1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.codec.language.bm;
19
20 import org.apache.commons.codec.EncoderException;
21 import org.apache.commons.codec.StringEncoder;
22
23 /**
24 * Encodes strings into their Beider-Morse phonetic encoding.
25 * <p>
26 * Beider-Morse phonetic encodings are optimised for family names. However, they may be useful for a wide range of
27 * words.
28 * <p>
29 * This encoder is intentionally mutable to allow dynamic configuration through bean properties. As such, it is mutable,
30 * and may not be thread-safe. If you require a guaranteed thread-safe encoding then use {@link PhoneticEngine}
31 * directly.
32 * <p>
33 * <b>Encoding overview</b>
34 * <p>
35 * Beider-Morse phonetic encodings is a multi-step process. Firstly, a table of rules is consulted to guess what
36 * language the word comes from. For example, if it ends in "<code>ault</code>" then it infers that the word is French.
37 * Next, the word is translated into a phonetic representation using a language-specific phonetics table. Some runs of
38 * letters can be pronounced in multiple ways, and a single run of letters may be potentially broken up into phonemes at
39 * different places, so this stage results in a set of possible language-specific phonetic representations. Lastly, this
40 * language-specific phonetic representation is processed by a table of rules that re-writes it phonetically taking into
41 * account systematic pronunciation differences between languages, to move it towards a pan-indo-european phonetic
42 * representation. Again, sometimes there are multiple ways this could be done and sometimes things that can be
43 * pronounced in several ways in the source language have only one way to represent them in this average phonetic
44 * language, so the result is again a set of phonetic spellings.
45 * <p>
46 * Some names are treated as having multiple parts. This can be due to two things. Firstly, they may be hyphenated. In
47 * this case, each individual hyphenated word is encoded, and then these are combined end-to-end for the final encoding.
48 * Secondly, some names have standard prefixes, for example, "<code>Mac/Mc</code>" in Scottish (English) names. As
49 * sometimes it is ambiguous whether the prefix is intended or is an accident of the spelling, the word is encoded once
50 * with the prefix and once without it. The resulting encoding contains one and then the other result.
51 * <p>
52 * <b>Encoding format</b>
53 * <p>
54 * Individual phonetic spellings of an input word are represented in upper- and lower-case roman characters. Where there
55 * are multiple possible phonetic representations, these are joined with a pipe (<code>|</code>) character. If multiple
56 * hyphenated words where found, or if the word may contain a name prefix, each encoded word is placed in elipses and
57 * these blocks are then joined with hyphens. For example, "<code>d'ortley</code>" has a possible prefix. The form
58 * without prefix encodes to "<code>ortlaj|ortlej</code>", while the form with prefix encodes to "
59 * <code>dortlaj|dortlej</code>". Thus, the full, combined encoding is "<code>(ortlaj|ortlej)-(dortlaj|dortlej)</code>".
60 * <p>
61 * The encoded forms are often quite a bit longer than the input strings. This is because a single input may have many
62 * potential phonetic interpretations. For example, "<code>Renault</code>" encodes to "
63 * <code>rYnDlt|rYnalt|rYnult|rinDlt|rinalt|rinult</code>". The <code>APPROX</code> rules will tend to produce larger
64 * encodings as they consider a wider range of possible, approximate phonetic interpretations of the original word.
65 * Down-stream applications may wish to further process the encoding for indexing or lookup purposes, for example, by
66 * splitting on pipe (<code>|</code>) and indexing under each of these alternatives.
67 * <p>
68 * <b>Note</b>: this version of the Beider-Morse encoding is equivalent with v3.4 of the reference implementation.
69 *
70 * @see <a href="http://stevemorse.org/phonetics/bmpm.htm">Beider-Morse Phonetic Matching</a>
71 * @see <a href="http://stevemorse.org/phoneticinfo.htm">Reference implementation</a>
72 *
73 * @since 1.6
74 * @version $Id: BeiderMorseEncoder.html 928559 2014-11-10 02:53:54Z ggregory $
75 */
76 public class BeiderMorseEncoder implements StringEncoder {
77 // Implementation note: This class is a spring-friendly facade to PhoneticEngine. It allows read/write configuration
78 // of an immutable PhoneticEngine instance that will be delegated to for the actual encoding.
79
80 // a cached object
81 private PhoneticEngine engine = new PhoneticEngine(NameType.GENERIC, RuleType.APPROX, true);
82
83 @Override
84 public Object encode(final Object source) throws EncoderException {
85 if (!(source instanceof String)) {
86 throw new EncoderException("BeiderMorseEncoder encode parameter is not of type String");
87 }
88 return encode((String) source);
89 }
90
91 @Override
92 public String encode(final String source) throws EncoderException {
93 if (source == null) {
94 return null;
95 }
96 return this.engine.encode(source);
97 }
98
99 /**
100 * Gets the name type currently in operation.
101 *
102 * @return the NameType currently being used
103 */
104 public NameType getNameType() {
105 return this.engine.getNameType();
106 }
107
108 /**
109 * Gets the rule type currently in operation.
110 *
111 * @return the RuleType currently being used
112 */
113 public RuleType getRuleType() {
114 return this.engine.getRuleType();
115 }
116
117 /**
118 * Discovers if multiple possible encodings are concatenated.
119 *
120 * @return true if multiple encodings are concatenated, false if just the first one is returned
121 */
122 public boolean isConcat() {
123 return this.engine.isConcat();
124 }
125
126 /**
127 * Sets how multiple possible phonetic encodings are combined.
128 *
129 * @param concat
130 * true if multiple encodings are to be combined with a '|', false if just the first one is
131 * to be considered
132 */
133 public void setConcat(final boolean concat) {
134 this.engine = new PhoneticEngine(this.engine.getNameType(),
135 this.engine.getRuleType(),
136 concat,
137 this.engine.getMaxPhonemes());
138 }
139
140 /**
141 * Sets the type of name. Use {@link NameType#GENERIC} unless you specifically want phonetic encodings
142 * optimized for Ashkenazi or Sephardic Jewish family names.
143 *
144 * @param nameType
145 * the NameType in use
146 */
147 public void setNameType(final NameType nameType) {
148 this.engine = new PhoneticEngine(nameType,
149 this.engine.getRuleType(),
150 this.engine.isConcat(),
151 this.engine.getMaxPhonemes());
152 }
153
154 /**
155 * Sets the rule type to apply. This will widen or narrow the range of phonetic encodings considered.
156 *
157 * @param ruleType
158 * {@link RuleType#APPROX} or {@link RuleType#EXACT} for approximate or exact phonetic matches
159 */
160 public void setRuleType(final RuleType ruleType) {
161 this.engine = new PhoneticEngine(this.engine.getNameType(),
162 ruleType,
163 this.engine.isConcat(),
164 this.engine.getMaxPhonemes());
165 }
166
167 /**
168 * Sets the number of maximum of phonemes that shall be considered by the engine.
169 *
170 * @param maxPhonemes
171 * the maximum number of phonemes returned by the engine
172 * @since 1.7
173 */
174 public void setMaxPhonemes(final int maxPhonemes) {
175 this.engine = new PhoneticEngine(this.engine.getNameType(),
176 this.engine.getRuleType(),
177 this.engine.isConcat(),
178 maxPhonemes);
179 }
180
181 }