private RegExp expandMacro()

in jflex/src/main/java/jflex/core/Macros.java [141:209]
54 lines of code
22 McCabe index (conditional complexity)

  private RegExp expandMacro(String name, RegExp definition) throws MacroException {

    // Out.print("checking macro "+name);
    // Out.print("definition is "+definition);

    switch (definition.type) {
      case sym.BAR:
      case sym.CONCAT:
        RegExp2 binary = (RegExp2) definition;
        binary.r1 = expandMacro(name, binary.r1);
        binary.r2 = expandMacro(name, binary.r2);
        return definition;

      case sym.STAR:
      case sym.PLUS:
      case sym.QUESTION:
      case sym.BANG:
      case sym.TILDE:
        RegExp1 unary = (RegExp1) definition;
        unary.content = expandMacro(name, (RegExp) unary.content);
        return definition;

      case sym.MACROUSE:
        String usename = (String) ((RegExp1) definition).content;

        if (Objects.equals(name, usename))
          throw new MacroException(ErrorMessages.get(MACRO_CYCLE, name));

        RegExp usedef = getDefinition(usename);

        if (usedef == null) {
          throw new MacroException(
              ErrorMessages.get(ErrorMessages.MACRO_DEF_MISSING, usename, name));
        }

        markUsed(usename);

        return expandMacro(name, usedef);

      case sym.STRING:
      case sym.STRING_I:
      case sym.CHAR:
      case sym.CHAR_I:
      case sym.PRIMCLASS:
      case sym.PRECLASS:
      case sym.UNIPROPCCLASS:
        return definition;

      case sym.CCLASS:
      case sym.CCLASSNOT:
        RegExp1 cclass = (RegExp1) definition;
        List<RegExp> classes = new ArrayList<>();
        for (RegExp regexp : (List<RegExp>) cclass.content) {
          classes.add(expandMacro(name, regexp));
        }
        cclass.content = classes;
        return cclass;

      case sym.CCLASSOP:
        RegExp2 cclassOp = (RegExp2) ((RegExp1) definition).content;
        cclassOp.r1 = expandMacro(name, cclassOp.r1);
        cclassOp.r2 = expandMacro(name, cclassOp.r2);
        return definition;

      default:
        throw new MacroException(
            "unknown expression type " + definition.typeName() + " in macro expansion");
    }
  }