Legacy Bridge report
Metaphone from Apache Commons Codec 1.3 (2005, real open-source code)
Run 20260926-122205 · src/main/java/org/apache/commons/codec/language/Metaphone.java · 5 Bob calls · 0.233 Bob coins · Bob modernizes; Bob's own characterization tests decide what ships.
117characterization tests written by Bob
passon the untouched legacy code
5/5behaviour mutants caught (hand-written controls: 5/5)
0regressions blocked (0 repaired by Bob and verified)
1. Characterization tests
Bob read the legacy file and wrote MetaphoneCharacterizationTest to pin down what it does today. Bob corrected its own suite in 1 round(s) after it failed on the original. Bob hardened its suite: its first version caught 4/5 mutants; after seeing what slipped through, it caught 5/5.
Each mutant below breaks one known legacy quirk; a good safety net must catch every one.
| Mutant | Legacy quirk it breaks | Result | Caught by |
|---|---|---|---|
M1-duplicate-C | Repeated letters are skipped, except C ("ACCEPT" keeps both Cs' sounds) | caught | MetaphoneCharacterizationTest.duplicateCIsNotSuppressed, MetaphoneCharacterizationTest.acceptCcBeforeE, MetaphoneCharacterizationTest.succeedEncoding2 |
M2-single-char-path | A one-letter input is returned upper-cased without running the algorithm (the general path would index past the end) | caught | MetaphoneCharacterizationTest.singleUppercaseLetterIsReturnedAsIs, MetaphoneCharacterizationTest.singleLowercaseLetterIsUppercased |
M3-initial-X | An initial X is pronounced S ("XAVIER") | caught | MetaphoneCharacterizationTest.xavierEncoding, MetaphoneCharacterizationTest.initialXBecomesS, MetaphoneCharacterizationTest.nonInitialXBecomesKS |
M4-WH-to-W | An initial WH becomes W ("WHITE") | caught | MetaphoneCharacterizationTest.hBeforeVowelIncluded, MetaphoneCharacterizationTest.whetherEncoding |
M5-silent-TCH | The T in TCH is silent ("MATCH") | caught | MetaphoneCharacterizationTest.tchTIsSilentInCatch, MetaphoneCharacterizationTest.tchTIsSilentInFetch, MetaphoneCharacterizationTest.tchTIsSilentInMatch |
Transcripts: 20260926T122205Z-metaphone-generate-tests-replay.md 20260926T122206Z-metaphone-fix-tests-replay.md 20260926T122214Z-metaphone-harden-tests-cli.md
2. Modernization: VERIFIED
Request: Bring this class up to modern Java 21: generics instead of raw collections, java.time instead of Calendar, StringBuilder, no deprecated APIs. Behaviour must stay exactly the same.
117/117 characterization tests pass. Applied to out/metaphone/Metaphone.java.
Diff (legacy → Bob)
--- legacy/Metaphone.java +++ bob/Metaphone.java @@ -1,18 +1,18 @@ /* * Copyright 2001-2004 The Apache Software Foundation. - * + * * Licensed 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.commons.codec.language; @@ -20,365 +20,338 @@ import org.apache.commons.codec.StringEncoder; /** - * Encodes a string into a metaphone value. + * Encodes a string into a metaphone value. * <p> - * Initial Java implementation by <CITE>William B. Brogden. December, 1997</CITE>. + * Initial Java implementation by <CITE>William B. Brogden. December, 1997</CITE>. * Permission given by <CITE>wbrogden</CITE> for code to be used anywhere. * </p> * <p> - * <CITE>Hanging on the Metaphone</CITE> by <CITE>Lawrence Philips</CITE> in <CITE>Computer Language of Dec. 1990, p - * 39.</CITE> + * <CITE>Hanging on the Metaphone</CITE> by <CITE>Lawrence Philips</CITE> in + * <CITE>Computer Language of Dec. 1990, p 39.</CITE> * </p> - * + * * @author Apache Software Foundation * @version $Id: Metaphone.java,v 1.20 2004/06/05 18:32:04 ggregory Exp $ */ public class Metaphone implements StringEncoder { - /** - * Five values in the English language - */ - private String vowels = "AEIOU" ; - - /** - * Variable used in Metaphone algorithm - */ - private String frontv = "EIY" ; - - /** - * Variable used in Metaphone algorithm - */ - private String varson = "CSPTG" ; - - /** - * The max code length for metaphone is 4 - */ - private int maxCodeLen = 4 ; - - /** - * Creates an instance of the Metaphone encoder + /** Five vowels in the English language */ + private static final String VOWELS = "AEIOU"; + + /** Variable used in Metaphone algorithm */ + private static final String FRONTV = "EIY"; + + /** Variable used in Metaphone algorithm */ + private static final String VARSON = "CSPTG"; + + /** The max code length for metaphone is 4 */ + private int maxCodeLen = 4; + + /** + * Creates an instance of the Metaphone encoder. */ public Metaphone() { super(); } /** - * Find the metaphone value of a String. This is similar to the - * soundex algorithm, but better at finding similar sounding words. - * All input is converted to upper case. - * Limitations: Input format is expected to be a single ASCII word - * with only characters in the A - Z range, no punctuation or numbers. + * Find the metaphone value of a String. This is similar to the soundex algorithm, + * but better at finding similar sounding words. All input is converted to upper case. + * Limitations: Input format is expected to be a single ASCII word with only characters + * in the A - Z range, no punctuation or numbers. * * @param txt String to find the metaphone code for * @return A metaphone code corresponding to the String supplied */ public String metaphone(String txt) { - boolean hard = false ; + boolean hard = false; if ((txt == null) || (txt.length() == 0)) { - return "" ; + return ""; } // single character is itself if (txt.length() == 1) { - return txt.toUpperCase() ; - } - - char[] inwd = txt.toUpperCase().toCharArray() ; - - StringBuffer local = new StringBuffer(40); // manipulate - StringBuffer code = new StringBuffer(10) ; // output + return txt.toUpperCase(); + } + + char[] inwd = txt.toUpperCase().toCharArray(); + + StringBuilder local = new StringBuilder(40); // manipulate + StringBuilder code = new StringBuilder(10); // output + // handle initial 2 characters exceptions - switch(inwd[0]) { - case 'K' : - case 'G' : - case 'P' : /* looking for KN, etc*/ - if (inwd[1] == 'N') { - local.append(inwd, 1, inwd.length - 1); - } else { + switch (inwd[0]) { + case 'K': + case 'G': + case 'P': /* looking for KN, etc */ + if (inwd[1] == 'N') { + local.append(inwd, 1, inwd.length - 1); + } else { + local.append(inwd); + } + break; + case 'A': /* looking for AE */ + if (inwd[1] == 'E') { + local.append(inwd, 1, inwd.length - 1); + } else { + local.append(inwd); + } + break; + case 'W': /* looking for WR or WH */ + if (inwd[1] == 'R') { // WR -> R + local.append(inwd, 1, inwd.length - 1); + break; + } + if (inwd[1] == 'H') { + local.append(inwd, 1, inwd.length - 1); + local.setCharAt(0, 'W'); // WH -> W + } else { + local.append(inwd); + } + break; + case 'X': /* initial X becomes S */ + inwd[0] = 'S'; local.append(inwd); + break; + default: + local.append(inwd); + } // now local has working string with initials fixed + + int wdsz = local.length(); + int n = 0; + + while ((code.length() < this.getMaxCodeLen()) && (n < wdsz)) { + char symb = local.charAt(n); + // remove duplicate letters except C + if ((symb != 'C') && isPreviousChar(local, n, symb)) { + n++; + } else { // not dup + switch (symb) { + case 'A': case 'E': case 'I': case 'O': case 'U': + if (n == 0) { + code.append(symb); + } + break; // only use vowel if leading char + case 'B': + // B is silent if word ends in MB + if (isPreviousChar(local, n, 'M') && isLastChar(wdsz, n)) { + break; + } + code.append(symb); + break; + case 'C': // lots of C special cases + /* discard if SCI, SCE or SCY */ + if (isPreviousChar(local, n, 'S') && + !isLastChar(wdsz, n) && + (FRONTV.indexOf(local.charAt(n + 1)) >= 0)) { + break; + } + if (regionMatch(local, n, "CIA")) { // "CIA" -> X + code.append('X'); + break; + } + if (!isLastChar(wdsz, n) && + (FRONTV.indexOf(local.charAt(n + 1)) >= 0)) { + code.append('S'); + break; // CI,CE,CY -> S + } + if (isPreviousChar(local, n, 'S') && isNextChar(local, n, 'H')) { // SCH->sk + code.append('K'); + break; + } + if (isNextChar(local, n, 'H')) { // detect CH + if ((n == 0) && (wdsz >= 3) && isVowel(local, 2)) { + code.append('K'); // CH consonant -> K consonant + } else { + code.append('X'); // CHvowel -> X + } + } else { + code.append('K'); + } + break; + case 'D': + if (!isLastChar(wdsz, n + 1) && + isNextChar(local, n, 'G') && + (FRONTV.indexOf(local.charAt(n + 2)) >= 0)) { // DGE DGI DGY -> J + code.append('J'); + n += 2; + } else { + code.append('T'); + } + break; + case 'G': // GH silent at end or before consonant + if (isLastChar(wdsz, n + 1) && isNextChar(local, n, 'H')) { + break; + } + if (!isLastChar(wdsz, n + 1) && + isNextChar(local, n, 'H') && + !isVowel(local, n + 2)) { + break; + } + if ((n > 0) && + (regionMatch(local, n, "GN") || regionMatch(local, n, "GNED"))) { + break; // silent G + } + hard = isPreviousChar(local, n, 'G'); + if (!isLastChar(wdsz, n) && + (FRONTV.indexOf(local.charAt(n + 1)) >= 0) && + !hard) { + code.append('J'); + } else { + code.append('K'); + } + break; + case 'H': + if (isLastChar(wdsz, n)) { + break; // terminal H + } + if ((n > 0) && (VARSON.indexOf(local.charAt(n - 1)) >= 0)) { + break; + } + if (isVowel(local, n + 1)) { + code.append('H'); // Hvowel + } + break; + case 'F': + case 'J': + case 'L': + case 'M': + case 'N': + case 'R': + code.append(symb); + break; + case 'K': + if (n > 0) { // not initial + if (!isPreviousChar(local, n, 'C')) { + code.append(symb); + } + } else { + code.append(symb); // initial K + } + break; + case 'P': + if (isNextChar(local, n, 'H')) { + code.append('F'); // PH -> F + } else { + code.append(symb); + } + break; + case 'Q': + code.append('K'); + break; + case 'S': + if (regionMatch(local, n, "SH") || + regionMatch(local, n, "SIO") || + regionMatch(local, n, "SIA")) { + code.append('X'); + } else { + code.append('S'); + } + break; + case 'T': + if (regionMatch(local, n, "TIA") || regionMatch(local, n, "TIO")) { + code.append('X'); + break; + } + if (regionMatch(local, n, "TCH")) { + break; // silent if in "TCH" + } + // substitute numeral 0 for TH (resembles theta after all) + if (regionMatch(local, n, "TH")) { + code.append('0'); + } else { + code.append('T'); + } + break; + case 'V': + code.append('F'); + break; + case 'W': case 'Y': // silent if not followed by vowel + if (!isLastChar(wdsz, n) && isVowel(local, n + 1)) { + code.append(symb); + } + break; + case 'X': + code.append('K'); + code.append('S'); + break; + case 'Z': + code.append('S'); + break; + } // end switch + n++; + } // end else from symb != 'C' + if (code.length() > this.getMaxCodeLen()) { + code.setLength(this.getMaxCodeLen()); } - break; - case 'A': /* looking for AE */ - if (inwd[1] == 'E') { - local.append(inwd, 1, inwd.length - 1); - } else { - local.append(inwd); - } - break; - case 'W' : /* looking for WR or WH */ - if (inwd[1] == 'R') { // WR -> R - local.append(inwd, 1, inwd.length - 1); - break ; - } - if (inwd[1] == 'H') { - local.append(inwd, 1, inwd.length - 1); - local.setCharAt(0, 'W'); // WH -> W - } else { - local.append(inwd); - } - break; - case 'X' : /* initial X becomes S */ - inwd[0] = 'S'; - local.append(inwd); - break ; - default : - local.append(inwd); - } // now local has working string with initials fixed - - int wdsz = local.length(); - int n = 0 ; - - while ((code.length() < this.getMaxCodeLen()) && - (n < wdsz) ) { // max code size of 4 works well - char symb = local.charAt(n) ; - // remove duplicate letters except C - if ((symb != 'C') && (isPreviousChar( local, n, symb )) ) { - n++ ; - } else { // not dup - switch(symb) { - case 'A' : case 'E' : case 'I' : case 'O' : case 'U' : - if (n == 0) { - code.append(symb); - } - break ; // only use vowel if leading char - case 'B' : - if ( isPreviousChar(local, n, 'M') && - isLastChar(wdsz, n) ) { // B is silent if word ends in MB - break; - } - code.append(symb); - break; - case 'C' : // lots of C special cases - /* discard if SCI, SCE or SCY */ - if ( isPreviousChar(local, n, 'S') && - !isLastChar(wdsz, n) && - (this.frontv.indexOf(local.charAt(n + 1)) >= 0) ) { - break; - } - if (regionMatch(local, n, "CIA")) { // "CIA" -> X - code.append('X'); - break; - } - if (!isLastChar(wdsz, n) && - (this.frontv.indexOf(local.charAt(n + 1)) >= 0)) { - code.append('S'); - break; // CI,CE,CY -> S - } - if (isPreviousChar(local, n, 'S') && - isNextChar(local, n, 'H') ) { // SCH->sk - code.append('K') ; - break ; - } - if (isNextChar(local, n, 'H')) { // detect CH - if ((n == 0) && - (wdsz >= 3) && - isVowel(local,2) ) { // CH consonant -> K consonant - code.append('K'); - } else { - code.append('X'); // CHvowel -> X - } - } else { - code.append('K'); - } - break ; - case 'D' : - if (!isLastChar(wdsz, n + 1) && - isNextChar(local, n, 'G') && - (this.frontv.indexOf(local.charAt(n + 2)) >= 0)) { // DGE DGI DGY -> J - code.append('J'); n += 2 ; - } else { - code.append('T'); - } - break ; - case 'G' : // GH silent at end or before consonant - if (isLastChar(wdsz, n + 1) && - isNextChar(local, n, 'H')) { - break; - } - if (!isLastChar(wdsz, n + 1) && - isNextChar(local,n,'H') && - !isVowel(local,n+2)) { - break; - } - if ((n > 0) && - ( regionMatch(local, n, "GN") || - regionMatch(local, n, "GNED") ) ) { - break; // silent G - } - if (isPreviousChar(local, n, 'G')) { - hard = true ; - } else { - hard = false ; - } - if (!isLastChar(wdsz, n) && - (this.frontv.indexOf(local.charAt(n + 1)) >= 0) && - (!hard)) { - code.append('J'); - } else { - code.append('K'); - } - break ; - case 'H': - if (isLastChar(wdsz, n)) { - break ; // terminal H - } - if ((n > 0) && - (this.varson.indexOf(local.charAt(n - 1)) >= 0)) { - break; - } - if (isVowel(local,n+1)) { - code.append('H'); // Hvowel - } - break; - case 'F': - case 'J' : - case 'L' : - case 'M': - case 'N' : - case 'R' : - code.append(symb); - break; - case 'K' : - if (n > 0) { // not initial - if (!isPreviousChar(local, n, 'C')) { - code.append(symb); - } - } else { - code.append(symb); // initial K - } - break ; - case 'P' : - if (isNextChar(local,n,'H')) { - // PH -> F - code.append('F'); - } else { - code.append(symb); - } - break ; - case 'Q' : - code.append('K'); - break; - case 'S' : - if (regionMatch(local,n,"SH") || - regionMatch(local,n,"SIO") || - regionMatch(local,n,"SIA")) { - code.append('X'); - } else { - code.append('S'); - } - break; - case 'T' : - if (regionMatch(local,n,"TIA") || - regionMatch(local,n,"TIO")) { - code.append('X'); - break; - } - if (regionMatch(local,n,"TCH")) { - // Silent if in "TCH" - break; - } - // substitute numeral 0 for TH (resembles theta after all) - if (regionMatch(local,n,"TH")) { - code.append('0'); - } else { - code.append('T'); - } - break ; - case 'V' : - code.append('F'); break ; - case 'W' : case 'Y' : // silent if not followed by vowel - if (!isLastChar(wdsz,n) && - isVowel(local,n+1)) { - code.append(symb); - } - break ; - case 'X' : - code.append('K'); code.append('S'); - break ; - case 'Z' : - code.append('S'); break ; - } // end switch - n++ ; - } // end else from symb != 'C' - if (code.length() > this.getMaxCodeLen()) { - code.setLength(this.getMaxCodeLen()); - } } return code.toString(); } - private boolean isVowel(StringBuffer string, int index) { - return (this.vowels.indexOf(string.charAt(index)) >= 0); - } - - private boolean isPreviousChar(StringBuffer string, int index, char c) { - boolean matches = false; - if( index > 0 && - index < string.length() ) { - matches = string.charAt(index - 1) == c; - } - return matches; - } - - private boolean isNextChar(StringBuffer string, int index, char c) { - boolean matches = false; - if( index >= 0 && - index < string.length() - 1 ) { - matches = string.charAt(index + 1) == c; - } - return matches; - } - - private boolean regionMatch(StringBuffer string, int index, String test) { - boolean matches = false; - if( index >= 0 && - (index + test.length() - 1) < string.length() ) { - String substring = string.substring( index, index + test.length()); - matches = substring.equals( test ); - } - return matches; - } - - private boolean isLastChar(int wdsz, int n) { - return n + 1 == wdsz; - } - - - /** - * Encodes an Object using the metaphone algorithm. This method - * is provided in order to satisfy the requirements of the - * Encoder interface, and will throw an EncoderException if the - * supplied object is not of type java.lang.String. + private boolean isVowel(StringBuilder string, int index) { + return (VOWELS.indexOf(string.charAt(index)) >= 0); + } + + private boolean isPreviousChar(StringBuilder string, int index, char c) { + if (index > 0 && index < string.length()) { + return string.charAt(index - 1) == c; + } + return false; + } + + private boolean isNextChar(StringBuilder string, int index, char c) { + if (index >= 0 && index < string.length() - 1) { + return string.charAt(index + 1) == c; + } + return false; + } + + private boolean regionMatch(StringBuilder string, int index, String test) { + if (index >= 0 && (index + test.length() - 1) < string.length()) { + return string.substring(index, index + test.length()).equals(test); + } + return false; + } + + private boolean isLastChar(int wdsz, int n) { + return n + 1 == wdsz; + } + + /** + * Encodes an Object using the metaphone algorithm. This method is provided in order to + * satisfy the requirements of the Encoder interface, and will throw an EncoderException + * if the supplied object is not of type java.lang.String. * * @param pObject Object to encode - * @return An object (or type java.lang.String) containing the - * metaphone code which corresponds to the String supplied. - * @throws EncoderException if the parameter supplied is not - * of type java.lang.String - */ + * @return An object (or type java.lang.String) containing the metaphone code which + * corresponds to the String supplied. + * @throws EncoderException if the parameter supplied is not of type java.lang.String + */ + @Override public Object encode(Object pObject) throws EncoderException { - if (!(pObject instanceof java.lang.String)) { - throw new EncoderException("Parameter supplied to Metaphone encode is not of type java.lang.String"); + if (!(pObject instanceof String)) { + throw new EncoderException( + "Parameter supplied to Metaphone encode is not of type java.lang.String"); } return metaphone((String) pObject); } /** - * Encodes a String using the Metaphone algorithm. + * Encodes a String using the Metaphone algorithm. * * @param pString String object to encode * @return The metaphone code corresponding to the String supplied */ + @Override public String encode(String pString) { - return metaphone(pString); - } - - /** - * Tests is the metaphones of two strings are identical. + return metaphone(pString); + } + + /** + * Tests if the metaphones of two strings are identical. * * @param str1 First of two strings to compare * @param str2 Second of two strings to compare - * @return true if the metaphones of these strings are identical, - * false otherwise. + * @return true if the metaphones of these strings are identical, false otherwise. */ public boolean isMetaphoneEqual(String str1, String str2) { return metaphone(str1).equals(metaphone(str2)); @@ -386,14 +359,15 @@ /** * Returns the maxCodeLen. + * * @return int */ public int getMaxCodeLen() { return this.maxCodeLen; } /** * Sets the maxCodeLen. + * * @param maxCodeLen The maxCodeLen to set */ public void setMaxCodeLen(int maxCodeLen) { this.maxCodeLen = maxCodeLen; } - }
Transcript: 20260926T122518Z-metaphone-benign-cli.md
3. Modernization: VERIFIED
Request: Ticket SRCH-431 (tech debt): Metaphone is Java 1.4-era code - StringBuffer, char arrays, a 170-line switch and duplicated special-case branches. Refactor it for readability with modern Java 21: StringBuilder, switch expressions, small helper methods, and simplify the special-case handling. Keep the public API.
117/117 characterization tests pass. Applied to out/metaphone/Metaphone.java.
Diff (legacy → Bob)
--- legacy/Metaphone.java +++ bob/Metaphone.java @@ -1,18 +1,18 @@ /* * Copyright 2001-2004 The Apache Software Foundation. - * + * * Licensed 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.commons.codec.language; @@ -20,365 +20,299 @@ import org.apache.commons.codec.StringEncoder; /** - * Encodes a string into a metaphone value. + * Encodes a string into a metaphone value. * <p> - * Initial Java implementation by <CITE>William B. Brogden. December, 1997</CITE>. + * Initial Java implementation by <CITE>William B. Brogden. December, 1997</CITE>. * Permission given by <CITE>wbrogden</CITE> for code to be used anywhere. * </p> * <p> - * <CITE>Hanging on the Metaphone</CITE> by <CITE>Lawrence Philips</CITE> in <CITE>Computer Language of Dec. 1990, p - * 39.</CITE> + * <CITE>Hanging on the Metaphone</CITE> by <CITE>Lawrence Philips</CITE> in + * <CITE>Computer Language of Dec. 1990, p 39.</CITE> * </p> - * + * * @author Apache Software Foundation * @version $Id: Metaphone.java,v 1.20 2004/06/05 18:32:04 ggregory Exp $ */ public class Metaphone implements StringEncoder { - /** - * Five values in the English language - */ - private String vowels = "AEIOU" ; - - /** - * Variable used in Metaphone algorithm - */ - private String frontv = "EIY" ; - - /** - * Variable used in Metaphone algorithm - */ - private String varson = "CSPTG" ; - - /** - * The max code length for metaphone is 4 - */ - private int maxCodeLen = 4 ; - - /** - * Creates an instance of the Metaphone encoder - */ + private static final String VOWELS = "AEIOU"; + private static final String FRONTV = "EIY"; + private static final String VARSON = "CSPTG"; + + private int maxCodeLen = 4; + public Metaphone() { super(); } /** - * Find the metaphone value of a String. This is similar to the - * soundex algorithm, but better at finding similar sounding words. - * All input is converted to upper case. - * Limitations: Input format is expected to be a single ASCII word - * with only characters in the A - Z range, no punctuation or numbers. + * Find the metaphone value of a String. This is similar to the soundex algorithm, + * but better at finding similar sounding words. All input is converted to upper case. + * Limitations: Input format is expected to be a single ASCII word with only characters + * in the A - Z range, no punctuation or numbers. * * @param txt String to find the metaphone code for * @return A metaphone code corresponding to the String supplied */ public String metaphone(String txt) { - boolean hard = false ; - if ((txt == null) || (txt.length() == 0)) { - return "" ; - } - // single character is itself + if (txt == null || txt.isEmpty()) { + return ""; + } if (txt.length() == 1) { - return txt.toUpperCase() ; - } - - char[] inwd = txt.toUpperCase().toCharArray() ; - - StringBuffer local = new StringBuffer(40); // manipulate - StringBuffer code = new StringBuffer(10) ; // output - // handle initial 2 characters exceptions - switch(inwd[0]) { - case 'K' : - case 'G' : - case 'P' : /* looking for KN, etc*/ - if (inwd[1] == 'N') { - local.append(inwd, 1, inwd.length - 1); + return txt.toUpperCase(); + } + + String upper = txt.toUpperCase(); + StringBuilder local = normalizeInitial(upper); + StringBuilder code = new StringBuilder(10); + + int wdsz = local.length(); + int n = 0; + + while (code.length() < maxCodeLen && n < wdsz) { + char symb = local.charAt(n); + // skip duplicate letters, except C + if (symb != 'C' && isPreviousChar(local, n, symb)) { + n++; + continue; + } + n = processChar(local, code, wdsz, n, symb); + if (code.length() > maxCodeLen) { + code.setLength(maxCodeLen); + } + } + return code.toString(); + } + + // ------------------------------------------------------------------------- + // Normalise the first character(s) of the uppercased word + // ------------------------------------------------------------------------- + + private StringBuilder normalizeInitial(String upper) { + char first = upper.charAt(0); + char second = upper.charAt(1); + return switch (first) { + case 'K', 'G', 'P' -> // KN / GN / PN → drop leading consonant + second == 'N' ? new StringBuilder(upper.substring(1)) + : new StringBuilder(upper); + case 'A' -> // AE → drop the A + second == 'E' ? new StringBuilder(upper.substring(1)) + : new StringBuilder(upper); + case 'W' -> normalizeW(upper, second); + case 'X' -> { // initial X → S + StringBuilder sb = new StringBuilder(upper); + sb.setCharAt(0, 'S'); + yield sb; + } + default -> new StringBuilder(upper); + }; + } + + private StringBuilder normalizeW(String upper, char second) { + return switch (second) { + case 'R' -> new StringBuilder(upper.substring(1)); // WR → R + case 'H' -> { // WH → W + StringBuilder sb = new StringBuilder(upper.substring(1)); + sb.setCharAt(0, 'W'); + yield sb; + } + default -> new StringBuilder(upper); + }; + } + + // ------------------------------------------------------------------------- + // Per-character processing — returns the next value of n + // ------------------------------------------------------------------------- + + private int processChar( + StringBuilder local, StringBuilder code, int wdsz, int n, char symb) { + switch (symb) { + case 'A', 'E', 'I', 'O', 'U' -> { + if (n == 0) code.append(symb); + } + case 'B' -> { + if (!(isPreviousChar(local, n, 'M') && isLastChar(wdsz, n))) { + code.append(symb); + } + } + case 'C' -> { return processC(local, code, wdsz, n); } + case 'D' -> { return processD(local, code, wdsz, n); } + case 'G' -> processG(local, code, wdsz, n); + case 'H' -> processH(local, code, wdsz, n); + case 'F', 'J', 'L', 'M', 'N', 'R' -> code.append(symb); + case 'K' -> { + if (n == 0 || !isPreviousChar(local, n, 'C')) { + code.append(symb); + } + } + case 'P' -> code.append(isNextChar(local, n, 'H') ? 'F' : symb); + case 'Q' -> code.append('K'); + case 'S' -> processS(local, code, n); + case 'T' -> processT(local, code, n); + case 'V' -> code.append('F'); + case 'W', 'Y' -> { + if (!isLastChar(wdsz, n) && isVowel(local, n + 1)) { + code.append(symb); + } + } + case 'X' -> { code.append('K'); code.append('S'); } + case 'Z' -> code.append('S'); + } + return n + 1; + } + + private int processC(StringBuilder local, StringBuilder code, int wdsz, int n) { + // SCI / SCE / SCY → silent C + if (isPreviousChar(local, n, 'S') + && !isLastChar(wdsz, n) + && isFrontVowel(local, n + 1)) { + return n + 1; + } + if (regionMatch(local, n, "CIA")) { + code.append('X'); + return n + 1; + } + if (!isLastChar(wdsz, n) && isFrontVowel(local, n + 1)) { + code.append('S'); // CI / CE / CY → S + return n + 1; + } + if (isPreviousChar(local, n, 'S') && isNextChar(local, n, 'H')) { + code.append('K'); // SCH → SK + return n + 1; + } + if (isNextChar(local, n, 'H')) { + // CH consonant → K, CH vowel → X + if (n == 0 && wdsz >= 3 && isVowel(local, 2)) { + code.append('K'); } else { - local.append(inwd); - } - break; - case 'A': /* looking for AE */ - if (inwd[1] == 'E') { - local.append(inwd, 1, inwd.length - 1); - } else { - local.append(inwd); - } - break; - case 'W' : /* looking for WR or WH */ - if (inwd[1] == 'R') { // WR -> R - local.append(inwd, 1, inwd.length - 1); - break ; - } - if (inwd[1] == 'H') { - local.append(inwd, 1, inwd.length - 1); - local.setCharAt(0, 'W'); // WH -> W - } else { - local.append(inwd); - } - break; - case 'X' : /* initial X becomes S */ - inwd[0] = 'S'; - local.append(inwd); - break ; - default : - local.append(inwd); - } // now local has working string with initials fixed - - int wdsz = local.length(); - int n = 0 ; - - while ((code.length() < this.getMaxCodeLen()) && - (n < wdsz) ) { // max code size of 4 works well - char symb = local.charAt(n) ; - // remove duplicate letters except C - if ((symb != 'C') && (isPreviousChar( local, n, symb )) ) { - n++ ; - } else { // not dup - switch(symb) { - case 'A' : case 'E' : case 'I' : case 'O' : case 'U' : - if (n == 0) { - code.append(symb); - } - break ; // only use vowel if leading char - case 'B' : - if ( isPreviousChar(local, n, 'M') && - isLastChar(wdsz, n) ) { // B is silent if word ends in MB - break; - } - code.append(symb); - break; - case 'C' : // lots of C special cases - /* discard if SCI, SCE or SCY */ - if ( isPreviousChar(local, n, 'S') && - !isLastChar(wdsz, n) && - (this.frontv.indexOf(local.charAt(n + 1)) >= 0) ) { - break; - } - if (regionMatch(local, n, "CIA")) { // "CIA" -> X - code.append('X'); - break; - } - if (!isLastChar(wdsz, n) && - (this.frontv.indexOf(local.charAt(n + 1)) >= 0)) { - code.append('S'); - break; // CI,CE,CY -> S - } - if (isPreviousChar(local, n, 'S') && - isNextChar(local, n, 'H') ) { // SCH->sk - code.append('K') ; - break ; - } - if (isNextChar(local, n, 'H')) { // detect CH - if ((n == 0) && - (wdsz >= 3) && - isVowel(local,2) ) { // CH consonant -> K consonant - code.append('K'); - } else { - code.append('X'); // CHvowel -> X - } - } else { - code.append('K'); - } - break ; - case 'D' : - if (!isLastChar(wdsz, n + 1) && - isNextChar(local, n, 'G') && - (this.frontv.indexOf(local.charAt(n + 2)) >= 0)) { // DGE DGI DGY -> J - code.append('J'); n += 2 ; - } else { - code.append('T'); - } - break ; - case 'G' : // GH silent at end or before consonant - if (isLastChar(wdsz, n + 1) && - isNextChar(local, n, 'H')) { - break; - } - if (!isLastChar(wdsz, n + 1) && - isNextChar(local,n,'H') && - !isVowel(local,n+2)) { - break; - } - if ((n > 0) && - ( regionMatch(local, n, "GN") || - regionMatch(local, n, "GNED") ) ) { - break; // silent G - } - if (isPreviousChar(local, n, 'G')) { - hard = true ; - } else { - hard = false ; - } - if (!isLastChar(wdsz, n) && - (this.frontv.indexOf(local.charAt(n + 1)) >= 0) && - (!hard)) { - code.append('J'); - } else { - code.append('K'); - } - break ; - case 'H': - if (isLastChar(wdsz, n)) { - break ; // terminal H - } - if ((n > 0) && - (this.varson.indexOf(local.charAt(n - 1)) >= 0)) { - break; - } - if (isVowel(local,n+1)) { - code.append('H'); // Hvowel - } - break; - case 'F': - case 'J' : - case 'L' : - case 'M': - case 'N' : - case 'R' : - code.append(symb); - break; - case 'K' : - if (n > 0) { // not initial - if (!isPreviousChar(local, n, 'C')) { - code.append(symb); - } - } else { - code.append(symb); // initial K - } - break ; - case 'P' : - if (isNextChar(local,n,'H')) { - // PH -> F - code.append('F'); - } else { - code.append(symb); - } - break ; - case 'Q' : - code.append('K'); - break; - case 'S' : - if (regionMatch(local,n,"SH") || - regionMatch(local,n,"SIO") || - regionMatch(local,n,"SIA")) { - code.append('X'); - } else { - code.append('S'); - } - break; - case 'T' : - if (regionMatch(local,n,"TIA") || - regionMatch(local,n,"TIO")) { - code.append('X'); - break; - } - if (regionMatch(local,n,"TCH")) { - // Silent if in "TCH" - break; - } - // substitute numeral 0 for TH (resembles theta after all) - if (regionMatch(local,n,"TH")) { - code.append('0'); - } else { - code.append('T'); - } - break ; - case 'V' : - code.append('F'); break ; - case 'W' : case 'Y' : // silent if not followed by vowel - if (!isLastChar(wdsz,n) && - isVowel(local,n+1)) { - code.append(symb); - } - break ; - case 'X' : - code.append('K'); code.append('S'); - break ; - case 'Z' : - code.append('S'); break ; - } // end switch - n++ ; - } // end else from symb != 'C' - if (code.length() > this.getMaxCodeLen()) { - code.setLength(this.getMaxCodeLen()); - } - } - return code.toString(); - } - - private boolean isVowel(StringBuffer string, int index) { - return (this.vowels.indexOf(string.charAt(index)) >= 0); - } - - private boolean isPreviousChar(StringBuffer string, int index, char c) { - boolean matches = false; - if( index > 0 && - index < string.length() ) { - matches = string.charAt(index - 1) == c; - } - return matches; - } - - private boolean isNextChar(StringBuffer string, int index, char c) { - boolean matches = false; - if( index >= 0 && - index < string.length() - 1 ) { - matches = string.charAt(index + 1) == c; - } - return matches; - } - - private boolean regionMatch(StringBuffer string, int index, String test) { - boolean matches = false; - if( index >= 0 && - (index + test.length() - 1) < string.length() ) { - String substring = string.substring( index, index + test.length()); - matches = substring.equals( test ); - } - return matches; - } - - private boolean isLastChar(int wdsz, int n) { - return n + 1 == wdsz; - } - - - /** - * Encodes an Object using the metaphone algorithm. This method - * is provided in order to satisfy the requirements of the - * Encoder interface, and will throw an EncoderException if the - * supplied object is not of type java.lang.String. + code.append('X'); + } + } else { + code.append('K'); + } + return n + 1; + } + + private int processD(StringBuilder local, StringBuilder code, int wdsz, int n) { + // DGE / DGI / DGY → J + if (!isLastChar(wdsz, n + 1) + && isNextChar(local, n, 'G') + && isFrontVowel(local, n + 2)) { + code.append('J'); + return n + 3; + } + code.append('T'); + return n + 1; + } + + private void processG(StringBuilder local, StringBuilder code, int wdsz, int n) { + // GH silent at end or before a consonant + if (isNextChar(local, n, 'H')) { + if (isLastChar(wdsz, n + 1)) return; + if (!isVowel(local, n + 2)) return; + } + // GN / GNED → silent G + if (n > 0 && (regionMatch(local, n, "GN") || regionMatch(local, n, "GNED"))) { + return; + } + boolean hard = isPreviousChar(local, n, 'G'); + if (!isLastChar(wdsz, n) && isFrontVowel(local, n + 1) && !hard) { + code.append('J'); + } else { + code.append('K'); + } + } + + private void processH(StringBuilder local, StringBuilder code, int wdsz, int n) { + if (isLastChar(wdsz, n)) return; + if (n > 0 && VARSON.indexOf(local.charAt(n - 1)) >= 0) return; + if (isVowel(local, n + 1)) code.append('H'); + } + + private void processS(StringBuilder local, StringBuilder code, int n) { + if (regionMatch(local, n, "SH") + || regionMatch(local, n, "SIO") + || regionMatch(local, n, "SIA")) { + code.append('X'); + } else { + code.append('S'); + } + } + + private void processT(StringBuilder local, StringBuilder code, int n) { + if (regionMatch(local, n, "TIA") || regionMatch(local, n, "TIO")) { + code.append('X'); + return; + } + if (regionMatch(local, n, "TCH")) return; // silent in TCH + code.append(regionMatch(local, n, "TH") ? '0' : 'T'); + } + + // ------------------------------------------------------------------------- + // Helper predicates + // ------------------------------------------------------------------------- + + private boolean isVowel(StringBuilder s, int index) { + return index >= 0 && index < s.length() && VOWELS.indexOf(s.charAt(index)) >= 0; + } + + private boolean isFrontVowel(StringBuilder s, int index) { + return index >= 0 && index < s.length() && FRONTV.indexOf(s.charAt(index)) >= 0; + } + + private boolean isPreviousChar(StringBuilder s, int index, char c) { + return index > 0 && index < s.length() && s.charAt(index - 1) == c; + } + + private boolean isNextChar(StringBuilder s, int index, char c) { + return index >= 0 && index < s.length() - 1 && s.charAt(index + 1) == c; + } + + private boolean regionMatch(StringBuilder s, int index, String test) { + int end = index + test.length(); + return index >= 0 && end <= s.length() && s.substring(index, end).equals(test); + } + + private boolean isLastChar(int wdsz, int n) { + return n + 1 == wdsz; + } + + // ------------------------------------------------------------------------- + // StringEncoder / public API + // ------------------------------------------------------------------------- + + /** + * Encodes an Object using the metaphone algorithm. Throws EncoderException + * if the supplied object is not of type java.lang.String. * * @param pObject Object to encode - * @return An object (or type java.lang.String) containing the - * metaphone code which corresponds to the String supplied. - * @throws EncoderException if the parameter supplied is not - * of type java.lang.String + * @return A String containing the metaphone code for the supplied String. + * @throws EncoderException if the parameter is not of type java.lang.String */ public Object encode(Object pObject) throws EncoderException { - if (!(pObject instanceof java.lang.String)) { - throw new EncoderException("Parameter supplied to Metaphone encode is not of type java.lang.String"); - } - return metaphone((String) pObject); - } - - /** - * Encodes a String using the Metaphone algorithm. + if (!(pObject instanceof String s)) { + throw new EncoderException( + "Parameter supplied to Metaphone encode is not of type java.lang.String"); + } + return metaphone(s); + } + + /** + * Encodes a String using the Metaphone algorithm. * * @param pString String object to encode * @return The metaphone code corresponding to the String supplied */ public String encode(String pString) { - return metaphone(pString); - } - - /** - * Tests is the metaphones of two strings are identical. + return metaphone(pString); + } + + /** + * Tests if the metaphones of two strings are identical. * * @param str1 First of two strings to compare * @param str2 Second of two strings to compare - * @return true if the metaphones of these strings are identical, - * false otherwise. + * @return true if the metaphones of these strings are identical, false otherwise. */ public boolean isMetaphoneEqual(String str1, String str2) { return metaphone(str1).equals(metaphone(str2)); @@ -395,5 +329,4 @@ * @param maxCodeLen The maxCodeLen to set */ public void setMaxCodeLen(int maxCodeLen) { this.maxCodeLen = maxCodeLen; } - }
Transcript: 20260926T122601Z-metaphone-srch-431-cli.md