docs: private boolean buildRegexpParser() {
  
      // Convert wildcard string mask to regular expression
      String regexp = convertWildcardExpressionToRegularExpression(mStringMask);
  
      if (regexp == null) {
        out.println(DebugUtil.getPrefixErrorMessage(this)
                    + "irregularity in regexp conversion - now not able to parse any strings, all strings will be rejected!");
        return false;
      }
  
      // Instantiate a regular expression parser
      try {
        mRegexpParser = Pattern.compile(regexp);
      }
      catch (PatternSyntaxException e) {
        if (mDebugging) {
          out.println(DebugUtil.getPrefixErrorMessage(this) + "RESyntaxException \"" + e.getMessage()
                      + "\" caught - now not able to parse any strings, all strings will be rejected!");
        }
        if (mDebugging) {
          e.printStackTrace(System.err);
        }
        return false;
      }
      if (mDebugging) {
        out.println(DebugUtil.getPrefixDebugMessage(this) + "regular expression parser from regular expression " + regexp
                    + " extracted from wildcard string mask " + mStringMask + ".");
      }
      return true;
    }