code: public function handle(Context $context)
      {
          $beginArray = new StructuralChar(array("["));
          $beginArray->handle($context);
          
          if ($context->current() === "]") {
              $endArray = new StructuralChar(array("]"));
              $endArray->handle($context);
              $this->result = array();
              return;
          }
          
          $result = array();
          while (true) {
              $value = new Value();
              $value->handle($context);
              $result[] = $value->getResult();
              
              $struct = new StructuralChar(array(",", "]"));
              $struct->handle($context);
              if ($struct->getResult() === "]") {
                  $this->result = $result;
                  break;
              }
          }
      }
docs: 現在の Context から配列部分を読み込みます.
  
  @param Context $context