code: function parseArguments() {
          var args = [];
  
          expect('(');
  
          if (!match(')')) {
              while (index < length) {
                  args.push(parseExpression());
                  if (match(')')) {
                      break;
                  }
                  expect(',');
              }
          }
  
          expect(')');
  
          return args;
      }
docs: 11.2 Left-Hand-Side Expressions