WP_HTML_Processor::seek( string $bookmark_name ): bool

5534	public function seek( $bookmark_name ): bool {5535		// Flush any pending updates to the document before beginning.5536		$this->get_updated_html();5537 5538		$actual_bookmark_name = "_{$bookmark_name}";5539		$processor_started_at = $this->state->current_token5540			? $this->bookmarks[ $this->state->current_token->bookmark_name ]->start5541			: 0;5542		$bookmark_starts_at   = $this->bookmarks[ $actual_bookmark_name ]->start;5543		$direction            = $bookmark_starts_at > $processor_started_at ? 'forward' : 'backward';5544 5545		/*5546		 * If seeking backwards, it's possible that the sought-after bookmark exists within an element5547		 * which has been closed before the current cursor; in other words, it has already been removed5548		 * from the stack of open elements. This means that it's insufficient to simply pop off elements5549		 * from the stack of open elements which appear after the bookmarked location and then jump to5550		 * that location, as the elements which were open before won't be re-opened.5551		 *5552		 * In order to maintain consistency, the HTML Processor rewinds to the start of the document5553		 * and reparses everything until it finds the sought-after bookmark.5554		 *5555		 * There are potentially better ways to do this: cache the parser state for each bookmark and5556		 * restore it when seeking; store an immutable and idempotent register of where elements open5557		 * and close.5558		 *5559		 * If caching the parser state it will be essential to properly maintain the cached stack of5560		 * open elements and active formatting elements when modifying the document. This could be a5561		 * tedious and time-consuming process as well, and so for now will not be performed.5562		 *5563		 * It may be possible to track bookmarks for where elements open and close, and in doing so5564		 * be able to quickly recalculate breadcrumbs for any element in the document. It may even5565		 * be possible to remove the stack of open elements and compute it on the fly this way.5566		 * If doing this, the parser would need to track the opening and closing locations for all5567		 * tokens in the breadcrumb path for any and all bookmarks. By utilizing bookmarks themselves5568		 * this list could be automatically maintained while modifying the document. Finding the5569		 * breadcrumbs would then amount to traversing that list from the start until the token5570		 * being inspected. Once an element closes, if there are no bookmarks pointing to locations5571		 * within that element, then all of these locations may be forgotten to save on memory use5572		 * and computation time.5573		 */5574		if ( 'backward' === $direction ) {5575 5576			/*5577			 * When moving backward, stateful stacks should be cleared.5578			 */5579			foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {5580				$this->state->stack_of_open_elements->remove_node( $item );5581			}5582 5583			foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {5584				$this->state->active_formatting_elements->remove_node( $item );5585			}5586 5587			/*5588			 * **After** clearing stacks, more processor state can be reset.5589			 * This must be done after clearing the stack because those stacks generate events that5590			 * would appear on a subsequent call to `next_token()`.5591			 */5592			$this->state->frameset_ok                       = true;5593			$this->state->stack_of_template_insertion_modes = array();5594			$this->state->head_element                      = null;5595			$this->state->form_element                      = null;5596			$this->state->current_token                     = null;5597			$this->current_element                          = null;5598			$this->element_queue                            = array();5599 5600			/*5601			 * The absence of a context node indicates a full parse.5602			 * The presence of a context node indicates a fragment parser.5603			 */5604			if ( null === $this->context_node ) {5605				$this->change_parsing_namespace( 'html' );5606				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_INITIAL;5607				$this->breadcrumbs           = array();5608 5609				$this->bookmarks['initial'] = new WP_HTML_Span( 0, 0 );5610				parent::seek( 'initial' );5611				unset( $this->bookmarks['initial'] );5612			} else {5613
When	Instructions	Calls it makes
`$direction !== "backward" && !->next_token()`	25–40	`->get_updated_html(), ->is_virtual(), ->next_token()`
`$direction !== "backward" && !->is_virtual() && $bookmark_starts_at === false`	30–37	`->get_updated_html(), ->is_virtual()`
`$direction === "backward" && !->next_token()`	81–98	`->get_updated_html(), ->walk_up(), ->walk_up(), ->change_parsing_namespace(), ::seek(), ->is_virtual(), ->next_token()`
`$direction === "backward" && !->is_virtual() && $bookmark_starts_at === false`	86–95	`->get_updated_html(), ->walk_up(), ->walk_up(), ->change_parsing_namespace(), ::seek(), ->is_virtual()`
`$direction === "backward" && !->next_token()`	97–119	`->get_updated_html(), ->walk_up(), ->walk_up(), ->push(), ->change_parsing_namespace(), ->reset_insertion_mode_appropriately(), array_slice(), ::seek(), ->is_virtual(), ->next_token()`
`$direction === "backward" && !->is_virtual() && $bookmark_starts_at === false`	102–116	`->get_updated_html(), ->walk_up(), ->walk_up(), ->push(), ->change_parsing_namespace(), ->reset_insertion_mode_appropriately(), array_slice(), ::seek(), ->is_virtual()`
PHP	Compiled	Executed	Branches	Notes
8.6-dev	158	25–119	13
8.5	158	25–119	13
8.4	158	25–119	13
8.3	158	25–119	13
8.2	158	25–119	13
8.1	158	25–119	13	2 fewer instructions than PHP 7.4
7.4	160	25–121	13