1 package org.apache.lucene.analysis.icu.segmentation;
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20 import java.io.IOException;
21 import java.io.InputStream;
23 import org.apache.lucene.analysis.standard.StandardTokenizer;
25 import com.ibm.icu.lang.UScript;
26 import com.ibm.icu.text.BreakIterator;
27 import com.ibm.icu.text.RuleBasedBreakIterator;
28 import com.ibm.icu.util.ULocale;
31 * Default {@link ICUTokenizerConfig} that is generally applicable
34 * Generally tokenizes Unicode text according to UAX#29
35 * ({@link BreakIterator#getWordInstance(ULocale) BreakIterator.getWordInstance(ULocale.ROOT)}),
36 * but with the following tailorings:
38 * <li>Thai text is broken into words with a
39 * {@link com.ibm.icu.text.DictionaryBasedBreakIterator}
40 * <li>Lao, Myanmar, and Khmer text is broken into syllables
41 * based on custom BreakIterator rules.
42 * <li>Hebrew text has custom tailorings to handle special cases
43 * involving punctuation.
45 * @lucene.experimental
47 public class DefaultICUTokenizerConfig extends ICUTokenizerConfig {
48 /** Token type for words containing ideographic characters */
49 public static final String WORD_IDEO = StandardTokenizer.TOKEN_TYPES[StandardTokenizer.IDEOGRAPHIC];
50 /** Token type for words containing Japanese hiragana */
51 public static final String WORD_HIRAGANA = StandardTokenizer.TOKEN_TYPES[StandardTokenizer.HIRAGANA];
52 /** Token type for words containing Japanese katakana */
53 public static final String WORD_KATAKANA = StandardTokenizer.TOKEN_TYPES[StandardTokenizer.KATAKANA];
54 /** Token type for words containing Korean hangul */
55 public static final String WORD_HANGUL = StandardTokenizer.TOKEN_TYPES[StandardTokenizer.HANGUL];
56 /** Token type for words that contain letters */
57 public static final String WORD_LETTER = StandardTokenizer.TOKEN_TYPES[StandardTokenizer.ALPHANUM];
58 /** Token type for words that appear to be numbers */
59 public static final String WORD_NUMBER = StandardTokenizer.TOKEN_TYPES[StandardTokenizer.NUM];
62 * the default breakiterators in use. these can be expensive to
63 * instantiate, cheap to clone.
65 private static final BreakIterator rootBreakIterator =
66 readBreakIterator("Default.brk");
67 private static final BreakIterator thaiBreakIterator =
68 BreakIterator.getWordInstance(new ULocale("th_TH"));
69 private static final BreakIterator hebrewBreakIterator =
70 readBreakIterator("Hebrew.brk");
71 private static final BreakIterator khmerBreakIterator =
72 readBreakIterator("Khmer.brk");
73 private static final BreakIterator laoBreakIterator =
74 new LaoBreakIterator(readBreakIterator("Lao.brk"));
75 private static final BreakIterator myanmarBreakIterator =
76 readBreakIterator("Myanmar.brk");
79 public BreakIterator getBreakIterator(int script) {
81 case UScript.THAI: return (BreakIterator)thaiBreakIterator.clone();
82 case UScript.HEBREW: return (BreakIterator)hebrewBreakIterator.clone();
83 case UScript.KHMER: return (BreakIterator)khmerBreakIterator.clone();
84 case UScript.LAO: return (BreakIterator)laoBreakIterator.clone();
85 case UScript.MYANMAR: return (BreakIterator)myanmarBreakIterator.clone();
86 default: return (BreakIterator)rootBreakIterator.clone();
91 public String getType(int script, int ruleStatus) {
93 case RuleBasedBreakIterator.WORD_IDEO:
95 case RuleBasedBreakIterator.WORD_KANA:
96 return script == UScript.HIRAGANA ? WORD_HIRAGANA : WORD_KATAKANA;
97 case RuleBasedBreakIterator.WORD_LETTER:
98 return script == UScript.HANGUL ? WORD_HANGUL : WORD_LETTER;
99 case RuleBasedBreakIterator.WORD_NUMBER:
101 default: /* some other custom code */
106 private static RuleBasedBreakIterator readBreakIterator(String filename) {
108 DefaultICUTokenizerConfig.class.getResourceAsStream(filename);
110 RuleBasedBreakIterator bi =
111 RuleBasedBreakIterator.getInstanceFromCompiledRules(is);
114 } catch (IOException e) {
115 throw new RuntimeException(e);