docs: Expression XreadValueExpressionPrimary() {
  
          Expression e;
  
          e = XreadSimpleValueExpressionPrimary();
  
          if (e != null) {
              return e;
          }
  
          if (token.tokenType == Tokens.OPENBRACKET) {
              read();
  
              e = XreadValueExpression();
  
              readThis(Tokens.CLOSEBRACKET);
          } else {
              return null;
          }
  
          return e;
      }