001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.codec.language.bm; 019 020import java.util.ArrayList; 021import java.util.Arrays; 022import java.util.Collections; 023import java.util.EnumMap; 024import java.util.HashSet; 025import java.util.LinkedHashSet; 026import java.util.List; 027import java.util.Locale; 028import java.util.Map; 029import java.util.Objects; 030import java.util.Set; 031import java.util.TreeMap; 032import java.util.stream.Collectors; 033 034import org.apache.commons.codec.language.bm.Languages.LanguageSet; 035import org.apache.commons.codec.language.bm.Rule.Phoneme; 036 037/** 038 * Converts words into potential phonetic representations. 039 * <p> 040 * This is a two-stage process. Firstly, the word is converted into a phonetic representation that takes 041 * into account the likely source language. Next, this phonetic representation is converted into a 042 * pan-European 'average' representation, allowing comparison between different versions of essentially 043 * the same word from different languages. 044 * </p> 045 * <p> 046 * This class is intentionally immutable and thread-safe. 047 * If you wish to alter the settings for a PhoneticEngine, you 048 * must make a new one with the updated settings. 049 * </p> 050 * <p> 051 * Ported from phoneticengine.php 052 * </p> 053 * 054 * @since 1.6 055 */ 056public class PhoneticEngine { 057 058 private static final int DEFAULT_MAX_PHONEMES = 20; 059 060 private static final Map<NameType, Set<String>> NAME_PREFIXES = new EnumMap<>(NameType.class); 061 062 private final Lang lang; 063 064 private final NameType nameType; 065 066 private final RuleType ruleType; 067 068 private final boolean concat; 069 070 private final int maxPhonemes; 071 072 static { 073 NAME_PREFIXES.put(NameType.ASHKENAZI, 074 Collections.unmodifiableSet( 075 new HashSet<>(Arrays.asList("bar", "ben", "da", "de", "van", "von")))); 076 NAME_PREFIXES.put(NameType.SEPHARDIC, 077 Collections.unmodifiableSet( 078 new HashSet<>(Arrays.asList("al", "el", "da", "dal", "de", "del", "dela", "de la", 079 "della", "des", "di", "do", "dos", "du", "van", "von")))); 080 NAME_PREFIXES.put(NameType.GENERIC, 081 Collections.unmodifiableSet( 082 new HashSet<>(Arrays.asList("da", "dal", "de", "del", "dela", "de la", "della", 083 "des", "di", "do", "dos", "du", "van", "von")))); 084 } 085 086 /** 087 * Utility for manipulating a set of phonemes as they are being built up. Not intended for use outside 088 * this package, and probably not outside the {@link PhoneticEngine} class. 089 * 090 * @since 1.6 091 */ 092 static final class PhonemeBuilder { 093 094 private final Set<Rule.Phoneme> phonemes; 095 096 /** 097 * An empty builder where all phonemes must come from some set of languages. This will contain a single 098 * phoneme of zero characters. This can then be appended to. This should be the only way to create a new 099 * phoneme from scratch. 100 * 101 * @param languages the set of languages 102 * @return a new, empty phoneme builder 103 */ 104 public static PhonemeBuilder empty(final Languages.LanguageSet languages) { 105 return new PhonemeBuilder(new Rule.Phoneme("", languages)); 106 } 107 108 private PhonemeBuilder(final Rule.Phoneme phoneme) { 109 this.phonemes = new LinkedHashSet<>(); 110 this.phonemes.add(phoneme); 111 } 112 113 private PhonemeBuilder(final Set<Rule.Phoneme> phonemes) { 114 this.phonemes = phonemes; 115 } 116 117 /** 118 * Creates a new phoneme builder containing all phonemes in this one extended by {@code str}. 119 * 120 * @param str the characters to append to the phonemes 121 */ 122 public void append(final CharSequence str) { 123 phonemes.forEach(ph -> ph.append(str)); 124 } 125 126 /** 127 * Applies the given phoneme expression to all phonemes in this phoneme builder. 128 * <p> 129 * This will lengthen phonemes that have compatible language sets to the expression, and drop those that are 130 * incompatible. 131 * </p> 132 * 133 * @param phonemeExpr the expression to apply 134 * @param maxPhonemes the maximum number of phonemes to build up 135 */ 136 public void apply(final Rule.PhonemeExpr phonemeExpr, final int maxPhonemes) { 137 final Set<Rule.Phoneme> newPhonemes = new LinkedHashSet<>(maxPhonemes); 138 139 EXPR: for (final Rule.Phoneme left : this.phonemes) { 140 for (final Rule.Phoneme right : phonemeExpr.getPhonemes()) { 141 final LanguageSet languages = left.getLanguages().restrictTo(right.getLanguages()); 142 if (!languages.isEmpty()) { 143 final Rule.Phoneme join = new Phoneme(left, right, languages); 144 if (newPhonemes.size() < maxPhonemes) { 145 newPhonemes.add(join); 146 if (newPhonemes.size() >= maxPhonemes) { 147 break EXPR; 148 } 149 } 150 } 151 } 152 } 153 154 this.phonemes.clear(); 155 this.phonemes.addAll(newPhonemes); 156 } 157 158 /** 159 * Gets underlying phoneme set. Please don't mutate. 160 * 161 * @return the phoneme set 162 */ 163 public Set<Rule.Phoneme> getPhonemes() { 164 return this.phonemes; 165 } 166 167 /** 168 * Stringifies the phoneme set. This produces a single string of the strings of each phoneme, 169 * joined with a pipe. This is explicitly provided in place of toString as it is a potentially 170 * expensive operation, which should be avoided when debugging. 171 * 172 * @return the stringified phoneme set 173 */ 174 public String makeString() { 175 return phonemes.stream().map(Rule.Phoneme::getPhonemeText).collect(Collectors.joining("|")); 176 } 177 } 178 179 /** 180 * A function closure capturing the application of a list of rules to an input sequence at a particular offset. 181 * After invocation, the values {@code i} and {@code found} are updated. {@code i} points to the 182 * index of the next char in {@code input} that must be processed next (the input up to that index having been 183 * processed already), and {@code found} indicates if a matching rule was found or not. In the case where a 184 * matching rule was found, {@code phonemeBuilder} is replaced with a new builder containing the phonemes 185 * updated by the matching rule. 186 * 187 * Although this class is not thread-safe (it has mutable unprotected fields), it is not shared between threads 188 * as it is constructed as needed by the calling methods. 189 * @since 1.6 190 */ 191 private static final class RulesApplication { 192 private final Map<String, List<Rule>> finalRules; 193 private final CharSequence input; 194 195 private final PhonemeBuilder phonemeBuilder; 196 private int i; 197 private final int maxPhonemes; 198 private boolean found; 199 200 public RulesApplication(final Map<String, List<Rule>> finalRules, final CharSequence input, 201 final PhonemeBuilder phonemeBuilder, final int i, final int maxPhonemes) { 202 Objects.requireNonNull(finalRules, "finalRules"); 203 this.finalRules = finalRules; 204 this.phonemeBuilder = phonemeBuilder; 205 this.input = input; 206 this.i = i; 207 this.maxPhonemes = maxPhonemes; 208 } 209 210 public int getI() { 211 return this.i; 212 } 213 214 public PhonemeBuilder getPhonemeBuilder() { 215 return this.phonemeBuilder; 216 } 217 218 /** 219 * Invokes the rules. Loops over the rules list, stopping at the first one that has a matching context 220 * and pattern. Then applies this rule to the phoneme builder to produce updated phonemes. If there was no 221 * match, {@code i} is advanced one and the character is silently dropped from the phonetic spelling. 222 * 223 * @return {@code this} 224 */ 225 public RulesApplication invoke() { 226 this.found = false; 227 int patternLength = 1; 228 final List<Rule> rules = this.finalRules.get(input.subSequence(i, i+patternLength)); 229 if (rules != null) { 230 for (final Rule rule : rules) { 231 final String pattern = rule.getPattern(); 232 patternLength = pattern.length(); 233 if (rule.patternAndContextMatches(this.input, this.i)) { 234 this.phonemeBuilder.apply(rule.getPhoneme(), maxPhonemes); 235 this.found = true; 236 break; 237 } 238 } 239 } 240 241 if (!this.found) { 242 patternLength = 1; 243 } 244 245 this.i += patternLength; 246 return this; 247 } 248 249 public boolean isFound() { 250 return this.found; 251 } 252 } 253 254 /** 255 * Joins some strings with an internal separator. 256 * 257 * @param strings Strings to join 258 * @param sep String to separate them with 259 * @return a single String consisting of each element of {@code strings} interleaved by {@code sep} 260 */ 261 private static String join(final List<String> strings, final String sep) { 262 return strings.stream().collect(Collectors.joining(sep)); 263 } 264 265 /** 266 * Generates a new, fully-configured phonetic engine. 267 * 268 * @param nameType 269 * the type of names it will use 270 * @param ruleType 271 * the type of rules it will apply 272 * @param concat 273 * if it will concatenate multiple encodings 274 */ 275 public PhoneticEngine(final NameType nameType, final RuleType ruleType, final boolean concat) { 276 this(nameType, ruleType, concat, DEFAULT_MAX_PHONEMES); 277 } 278 279 /** 280 * Generates a new, fully-configured phonetic engine. 281 * 282 * @param nameType 283 * the type of names it will use 284 * @param ruleType 285 * the type of rules it will apply 286 * @param concat 287 * if it will concatenate multiple encodings 288 * @param maxPhonemes 289 * the maximum number of phonemes that will be handled 290 * @since 1.7 291 */ 292 public PhoneticEngine(final NameType nameType, final RuleType ruleType, final boolean concat, 293 final int maxPhonemes) { 294 if (ruleType == RuleType.RULES) { 295 throw new IllegalArgumentException("ruleType must not be " + RuleType.RULES); 296 } 297 this.nameType = nameType; 298 this.ruleType = ruleType; 299 this.concat = concat; 300 this.lang = Lang.instance(nameType); 301 this.maxPhonemes = maxPhonemes; 302 } 303 304 /** 305 * Applies the final rules to convert from a language-specific phonetic representation to a 306 * language-independent representation. 307 * 308 * @param phonemeBuilder the current phonemes 309 * @param finalRules the final rules to apply 310 * @return the resulting phonemes 311 */ 312 private PhonemeBuilder applyFinalRules(final PhonemeBuilder phonemeBuilder, 313 final Map<String, List<Rule>> finalRules) { 314 Objects.requireNonNull(finalRules, "finalRules"); 315 if (finalRules.isEmpty()) { 316 return phonemeBuilder; 317 } 318 319 final Map<Rule.Phoneme, Rule.Phoneme> phonemes = new TreeMap<>(Rule.Phoneme.COMPARATOR); 320 321 phonemeBuilder.getPhonemes().forEach(phoneme -> { 322 PhonemeBuilder subBuilder = PhonemeBuilder.empty(phoneme.getLanguages()); 323 final String phonemeText = phoneme.getPhonemeText().toString(); 324 325 for (int i = 0; i < phonemeText.length();) { 326 final RulesApplication rulesApplication = new RulesApplication(finalRules, phonemeText, subBuilder, i, maxPhonemes).invoke(); 327 final boolean found = rulesApplication.isFound(); 328 subBuilder = rulesApplication.getPhonemeBuilder(); 329 330 if (!found) { 331 // not found, appending as-is 332 subBuilder.append(phonemeText.subSequence(i, i + 1)); 333 } 334 335 i = rulesApplication.getI(); 336 } 337 338 // the phonemes map orders the phonemes only based on their text, but ignores the language set 339 // when adding new phonemes, check for equal phonemes and merge their language set, otherwise 340 // phonemes with the same text but different language set get lost 341 subBuilder.getPhonemes().forEach(newPhoneme -> { 342 if (phonemes.containsKey(newPhoneme)) { 343 final Rule.Phoneme oldPhoneme = phonemes.remove(newPhoneme); 344 final Rule.Phoneme mergedPhoneme = oldPhoneme.mergeWithLanguage(newPhoneme.getLanguages()); 345 phonemes.put(mergedPhoneme, mergedPhoneme); 346 } else { 347 phonemes.put(newPhoneme, newPhoneme); 348 } 349 }); 350 }); 351 352 return new PhonemeBuilder(phonemes.keySet()); 353 } 354 355 /** 356 * Encodes a string to its phonetic representation. 357 * 358 * @param input 359 * the String to encode 360 * @return the encoding of the input 361 */ 362 public String encode(final String input) { 363 final Languages.LanguageSet languageSet = this.lang.guessLanguages(input); 364 return encode(input, languageSet); 365 } 366 367 /** 368 * Encodes an input string into an output phonetic representation, given a set of possible origin languages. 369 * 370 * @param input 371 * String to phoneticise; a String with dashes or spaces separating each word 372 * @param languageSet 373 * set of possible origin languages 374 * @return a phonetic representation of the input; a String containing '-'-separated phonetic representations of the 375 * input 376 */ 377 public String encode(String input, final Languages.LanguageSet languageSet) { 378 final Map<String, List<Rule>> rules = Rule.getInstanceMap(this.nameType, RuleType.RULES, languageSet); 379 // rules common across many (all) languages 380 final Map<String, List<Rule>> finalRules1 = Rule.getInstanceMap(this.nameType, this.ruleType, "common"); 381 // rules that apply to a specific language that may be ambiguous or wrong if applied to other languages 382 final Map<String, List<Rule>> finalRules2 = Rule.getInstanceMap(this.nameType, this.ruleType, languageSet); 383 384 // tidy the input 385 // lower case is a locale-dependent operation 386 input = input.toLowerCase(Locale.ENGLISH).replace('-', ' ').trim(); 387 388 if (this.nameType == NameType.GENERIC) { 389 if (input.startsWith("d'")) { // check for d' 390 final String remainder = input.substring(2); 391 final String combined = "d" + remainder; 392 return "(" + encode(remainder) + ")-(" + encode(combined) + ")"; 393 } 394 for (final String l : NAME_PREFIXES.get(this.nameType)) { 395 // handle generic prefixes 396 if (input.startsWith(l + " ")) { 397 // check for any prefix in the words list 398 final String remainder = input.substring(l.length() + 1); // input without the prefix 399 final String combined = l + remainder; // input with prefix without space 400 return "(" + encode(remainder) + ")-(" + encode(combined) + ")"; 401 } 402 } 403 } 404 405 final List<String> words = Arrays.asList(input.split("\\s+")); 406 final List<String> words2 = new ArrayList<>(); 407 408 // special-case handling of word prefixes based upon the name type 409 switch (this.nameType) { 410 case SEPHARDIC: 411 words.forEach(aWord -> { 412 final String[] parts = aWord.split("'"); 413 words2.add(parts[parts.length - 1]); 414 }); 415 words2.removeAll(NAME_PREFIXES.get(this.nameType)); 416 break; 417 case ASHKENAZI: 418 words2.addAll(words); 419 words2.removeAll(NAME_PREFIXES.get(this.nameType)); 420 break; 421 case GENERIC: 422 words2.addAll(words); 423 break; 424 default: 425 throw new IllegalStateException("Unreachable case: " + this.nameType); 426 } 427 428 if (this.concat) { 429 // concat mode enabled 430 input = join(words2, " "); 431 } else if (words2.size() == 1) { 432 // not a multi-word name 433 input = words.iterator().next(); 434 } else { 435 // encode each word in a multi-word name separately (normally used for approx matches) 436 final StringBuilder result = new StringBuilder(); 437 words2.forEach(word -> result.append("-").append(encode(word))); 438 // return the result without the leading "-" 439 return result.substring(1); 440 } 441 442 PhonemeBuilder phonemeBuilder = PhonemeBuilder.empty(languageSet); 443 444 // loop over each char in the input - we will handle the increment manually 445 for (int i = 0; i < input.length();) { 446 final RulesApplication rulesApplication = 447 new RulesApplication(rules, input, phonemeBuilder, i, maxPhonemes).invoke(); 448 i = rulesApplication.getI(); 449 phonemeBuilder = rulesApplication.getPhonemeBuilder(); 450 } 451 452 // Apply the general rules 453 phonemeBuilder = applyFinalRules(phonemeBuilder, finalRules1); 454 // Apply the language-specific rules 455 phonemeBuilder = applyFinalRules(phonemeBuilder, finalRules2); 456 457 return phonemeBuilder.makeString(); 458 } 459 460 /** 461 * Gets the Lang language guessing rules being used. 462 * 463 * @return the Lang in use 464 */ 465 public Lang getLang() { 466 return this.lang; 467 } 468 469 /** 470 * Gets the NameType being used. 471 * 472 * @return the NameType in use 473 */ 474 public NameType getNameType() { 475 return this.nameType; 476 } 477 478 /** 479 * Gets the RuleType being used. 480 * 481 * @return the RuleType in use 482 */ 483 public RuleType getRuleType() { 484 return this.ruleType; 485 } 486 487 /** 488 * Gets if multiple phonetic encodings are concatenated or if just the first one is kept. 489 * 490 * @return true if multiple phonetic encodings are returned, false if just the first is 491 */ 492 public boolean isConcat() { 493 return this.concat; 494 } 495 496 /** 497 * Gets the maximum number of phonemes the engine will calculate for a given input. 498 * 499 * @return the maximum number of phonemes 500 * @since 1.7 501 */ 502 public int getMaxPhonemes() { 503 return this.maxPhonemes; 504 } 505}