BeiderMorseEncoder.java
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* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
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*
* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.codec.language.bm;
import org.apache.commons.codec.EncoderException;
import org.apache.commons.codec.StringEncoder;
/**
* Encodes strings into their Beider-Morse phonetic encoding.
* <p>
* Beider-Morse phonetic encodings are optimized for family names. However, they may be useful for a wide range of
* words.
* </p>
* <p>
* This encoder is intentionally mutable to allow dynamic configuration through bean properties. As such, it is mutable,
* and may not be thread-safe. If you require a guaranteed thread-safe encoding then use {@link PhoneticEngine}
* directly.
* </p>
* <h2>Encoding overview</h2>
* <p>
* Beider-Morse phonetic encodings is a multi-step process. Firstly, a table of rules is consulted to guess what
* language the word comes from. For example, if it ends in "{@code ault}" then it infers that the word is French.
* Next, the word is translated into a phonetic representation using a language-specific phonetics table. Some runs of
* letters can be pronounced in multiple ways, and a single run of letters may be potentially broken up into phonemes at
* different places, so this stage results in a set of possible language-specific phonetic representations. Lastly, this
* language-specific phonetic representation is processed by a table of rules that re-writes it phonetically taking into
* account systematic pronunciation differences between languages, to move it towards a pan-indo-european phonetic
* representation. Again, sometimes there are multiple ways this could be done and sometimes things that can be
* pronounced in several ways in the source language have only one way to represent them in this average phonetic
* language, so the result is again a set of phonetic spellings.
* </p>
* <p>
* Some names are treated as having multiple parts. This can be due to two things. Firstly, they may be hyphenated. In
* this case, each individual hyphenated word is encoded, and then these are combined end-to-end for the final encoding.
* Secondly, some names have standard prefixes, for example, "{@code Mac/Mc}" in Scottish (English) names. As
* sometimes it is ambiguous whether the prefix is intended or is an accident of the spelling, the word is encoded once
* with the prefix and once without it. The resulting encoding contains one and then the other result.
* </p>
* <h2>Encoding format</h2>
* <p>
* Individual phonetic spellings of an input word are represented in upper- and lower-case roman characters. Where there
* are multiple possible phonetic representations, these are joined with a pipe ({@code |}) character. If multiple
* hyphenated words where found, or if the word may contain a name prefix, each encoded word is placed in ellipses and
* these blocks are then joined with hyphens. For example, "{@code d'ortley}" has a possible prefix. The form
* without prefix encodes to "{@code ortlaj|ortlej}", while the form with prefix encodes to "
* {@code dortlaj|dortlej}". Thus, the full, combined encoding is "{@code (ortlaj|ortlej)-(dortlaj|dortlej)}".
* </p>
* <p>
* The encoded forms are often quite a bit longer than the input strings. This is because a single input may have many
* potential phonetic interpretations. For example, "{@code Renault}" encodes to "
* {@code rYnDlt|rYnalt|rYnult|rinDlt|rinalt|rinult}". The {@code APPROX} rules will tend to produce larger
* encodings as they consider a wider range of possible, approximate phonetic interpretations of the original word.
* Down-stream applications may wish to further process the encoding for indexing or lookup purposes, for example, by
* splitting on pipe ({@code |}) and indexing under each of these alternatives.
* </p>
* <p>
* <b>Note</b>: this version of the Beider-Morse encoding is equivalent with v3.4 of the reference implementation.
* </p>
* @see <a href="https://stevemorse.org/phonetics/bmpm.htm">Beider-Morse Phonetic Matching</a>
* @see <a href="https://stevemorse.org/phoneticinfo.htm">Reference implementation</a>
*
* <p>
* This class is Not ThreadSafe
* </p>
* @since 1.6
*/
public class BeiderMorseEncoder implements StringEncoder {
// Implementation note: This class is a spring-friendly facade to PhoneticEngine. It allows read/write configuration
// of an immutable PhoneticEngine instance that will be delegated to for the actual encoding.
// a cached object
private PhoneticEngine engine = new PhoneticEngine(NameType.GENERIC, RuleType.APPROX, true);
@Override
public Object encode(final Object source) throws EncoderException {
if (!(source instanceof String)) {
throw new EncoderException("BeiderMorseEncoder encode parameter is not of type String");
}
return encode((String) source);
}
@Override
public String encode(final String source) throws EncoderException {
if (source == null) {
return null;
}
return this.engine.encode(source);
}
/**
* Gets the name type currently in operation.
*
* @return the NameType currently being used
*/
public NameType getNameType() {
return this.engine.getNameType();
}
/**
* Gets the rule type currently in operation.
*
* @return the RuleType currently being used
*/
public RuleType getRuleType() {
return this.engine.getRuleType();
}
/**
* Discovers if multiple possible encodings are concatenated.
*
* @return true if multiple encodings are concatenated, false if just the first one is returned
*/
public boolean isConcat() {
return this.engine.isConcat();
}
/**
* Sets how multiple possible phonetic encodings are combined.
*
* @param concat
* true if multiple encodings are to be combined with a '|', false if just the first one is
* to be considered
*/
public void setConcat(final boolean concat) {
this.engine = new PhoneticEngine(this.engine.getNameType(),
this.engine.getRuleType(),
concat,
this.engine.getMaxPhonemes());
}
/**
* Sets the number of maximum of phonemes that shall be considered by the engine.
*
* @param maxPhonemes
* the maximum number of phonemes returned by the engine
* @since 1.7
*/
public void setMaxPhonemes(final int maxPhonemes) {
this.engine = new PhoneticEngine(this.engine.getNameType(),
this.engine.getRuleType(),
this.engine.isConcat(),
maxPhonemes);
}
/**
* Sets the type of name. Use {@link NameType#GENERIC} unless you specifically want phonetic encodings
* optimized for Ashkenazi or Sephardic Jewish family names.
*
* @param nameType
* the NameType in use
*/
public void setNameType(final NameType nameType) {
this.engine = new PhoneticEngine(nameType,
this.engine.getRuleType(),
this.engine.isConcat(),
this.engine.getMaxPhonemes());
}
/**
* Sets the rule type to apply. This will widen or narrow the range of phonetic encodings considered.
*
* @param ruleType
* {@link RuleType#APPROX} or {@link RuleType#EXACT} for approximate or exact phonetic matches
*/
public void setRuleType(final RuleType ruleType) {
this.engine = new PhoneticEngine(this.engine.getNameType(),
ruleType,
this.engine.isConcat(),
this.engine.getMaxPhonemes());
}
}