code: private function parseArray($isConst)
      {
          $start   = $this->lexer->token;
          $parseFn = $isConst ? function () {
              return $this->parseConstValue();
          } : function () {
              return $this->parseVariableValue();
          };
  
          return new ListValueNode(
              [
                  'values' => $this->any(Token::BRACKET_L, $parseFn, Token::BRACKET_R),
                  'loc'    => $this->loc($start),
              ]
          );
      }
docs: @param bool $isConst
  
  @return ListValueNode