code: private void parseLiteral() {
  
          AtomicValue atomic;
  
          if (mToken.getType() == TokenType.VALUE || mToken.getType() == TokenType.POINT) {
              // is numeric literal
              atomic = parseIntegerLiteral();
          } else {
              // is string literal
              assert (mToken.getType() == TokenType.DBL_QUOTE || mToken.getType() == TokenType.SINGLE_QUOTE);
              atomic = parseStringLiteral();
          }
  
          mPipeBuilder.addLiteral(mRTX, atomic);
  
      }
docs: Parses the the rule Literal according to the following production rule:
  <p>
  [42] Literal ::= NumericLiteral | StringLiteral .
  </p>