WP_HTML_Processor::get_current_depth(): int

Example: $processor = WP_HTML_Processor::create_fragment( '<div><p></p></div>' ); // The processor starts in the BODY context, meaning it has depth from the start: HTML > BODY. 2 === $processor->get_current_depth(); // Opening the DIV element increases the depth. $processor->next_token(); 3 === $processor->get_current_depth(); // Opening the P element increases the depth. $processor->next_token(); 4 === $processor->get_current_depth(); // The P element is closed during next_token() so the depth is decreased to reflect that. $processor->next_token(); 3 === $processor->get_current_depth();