code: private function parseIf() {
          // consume required tokens
          $if_open = $this->pop('IF_OPEN');
          $output = 'if(' . $if_open[1] . ') {' . "\n";
          $this->currLine++;
  
          $seeking = true;
          while($seeking) {
              list($type, $value) = $this->peek();
  
              switch($type) {
              case 'IF_CLOSE':
                  $this->pop();
                  $output .= "}\n";
                  $seeking = false;
                  $this->currLine++;
                  break;
              case 'ELSE':
                  $this->pop();
                  $output .= "} else {\n";
                  $this->currLine++;
                  break;
              case 'ELSE_IF':
                  $token = $this->pop();
                  $output .= '} elseif(' . $token[1] . ") {\n";
                  $this->currLine++;
                  break;
              default:
                  $output .= $this->parseExpression();
                  break;
              }
          }
  
          return $output;
      }
docs: Parses an IF expression