lucene/analysis/common/src/test/org/apache/lucene/analysis/lv/TestLatvianStemmer.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.lucene.analysis.lv;

import java.io.IOException;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.BaseTokenStreamTestCase;
import org.apache.lucene.analysis.MockTokenizer;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.core.KeywordTokenizer;

/** Basic tests for {@link LatvianStemmer} */
public class TestLatvianStemmer extends BaseTokenStreamTestCase {
  private Analyzer a;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    a =
        new Analyzer() {
          @Override
          protected TokenStreamComponents createComponents(String fieldName) {
            Tokenizer tokenizer = new MockTokenizer(MockTokenizer.WHITESPACE, false);
            return new TokenStreamComponents(tokenizer, new LatvianStemFilter(tokenizer));
          }
        };
  }

  @Override
  public void tearDown() throws Exception {
    a.close();
    super.tearDown();
  }

  public void testNouns1() throws IOException {
    // decl. I
    checkOneTerm(a, "tēvs", "tēv"); // nom. sing.
    checkOneTerm(a, "tēvi", "tēv"); // nom. pl.
    checkOneTerm(a, "tēva", "tēv"); // gen. sing.
    checkOneTerm(a, "tēvu", "tēv"); // gen. pl.
    checkOneTerm(a, "tēvam", "tēv"); // dat. sing.
    checkOneTerm(a, "tēviem", "tēv"); // dat. pl.
    checkOneTerm(a, "tēvu", "tēv"); // acc. sing.
    checkOneTerm(a, "tēvus", "tēv"); // acc. pl.
    checkOneTerm(a, "tēvā", "tēv"); // loc. sing.
    checkOneTerm(a, "tēvos", "tēv"); // loc. pl.
    checkOneTerm(a, "tēvs", "tēv"); // voc. sing.
    checkOneTerm(a, "tēvi", "tēv"); // voc. pl.
  }

  /**
   * decl II nouns with (s,t) -> š and (d,z) -> ž palatalization will generally conflate to
   * two stems due to the ambiguity (plural and singular).
   */
  public void testNouns2() throws IOException {
    // decl. II

    // c -> č palatalization
    checkOneTerm(a, "lācis", "lāc"); // nom. sing.
    checkOneTerm(a, "lāči", "lāc"); // nom. pl.
    checkOneTerm(a, "lāča", "lāc"); // gen. sing.
    checkOneTerm(a, "lāču", "lāc"); // gen. pl.
    checkOneTerm(a, "lācim", "lāc"); // dat. sing.
    checkOneTerm(a, "lāčiem", "lāc"); // dat. pl.
    checkOneTerm(a, "lāci", "lāc"); // acc. sing.
    checkOneTerm(a, "lāčus", "lāc"); // acc. pl.
    checkOneTerm(a, "lācī", "lāc"); // loc. sing.
    checkOneTerm(a, "lāčos", "lāc"); // loc. pl.
    checkOneTerm(a, "lāci", "lāc"); // voc. sing.
    checkOneTerm(a, "lāči", "lāc"); // voc. pl.

    // n -> ņ palatalization
    checkOneTerm(a, "akmens", "akmen"); // nom. sing.
    checkOneTerm(a, "akmeņi", "akmen"); // nom. pl.
    checkOneTerm(a, "akmens", "akmen"); // gen. sing.
    checkOneTerm(a, "akmeņu", "akmen"); // gen. pl.
    checkOneTerm(a, "akmenim", "akmen"); // dat. sing.
    checkOneTerm(a, "akmeņiem", "akmen"); // dat. pl.
    checkOneTerm(a, "akmeni", "akmen"); // acc. sing.
    checkOneTerm(a, "akmeņus", "akmen"); // acc. pl.
    checkOneTerm(a, "akmenī", "akmen"); // loc. sing.
    checkOneTerm(a, "akmeņos", "akmen"); // loc. pl.
    checkOneTerm(a, "akmens", "akmen"); // voc. sing.
    checkOneTerm(a, "akmeņi", "akmen"); // voc. pl.

    // no palatalization
    checkOneTerm(a, "kurmis", "kurm"); // nom. sing.
    checkOneTerm(a, "kurmji", "kurm"); // nom. pl.
    checkOneTerm(a, "kurmja", "kurm"); // gen. sing.
    checkOneTerm(a, "kurmju", "kurm"); // gen. pl.
    checkOneTerm(a, "kurmim", "kurm"); // dat. sing.
    checkOneTerm(a, "kurmjiem", "kurm"); // dat. pl.
    checkOneTerm(a, "kurmi", "kurm"); // acc. sing.
    checkOneTerm(a, "kurmjus", "kurm"); // acc. pl.
    checkOneTerm(a, "kurmī", "kurm"); // loc. sing.
    checkOneTerm(a, "kurmjos", "kurm"); // loc. pl.
    checkOneTerm(a, "kurmi", "kurm"); // voc. sing.
    checkOneTerm(a, "kurmji", "kurm"); // voc. pl.
  }

  public void testNouns3() throws IOException {
    // decl III
    checkOneTerm(a, "lietus", "liet"); // nom. sing.
    checkOneTerm(a, "lieti", "liet"); // nom. pl.
    checkOneTerm(a, "lietus", "liet"); // gen. sing.
    checkOneTerm(a, "lietu", "liet"); // gen. pl.
    checkOneTerm(a, "lietum", "liet"); // dat. sing.
    checkOneTerm(a, "lietiem", "liet"); // dat. pl.
    checkOneTerm(a, "lietu", "liet"); // acc. sing.
    checkOneTerm(a, "lietus", "liet"); // acc. pl.
    checkOneTerm(a, "lietū", "liet"); // loc. sing.
    checkOneTerm(a, "lietos", "liet"); // loc. pl.
    checkOneTerm(a, "lietus", "liet"); // voc. sing.
    checkOneTerm(a, "lieti", "liet"); // voc. pl.
  }

  public void testNouns4() throws IOException {
    // decl IV
    checkOneTerm(a, "lapa", "lap"); // nom. sing.
    checkOneTerm(a, "lapas", "lap"); // nom. pl.
    checkOneTerm(a, "lapas", "lap"); // gen. sing.
    checkOneTerm(a, "lapu", "lap"); // gen. pl.
    checkOneTerm(a, "lapai", "lap"); // dat. sing.
    checkOneTerm(a, "lapām", "lap"); // dat. pl.
    checkOneTerm(a, "lapu", "lap"); // acc. sing.
    checkOneTerm(a, "lapas", "lap"); // acc. pl.
    checkOneTerm(a, "lapā", "lap"); // loc. sing.
    checkOneTerm(a, "lapās", "lap"); // loc. pl.
    checkOneTerm(a, "lapa", "lap"); // voc. sing.
    checkOneTerm(a, "lapas", "lap"); // voc. pl.

    checkOneTerm(a, "puika", "puik"); // nom. sing.
    checkOneTerm(a, "puikas", "puik"); // nom. pl.
    checkOneTerm(a, "puikas", "puik"); // gen. sing.
    checkOneTerm(a, "puiku", "puik"); // gen. pl.
    checkOneTerm(a, "puikam", "puik"); // dat. sing.
    checkOneTerm(a, "puikām", "puik"); // dat. pl.
    checkOneTerm(a, "puiku", "puik"); // acc. sing.
    checkOneTerm(a, "puikas", "puik"); // acc. pl.
    checkOneTerm(a, "puikā", "puik"); // loc. sing.
    checkOneTerm(a, "puikās", "puik"); // loc. pl.
    checkOneTerm(a, "puika", "puik"); // voc. sing.
    checkOneTerm(a, "puikas", "puik"); // voc. pl.
  }

  /**
   * Genitive plural forms with (s,t) -> š and (d,z) -> ž will not conflate due to ambiguity.
   */
  public void testNouns5() throws IOException {
    // decl V
    // l -> ļ palatalization
    checkOneTerm(a, "egle", "egl"); // nom. sing.
    checkOneTerm(a, "egles", "egl"); // nom. pl.
    checkOneTerm(a, "egles", "egl"); // gen. sing.
    checkOneTerm(a, "egļu", "egl"); // gen. pl.
    checkOneTerm(a, "eglei", "egl"); // dat. sing.
    checkOneTerm(a, "eglēm", "egl"); // dat. pl.
    checkOneTerm(a, "egli", "egl"); // acc. sing.
    checkOneTerm(a, "egles", "egl"); // acc. pl.
    checkOneTerm(a, "eglē", "egl"); // loc. sing.
    checkOneTerm(a, "eglēs", "egl"); // loc. pl.
    checkOneTerm(a, "egle", "egl"); // voc. sing.
    checkOneTerm(a, "egles", "egl"); // voc. pl.
  }

  public void testNouns6() throws IOException {
    // decl VI

    // no palatalization
    checkOneTerm(a, "govs", "gov"); // nom. sing.
    checkOneTerm(a, "govis", "gov"); // nom. pl.
    checkOneTerm(a, "govs", "gov"); // gen. sing.
    checkOneTerm(a, "govju", "gov"); // gen. pl.
    checkOneTerm(a, "govij", "gov"); // dat. sing.
    checkOneTerm(a, "govīm", "gov"); // dat. pl.
    checkOneTerm(a, "govi ", "gov"); // acc. sing.
    checkOneTerm(a, "govis", "gov"); // acc. pl.
    checkOneTerm(a, "govi ", "gov"); // inst. sing.
    checkOneTerm(a, "govīm", "gov"); // inst. pl.
    checkOneTerm(a, "govī", "gov"); // loc. sing.
    checkOneTerm(a, "govīs", "gov"); // loc. pl.
    checkOneTerm(a, "govs", "gov"); // voc. sing.
    checkOneTerm(a, "govis", "gov"); // voc. pl.
  }

  public void testAdjectives() throws IOException {
    checkOneTerm(a, "zils", "zil"); // indef. nom. masc. sing.
    checkOneTerm(a, "zilais", "zil"); // def. nom. masc. sing.
    checkOneTerm(a, "zili", "zil"); // indef. nom. masc. pl.
    checkOneTerm(a, "zilie", "zil"); // def. nom. masc. pl.
    checkOneTerm(a, "zila", "zil"); // indef. nom. fem. sing.
    checkOneTerm(a, "zilā", "zil"); // def. nom. fem. sing.
    checkOneTerm(a, "zilas", "zil"); // indef. nom. fem. pl.
    checkOneTerm(a, "zilās", "zil"); // def. nom. fem. pl.
    checkOneTerm(a, "zila", "zil"); // indef. gen. masc. sing.
    checkOneTerm(a, "zilā", "zil"); // def. gen. masc. sing.
    checkOneTerm(a, "zilu", "zil"); // indef. gen. masc. pl.
    checkOneTerm(a, "zilo", "zil"); // def. gen. masc. pl.
    checkOneTerm(a, "zilas", "zil"); // indef. gen. fem. sing.
    checkOneTerm(a, "zilās", "zil"); // def. gen. fem. sing.
    checkOneTerm(a, "zilu", "zil"); // indef. gen. fem. pl.
    checkOneTerm(a, "zilo", "zil"); // def. gen. fem. pl.
    checkOneTerm(a, "zilam", "zil"); // indef. dat. masc. sing.
    checkOneTerm(a, "zilajam", "zil"); // def. dat. masc. sing.
    checkOneTerm(a, "ziliem", "zil"); // indef. dat. masc. pl.
    checkOneTerm(a, "zilajiem", "zil"); // def. dat. masc. pl.
    checkOneTerm(a, "zilai", "zil"); // indef. dat. fem. sing.
    checkOneTerm(a, "zilajai", "zil"); // def. dat. fem. sing.
    checkOneTerm(a, "zilām", "zil"); // indef. dat. fem. pl.
    checkOneTerm(a, "zilajām", "zil"); // def. dat. fem. pl.
    checkOneTerm(a, "zilu", "zil"); // indef. acc. masc. sing.
    checkOneTerm(a, "zilo", "zil"); // def. acc. masc. sing.
    checkOneTerm(a, "zilus", "zil"); // indef. acc. masc. pl.
    checkOneTerm(a, "zilos", "zil"); // def. acc. masc. pl.
    checkOneTerm(a, "zilu", "zil"); // indef. acc. fem. sing.
    checkOneTerm(a, "zilo", "zil"); // def. acc. fem. sing.
    checkOneTerm(a, "zilās", "zil"); // indef. acc. fem. pl.
    checkOneTerm(a, "zilās", "zil"); // def. acc. fem. pl.
    checkOneTerm(a, "zilā", "zil"); // indef. loc. masc. sing.
    checkOneTerm(a, "zilajā", "zil"); // def. loc. masc. sing.
    checkOneTerm(a, "zilos", "zil"); // indef. loc. masc. pl.
    checkOneTerm(a, "zilajos", "zil"); // def. loc. masc. pl.
    checkOneTerm(a, "zilā", "zil"); // indef. loc. fem. sing.
    checkOneTerm(a, "zilajā", "zil"); // def. loc. fem. sing.
    checkOneTerm(a, "zilās", "zil"); // indef. loc. fem. pl.
    checkOneTerm(a, "zilajās", "zil"); // def. loc. fem. pl.
    checkOneTerm(a, "zilais", "zil"); // voc. masc. sing.
    checkOneTerm(a, "zilie", "zil"); // voc. masc. pl.
    checkOneTerm(a, "zilā", "zil"); // voc. fem. sing.
    checkOneTerm(a, "zilās", "zil"); // voc. fem. pl.
  }

  /** Note: we intentionally don't handle the ambiguous (s,t) -> š and (d,z) -> ž */
  public void testPalatalization() throws IOException {
    checkOneTerm(a, "krāsns", "krāsn"); // nom. sing.
    checkOneTerm(a, "krāšņu", "krāsn"); // gen. pl.
    checkOneTerm(a, "zvaigzne", "zvaigzn"); // nom. sing.
    checkOneTerm(a, "zvaigžņu", "zvaigzn"); // gen. pl.
    checkOneTerm(a, "kāpslis", "kāpsl"); // nom. sing.
    checkOneTerm(a, "kāpšļu", "kāpsl"); // gen. pl.
    checkOneTerm(a, "zizlis", "zizl"); // nom. sing.
    checkOneTerm(a, "zižļu", "zizl"); // gen. pl.
    checkOneTerm(a, "vilnis", "viln"); // nom. sing.
    checkOneTerm(a, "viļņu", "viln"); // gen. pl.
    checkOneTerm(a, "lelle", "lell"); // nom. sing.
    checkOneTerm(a, "leļļu", "lell"); // gen. pl.
    checkOneTerm(a, "pinne", "pinn"); // nom. sing.
    checkOneTerm(a, "piņņu", "pinn"); // gen. pl.
    checkOneTerm(a, "rīkste", "rīkst"); // nom. sing.
    checkOneTerm(a, "rīkšu", "rīkst"); // gen. pl.
  }

  /** Test some length restrictions, we require a 3+ char stem, with at least one vowel. */
  public void testLength() throws IOException {
    checkOneTerm(a, "usa", "usa"); // length
    checkOneTerm(a, "60ms", "60ms"); // vowel count
  }

  public void testEmptyTerm() throws IOException {
    Analyzer a =
        new Analyzer() {
          @Override
          protected TokenStreamComponents createComponents(String fieldName) {
            Tokenizer tokenizer = new KeywordTokenizer();
            return new TokenStreamComponents(tokenizer, new LatvianStemFilter(tokenizer));
          }
        };
    checkOneTerm(a, "", "");
    a.close();
  }
}