sbool tok_defaultArguments_debug = true;

// only one default argument per declaration for now
// example:
// static LS recursiveProbabilisticParse(S productions, S sentenceClass default "sentence", S input) { ... }
svoid tok_defaultArguments(LS tok) {
  for (int i : jfindAll_reversed(tok, "<id> default", tokCondition {
    ret !eqGetOneOf(tok, i-1, "ifclass", "ifdef", "ifndef")
      && !isJavaModifier(_get(tok, i+1));
  })) {
    int iOpening = lastIndexOf(tok, i, "(");
    int iClosing = findEndOfBracketPart2(tok, iOpening)-1;
    //S args = joinSubList(tok, iOpening+2, iClosing-1);
    
    // function name
    int iName = iOpening-2;
    S name = get(tok, iName);
    if (!isIdentifier(name)) continue;
    
    int iType = tok_leftScanType(tok, iName);
    int iStart = tok_leftScanTypeArgsOpt(tok, iType);
    iStart = leftScanModifiers(tok, iStart);
    //print("Found method head: " + joinSubList(tok, iStart, iClosing+1));
    int iEndOfExpr = tok_findEndOfExpression(tok, i+4)+1; // should point at comma or closing bracket
    S expr = joinSubList(tok, i+4, iEndOfExpr);
    int iParamTypeStart = tok_leftScanType(tok, i);
    LS _args1 = subList(tok, iOpening+1, iParamTypeStart);
    LS _args2 = subList(tok, iEndOfExpr+1, iClosing+2);
    LS args1 = tok_parseArgsDeclList2(_args1);
    LS args2 = tok_parseArgsDeclList2(_args2);
    LS type = subList(tok, iType-1, iName);
    bool isVoid = containsOneOf(codeTokens(type), javaxVoidAliases());
    if (eq(expr, "new")) expr = "new " + joinSubList(tok, iParamTypeStart, i-1) + "()";
    
    S modifiers = join(listMinus(subList(tok, iStart, iType), "abstract"));
    
    S rewrittenHead = 
      modifiers
      + joinSubList(tok, iType, iOpening+1)
      + joinWithComma(concatLists(args1, args2)) + ")";
      
    if (tok_defaultArguments_debug)
      printVars tok_defaultArguments(+expr, +_args1, +_args2, +args1, +args2, +type, +isVoid, +rewrittenHead);
    
    clearTokens_reTok(tok, i+1, iEndOfExpr-1);
    tokPrepend_reTok(tok, iStart, rewrittenHead + " { "
      + (isVoid ? "" : "return ") + name + "(" + 
        joinWithComma(concatLists(
          map tok_lastIdentifier(args1),
          ll(expr),
          map tok_lastIdentifier(args2))) + "); }\n");
 }
}

Began life as a copy of #1027996