(length - el - 1) != 'x') &&
((word.charAt(length - el - 1) != 's') ||
(word.charAt(length - el - 2) == 'o'))) {
return word.substring(0, length - el);
}
break;
case 'M':
if ((word.charAt(length - el - 1) != 'a') &&
(word.charAt(length - el - 1) != 'c') &&
(word.charAt(length - el - 1) != 'e') &&
(word.charAt(length - el - 1) != 'm')) {
return word.substring(0, length - el);
}
break;
case 'N':
if ((length - el > 3) ||
((length - el == 3) &&
((word.charAt(length - el - 3) != 's')))) {
return word.substring(0, length - el);
}
break;
case 'O':
if ((word.charAt(length - el - 1) == 'l') ||
(word.charAt(length - el - 1) == 'i')) {
return word.substring(0, length - el);
}
break;
case 'P':
if (word.charAt(length - el - 1) != 'c') {
return word.substring(0, length - el);
}
break;
case 'Q':
if ((length - el > 2) &&
(word.charAt(length - el - 1) != 'l') &&
(word.charAt(length - el - 1) != 'n')) {
return word.substring(0, length - el);
}
break;
case 'R':
if ((word.charAt(length - el - 1) == 'n') ||
(word.charAt(length - el - 1) == 'r')) {
return word.substring(0, length - el);
}
break;
case 'S':
if (((word.charAt(length - el - 1) == 'r') &&
(word.charAt(length - el - 2) == 'd')) ||
((word.charAt(length - el - 1) == 't') &&
(word.charAt(length - el - 2) != 't'))) {
return word.substring(0, length - el);
}
break;
case 'T':
if ((word.charAt(length - el - 1) == 's') ||
((word.charAt(length - el - 1) == 't') &&
(word.charAt(length - el - 2) != 'o'))) {
return word.substring(0, length - el);
}
break;
case 'U':
if ((word.charAt(length - el - 1) == 'l') ||
(word.charAt(length - el - 1) == 'm') ||
(word.charAt(length - el - 1) == 'n') ||
(word.charAt(length - el - 1) == 'r')) {
return word.substring(0, length - el);
}
break;
case 'V':
if (word.charAt(length - el - 1) == 'c') {
return word.substring(0, length - el);
}
break;
case 'W':
if ((word.charAt(length - el - 1) != 's') &&
(word.charAt(length - el - 1) != 'u')) {
return word.substring(0, length - el);
}
break;
case 'X':
if ((word.charAt(length - el - 1) == 'l') ||
(word.charAt(length - el - 1) == 'i') ||
((length - el > 2) &&
(word.charAt(length - el - 1) == 'e') &&
(word.charAt(length - el - 3) == 'u'))) {
return word.substring(0, length - el);
}
break;
case 'Y':
if ((word.charAt(length - el - 1) == 'n') &&
(word.charAt(length - el - 2) == 'i')) {
return word.substring(0, length - el);
}
break;
case 'Z':
if (word.charAt(length - el - 1) != 'f') {
return word.substring(0, length - el);
}
break;
case 'a':
if ((word.charAt(length - el - 1) == 'd') ||
(word.charAt(length - el - 1) == 'f') ||
(((word.charAt(length - el - 1) == 'h') &&
(word.charAt(length - el - 2) == 'p'))) ||
(((word.charAt(length - el - 1) == 'h') &&
(word.charAt(length - el - 2) == 't'))) ||
(word.charAt(length - el - 1) == 'l') ||
(((word.charAt(length - el - 1) == 'r') &&
(word.charAt(length - el - 2) == 'e'))) ||
(((word.charAt(length - el - 1) == 'r') &&
(word.charAt(length - el - 2) == 'o'))) ||
(((word.charAt(length - el - 1) == 's') &&
(word.charAt(length - el - 2) == 'e'))) ||
(word.charAt(length - el - 1) == 't')) {
return word.substring(0, length - el);
}
break;
case 'b':
if (m_CompMode) {
if (((length - el == 3 ) &&
(!((word.charAt(length - el - 1) == 't') &&
(word.charAt(length - el - 2) == 'e') &&
(word.charAt(length - el - 3) == 'm')))) ||
((length - el > 3) &&
(!((word.charAt(length - el - 1) == 't') &&
(word.charAt(length - el - 2) == 's') &&
(word.charAt(length - el - 3) == 'y') &&
(word.charAt(length - el - 4) == 'r'))))) {
return word.substring(0, length - el);
}
} else {
if ((length - el > 2) &&
(!((word.charAt(length - el - 1) == 't') &&
(word.charAt(length - el - 2) == 'e') &&
(word.charAt(length - el - 3) == 'm'))) &&
((length - el < 4) ||
(!((word.charAt(length - el - 1) == 't') &&
(word.charAt(length - el - 2) == 's') &&
(word.charAt(length - el - 3) == 'y') &&
(word.charAt(length - el - 4) == 'r'))))) {
return word.substring(0, length - el);
}
}
break;
case 'c':
if (word.charAt(length - el - 1) == 'l') {
return word.substring(0, length - el);
}
break;
default:
throw new IllegalArgumentException("Fatal error.");
}
}
}
el--;
}
return word;
}
/**
* Recodes ending of given word.
*
* @param word the word to work on
* @return the processed word
*/
private String recodeEnding(String word) {
int lastPos = word.length() - 1;
// Rule 1
if (word.endsWith("bb") ||
word.endsWith("dd") ||
word.endsWith("gg") ||
word.endsWith("ll") ||
word.endsWith("mm") ||
word.endsWith("nn") ||
word.endsWith("pp") ||
word.endsWith("rr") ||
word.endsWith("ss") ||
word.endsWith("tt")) {
word = word.substring(0, lastPos);
lastPos--;
}
// Rule 2
if (word.endsWith("iev")) {
word = word.substring(0, lastPos - 2).concat("ief");
}
// Rule 3
if (word.endsWith("uct")) {
word = word.substring(0, lastPos - 2).concat("uc");
lastPos--;
}
// Rule 4
if (word.endsWith("umpt")) {
word = word.substring(0, lastPos - 3).concat("um");
lastPos -= 2;
}
// Rule 5
if (word.endsWith("rpt")) {
word = word.substring(0, lastPos - 2).concat("rb");
lastPos--;
}
// Rule 6
if (word.endsWith("urs")) {
word = word.substring(0, lastPos - 2).concat("ur");
lastPos--;
}
// Rule 7
if (word.endsWith("istr")) {
word = word.substring(0, lastPos - 3).concat("ister");
lastPos++;
}
// Rule 7a
if (word.endsWith("metr")) {
word = word.substring(0, lastPos - 3).concat("meter");
lastPos++;
}
// Rule 8
if (word.endsWith("olv")) {
word = word.substring(0, lastPos - 2).concat("olut");
lastPos++;
}
// Rule 9
if (word.endsWith("ul")) {
if ((lastPos - 2 < 0) ||
((word.charAt(lastPos - 2) != 'a') &&
(word.charAt(lastPos - 2) != 'i') &&
(word.charAt(lastPos - 2) != 'o'))) {
word = word.substring(0, lastPos - 1).concat("l");
lastPos--;
}
}
// Rule 10
if (word.endsWith("bex")) {
word = word.substring(0, lastPos - 2).concat("bic");
}
// Rule 11
if (word.endsWith("dex")) {
word = word.substring(0, lastPos - 2).concat("dic");
}
// Rule 12
if (word.endsWith("pex")) {
word = word.substring(0, lastPos - 2).concat("pic");
}
// Rule 13
if (word.endsWith("tex")) {
word = word.substring(0, lastPos - 2).concat("tic");
}
// Rule 14
if (word.endsWith("ax")) {
word = word.substring(0, lastPos - 1).concat("ac");
}
// Rule 15
if (word.endsWith("ex")) {
word = word.substring(0, lastPos - 1).concat("ec");
}
// Rule 16
if (word.endsWith("ix")) {
word = word.substring(0, lastPos - 1).concat("ic");
}
// Rule 17
if (word.endsWith("lux")) {
word = word.substring(0, lastPos - 2).concat("luc");
}
// Rule 18
if (word.endsWith("uad")) {
word = word.substring(0, lastPos - 2).concat("uas");
}
// Rule 19
if (word.endsWith("vad")) {
word = word.substring(0, lastPos - 2).concat("vas");
}
// Rule 20
if (word.endsWith("cid")) {
word = word.substring(0, lastPos - 2).concat("cis");
}
// Rule 21
if (word.endsWith("lid")) {
word = word.substring(0, lastPos - 2).concat("lis");
}
// Rule 22
if (word.endsWith("erid")) {
word = word.substring(0, lastPos - 3).concat("eris");
}
// Rule 23
if (word.endsWith("pand")) {
word = word.substring(0, lastPos - 3).concat("pans");
}
// Rule 24
if (word.endsWith("end")) {
if ((lastPos - 3 < 0) ||
(word.charAt(lastPos - 3) != 's')) {
word = word.substring(0, lastPos - 2).concat("ens");
}
}
// Rule 25
if (word.endsWith("ond")) {
word = word.substring(0, lastPos - 2).concat("ons");
}
// Rule 26
if (word.endsWith("lud")) {
word = word.substring(0, lastPos - 2).concat("lus");
}
// Rule 27
if (word.endsWith("rud")) {
word = word.substring(0, lastPos - 2).concat("rus");
}
// Rule 28
if (word.endsWith("her")) {
if ((lastPos - 3 < 0) ||
((word.charAt(lastPos - 3) != 'p') &&
(word.charAt(lastPos - 3) != 't'))) {
word = word.substring(0, lastPos - 2).concat("hes");
}
}
// Rule 29
if (word.endsWith("mit")) {
word = word.substring(0, lastPos - 2).concat("mis");
}
// Rule 30
if (word.endsWith("end")) {
if ((lastPos - 3 < 0) ||
(word.charAt(lastPos - 3) != 'm')) {
word = word.substring(0, lastPos - 2).concat("ens");
}
}
// Rule 31
if (word.endsWith("ert")) {
word = word.substring(0, lastPos - 2).concat("ers");
}
// Rule 32
if (word.endsWith("et")) {
if ((lastPos - 2 < 0) ||
(word.charAt(lastPos - 2) != 'n')) {
word = word.substring(0, lastPos - 1).concat("es");
}
}
// Rule 33
if (word.endsWith("yt")) {
word = word.substring(0, lastPos - 1).concat("ys");
}
// Rule 34
if (word.endsWith("yz")) {
word = word.substring(0, lastPos - 1).concat("ys");
}
return word;
}
/**
* Returns the stemmed version of the given word.
* Word is converted to lower case before stemming.
*
* @param word a string consisting of a single word
* @return the stemmed word
*/
public String stem(String word) {
if (word.length() > 2) {
return recodeEnding(removeEnding(word.toLowerCase()));
} else {
return word.toLowerCase();
}
}
/**
* Stems everything in the given string. String
* is converted to lower case before stemming.
*
* @param str the string to stem
* @return the processed string
*/
public String stemString(String str) {
StringBuffer result = new StringBuffer();
int start = -1;
for (int j = 0; j < str.length(); j++) {
char c = str.charAt(j);
if (Character.isLetterOrDigit(c)) {
if (start == -1) {
start = j;
}
} else if (c == '\'') {
if (start == -1) {
result.append(c);
}
} else {
if (start != -1) {
result.append(stem(str.substring(start, j)));
start = -1;
}
result.append(c);
}
}
if (start != -1) {
result.append(stem(str.substring(start, str.length())));
}
return result.toString();
}
/**
* returns a string representation of the stemmer
*
* @return a string representation of the stemmer
*/
public String toString() {
return getClass().getName();
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 8034 $");
}
/**
* Runs the stemmer with the given options
*
* @param args the options
*/
public static void main(String[] args) {
try {
Stemming.useStemmer(new LovinsStemmer(), args);
}
catch (Exception e) {
e.printStackTrace();
}
}
}
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