class PostReformPortugueseCompoundRule extends AbstractCompoundRule {

  private static final Pattern HYPHEN = compile("-");
  private static final Pattern VOWEL = compile("(?i).+[aeiou]$");
  private static final Pattern RS = compile("(?i)^[rs].+");

  private static volatile CompoundRuleData compoundData;

  public PostReformPortugueseCompoundRule(ResourceBundle messages, Language lang, UserConfig userConfig) throws IOException {    
    super(messages, lang, userConfig,
            "Esta palavra é hifenizada.",
            "Esta palavra é composta por justaposição.",
            "Esta palavra pode ser composta por justaposição ou hifenizada.",
            "Este conjunto forma uma palavra composta.");
    super.setCategory(Categories.COMPOUNDING.getCategory(messages));
    setLocQualityIssueType(ITSIssueType.Grammar);
    useSubRuleSpecificIds();
  }

  @Override
  public String getId() {
    return "PT_COMPOUNDS_POST_REFORM";
  }

  @Override
  public String getDescription() {
    return "Erro na formação da palavra composta \"$match\"";
  }

  @Override
  public URL getUrl() {
    return Tools.getUrl("https://pt.wikipedia.org/wiki/Lista_das_alterações_previstas_pelo_acordo_ortográfico_de_1990");
  }

  @Override
  public CompoundRuleData getCompoundRuleData() {
    CompoundRuleData data = compoundData;
    if (data == null) {
      synchronized (PostReformPortugueseCompoundRule.class) {
        data = compoundData;
        if (data == null) {
          compoundData = data = new CompoundRuleData("/pt/post-reform-compounds.txt");
        }
      }
    }

    return data;
  }

  // This override is here to account for Portuguese transformations required as per the latest orthography:
  // ultra + som  => ultrassom (with <s> turned into <ss> to keep the sound).
  @Override
  public String mergeCompound(String str, boolean uncapitalizeMidWords) {<FILL_FUNCTION_BODY>}
}

    String[] stringParts = HYPHEN.matcher(str).replaceAll(" ").split(" ");
    StringBuilder sb = new StringBuilder();
    for (int k = 0; k < stringParts.length; k++) {
      if (k == 0) {
        sb.append(stringParts[0]);
      } else {
        // if previous element ends in vowel and current one starts with <r> or <s>, we need to double the letter into
        // a digraph that creates the sound we want
        if (VOWEL.matcher(stringParts[k - 1]).matches() && RS.matcher(stringParts[k]).matches()) {
          stringParts[k] = stringParts[k].charAt(0) + stringParts[k];
        }
        sb.append(uncapitalizeMidWords ? StringUtils.uncapitalize(stringParts[k]) : stringParts[k]);
      }
    }
    return sb.toString();
  
<methods>public void <init>(java.util.ResourceBundle, org.languagetool.Language, org.languagetool.UserConfig, java.lang.String, java.lang.String, java.lang.String) throws java.io.IOException,public void <init>(java.util.ResourceBundle, org.languagetool.Language, org.languagetool.UserConfig, java.lang.String, java.lang.String, java.lang.String, java.lang.String) throws java.io.IOException,public int estimateContextForSureMatch() ,public abstract org.languagetool.rules.CompoundRuleData getCompoundRuleData() ,public abstract java.lang.String getDescription() ,public abstract java.lang.String getId() ,public boolean isMisspelled(java.lang.String) throws java.io.IOException,public org.languagetool.rules.RuleMatch[] match(org.languagetool.AnalyzedSentence) throws java.io.IOException,public java.lang.String mergeCompound(java.lang.String, boolean) ,public void useSubRuleSpecificIds() <variables>private static final java.util.regex.Pattern DASHES,private static final java.util.regex.Pattern DIGIT,static final int MAX_TERMS,private static final java.util.regex.Pattern WHITESPACE,private static final java.util.regex.Pattern WHITESPACE_DASH,protected final non-sealed org.languagetool.Language lang,protected final non-sealed org.languagetool.LinguServices linguServices,protected boolean sentenceStartsWithUpperCase,private final non-sealed java.lang.String shortDesc,protected boolean subRuleSpecificIds,private final non-sealed java.lang.String withHyphenMessage,private final non-sealed java.lang.String withOrWithoutHyphenMessage,private final non-sealed java.lang.String withoutHyphenMessage