sbool tok_defaultArguments_debug = true;

// only one default argument per declaration for now

// example:

// static LS parse(S productions, S sentenceClass default "sentence", S input) { ... }

svoid tok_defaultArguments(LS tok) {

  while licensed {

    bool change;

    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;

      bool hasBody = tok_hasBody(tok, iClosing+2);

      //S args = joinSubList(tok, iOpening+2, iClosing-1);

      // function name

      int iName = iOpening-2;

      S name = get(tok, iName);

      bool isConstructor = eq(name, "*");

      if (!isConstructor && !isIdentifier(name))

        continue;

      int iAkas = tok_leftScanAkas(tok, iName);

      name = get(tok, iAkas);

      int iJavaxMods = tok_leftScanJavaxModifiers(tok, iAkas);

      int iType = isConstructor ? iJavaxMods : tok_leftScanType(tok, iJavaxMods);

      int iStart = tok_leftScanTypeArgsOpt(tok, iType);

      int iModsEnd = iStart;

      iStart = leftScanModifiers(tok, iModsEnd);

      Cl<S> modifiers = tok_modifiersLeftOf(tok, iModsEnd);

      if (!hasBody && !modifiers.contains("abstract"))

        modifiers.add("default");

      modifiers.remove("abstract");

      //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);

      LPairS args1withTypes = map tok_typeAndNameOfParam(args1);

      LPairS args2withTypes = map tok_typeAndNameOfParam(args2);

      LS type = subList(tok, iType-1, iName);

      bool isVoid = isConstructor || containsOneOf(codeTokens(type), javaxVoidAliases());

      if (eq(expr, "new")) expr = "new " + joinSubList(tok, iParamTypeStart, i-1) + "()";

      S rewrittenHead = spaceCombine(modifiers, joinSubList(tok, iModsEnd, iOpening+1)

        + joinWithComma(concatLists(args1, args2)) + ")";

      if (tok_defaultArguments_debug)

        printVars tok_defaultArguments(+expr, +_args1, +_args2, +args1, +args2, +type, +isVoid, +rewrittenHead, +args1withTypes, +args2withTypes);

      S forwardCall = (isVoid ? "" : "return ") + (isConstructor ? "this" : name) + "(" + 

        joinWithComma(concatLists(

          pairsB(args1withTypes),

          ll(expr),

          pairsB(args2withTypes))) + ");";

      clearTokens_reTok(tok, i+1, iEndOfExpr-1);

      tokPrepend_reTok(tok, iStart, rewrittenHead + " { "

        + forwardCall + " }\n");

      set change;

    }

    if (!change) break;

  }

}