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[CODEC-249] Fix Incorrect transform of CH digraph according Metaphone basic rules #423

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Merged
garydgregory merged 3 commits into from
Feb 12, 2026
+25 −12
Merged

[CODEC-249] Fix Incorrect transform of CH digraph according Metaphone basic rules #423

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82af962
[CODEC-249] Fix Incorrect transform of CH digraph according Metaphone…
Shalujha0907 Feb 11, 2026
a546baa
[CODEC-249] Add. test for Metaphone CH character translation with max…
Shalujha0907 Feb 12, 2026
d001404
Remove blank lines.
garydgregory Feb 12, 2026
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16 changes: 6 additions & 10 deletions src/main/java/org/apache/commons/codec/language/Metaphone.java
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Original file line number Diff line number Diff line change
Expand Up @@ -246,23 +246,19 @@ public String metaphone(final String txt) {
if (isPreviousChar(local, n, 'S') && !isLastChar(wdsz, n) && FRONTV.indexOf(local.charAt(n + 1)) >= 0) {
break;
}
if (regionMatch(local, n, "CIA")) { // "CIA" -> X
if (isPreviousChar(local, n, 'S') && isNextChar(local, n, 'H')) { // SCH->sk
code.append('K');
break;
}
if (regionMatch(local, n, "CIA") || isNextChar(local, n, 'H')) { // "CIA" -> X or CH -> 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') || n == 0 && wdsz >= 3 && isVowel(local, 2)) { // CH consonant -> K consonant
code.append('K');
} else {
code.append('X'); // CHvowel -> X
}
code.append('K'); // default C -> K
break;
case 'D':
if (!isLastChar(wdsz, n + 1) && isNextChar(local, n, 'G') && FRONTV.indexOf(local.charAt(n + 2)) >= 0) { // DGE DGI DGY -> J
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21 changes: 19 additions & 2 deletions src/test/java/org/apache/commons/codec/language/MetaphoneTest.java
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Expand Up @@ -272,11 +272,28 @@ void testTIOAndTIAToX() {

@Test
void testTranslateOfSCHAndCH() {
assertEquals("SNS", getStringEncoder().metaphone("SCIENCE"));
assertEquals("SN", getStringEncoder().metaphone("SCENE"));
assertEquals("S", getStringEncoder().metaphone("SCY"));
assertEquals("SKTL", getStringEncoder().metaphone("SCHEDULE"));
assertEquals("SKMT", getStringEncoder().metaphone("SCHEMATIC"));

assertEquals("KRKT", getStringEncoder().metaphone("CHARACTER"));
assertEquals("TSKR", getStringEncoder().metaphone("DISCHARGE"));
assertEquals("EX", getStringEncoder().metaphone("ECHO"));
assertEquals("TX", getStringEncoder().metaphone("TEACH"));
assertEquals("XR", getStringEncoder().metaphone("CHERI"));
assertEquals("XP", getStringEncoder().metaphone("CHIP"));
assertEquals("XRST", getStringEncoder().metaphone("CHRIST"));
assertEquals("X", getStringEncoder().metaphone("CIAO"));
assertEquals("ST", getStringEncoder().metaphone("CITY"));
assertEquals("KT", getStringEncoder().metaphone("CAT"));

}

@Test
void testTranslateOfCHCharacterWithMaxCodeLenFive() {
final Metaphone metaphone = new Metaphone();
metaphone.setMaxCodeLen(5);
assertEquals("XRKTR", metaphone.metaphone("CHARACTER"));
}

@Test
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