code: public function parseFor() {
          // consume required tokens
          $for_open_token = $this->pop('FOR_OPEN');
          $this->currLine++;
  
          // create output so far
          $output = '$for_index = 0; foreach(' . 
              $for_open_token[1][1] . ' as ' . 
              $for_open_token[1][0] . ') {' . "\n";
  
          while(true) {
              list($type, $value) = $this->peek();
  
              if($type == 'FOR_CLOSE') {
                  // pop the element, and add the value
                  $this->pop();
                  $output .= '$for_index++; }' . "\n";
                  $this->currLine++;
                  break;
              } else {
                  $output .= $this->parseExpression();
              }
          }
  
          return $output;
      }
docs: Parses a FOR expression