languagetool-org/languagetool · error · IllegalArgumentException

minOccurrence must <= maxOccurrence: minOccurrence ${minOccu

Error message

minOccurrence must <= maxOccurrence: minOccurrence ${minOccurrence}, maxOccurrence ${maxOccurrence}

What it means

Builder consistency check fired when PatternTokenBuilder.build() assembles the PatternToken: the previously set minOccurrence exceeds maxOccurrence, which is impossible for a range quantifier. It means the chain of builder calls (e.g. minOccurrence(n) followed by maxOccurrence(m) with m < n) requested an empty occurrence range.

Source

Thrown at languagetool-core/src/main/java/org/languagetool/rules/patterns/PatternTokenBuilder.java:163

   * given token actually is a baseform.
   * @since 3.8 
   */
  public PatternTokenBuilder matchInflectedForms() {
    matchInflectedForms = true;
    return this;
  }
  
  public PatternToken build() {
    PatternToken patternToken;
    patternToken = new PatternToken(token, caseSensitive, regexp, matchInflectedForms);
    if (posTag != null) {
      patternToken.setPosToken(new PatternToken.PosToken(posTag, regexp, false));
    }
    if (isWhiteSpaceSet) {
      patternToken.setWhitespaceBefore(isWhiteSpaceBefore);
    }
    if (maxOccurrence < minOccurrence) {
      throw new IllegalArgumentException("minOccurrence must <= maxOccurrence: minOccurrence " + minOccurrence + ", maxOccurrence " + maxOccurrence);
    }
    if (tokenException != null) {
      patternToken.setStringPosException(tokenException, true, false, false, false, false, null, false, false, false);
    }
    patternToken.setMinOccurrence(minOccurrence);
    patternToken.setMaxOccurrence(maxOccurrence);
    patternToken.setNegation(negation);
    patternToken.setSkipNext(skip);
    patternToken.setInsideMarker(marker);
    return patternToken;
  }
}

View on GitHub (pinned to 2e990059ce)

Solutions

1. Set maxOccurrence to a value greater than or equal to minOccurrence before calling build()
2. Review the order of minOccurrence()/maxOccurrence() calls in the builder chain to make sure the last call does not shrink the range below the minimum
3. If the token is meant to be optional, use minOccurrence(0) with a suitable maxOccurrence instead of lowering maxOccurrence

When it happens

Trigger: Thrown at languagetool-core/src/main/java/org/languagetool/rules/patterns/PatternTokenBuilder.java:163 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of languagetool-org/languagetool@2e990059ce (2026-09-06). Data as JSON: /api/errors/f35dd983cba4422f. Report an issue: GitHub.