_block example

foreach ($diff->getEdits() as $edit) {
      if ($edit->type == 'copy') {
        if (is_array($block)) {
          if (sizeof($edit->orig) <= $nlead + $ntrail) {
            $block[] = $edit;
          }
          else {
            if ($ntrail) {
              $context = array_slice($edit->orig, 0, $ntrail);
              $block[] = new DiffOpCopy($context);
            }
            $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block);
            $block = FALSE;
          }
        }
        $context = $edit->orig;
      }
      else {
        if (!is_array($block)) {
          $context = array_slice($context, sizeof($context) - $nlead);
          $x0 = $xi - sizeof($context);
          $y0 = $yi - sizeof($context);
          $block = [];
          

/* We have less lines in the block than we want for * context => keep the whole block. */
                        $block[] = $edit;
                    } else {
                        if ($ntrail) {
                            /* Create a new block with as many lines as we need * for the trailing context. */
                            $context = array_slice($edit->orig, 0, $ntrail);
                            $block[] = new Text_Diff_Op_copy($context);
                        }
                        /* @todo */
                        $output .= $this->_block($x0, $ntrail + $xi - $x0,
                                                 $y0, $ntrail + $yi - $y0,
                                                 $block);
                        $block = false;
                    }
                }
                /* Keep the copy block as the context for the next block. */
                $context = $edit->orig;
            } else {
                /* Don't we have any diff blocks yet? */
                if (!is_array($block)) {
                    /* Extract context lines from the preceding copy block. */