Dom\HTMLDocument: prototype.js like DOM-Traversal

Description

Hi,

I just started diving into the new DOM features that came with PHP 8.4, and wondered if it's possible (and/or in the focus of HTMLDocument) to add some of Prototype's DOM traversal and enumerable features. Prototype may have vanished from the web, but its intuitive traversal methods are to this day unmatched and made working on a HTML tree a breeze.

I've implemented this in PHP before, but it was a pain fighting against the quirks of DOMDocument, XML and the countless DOMNode subclasses, it felt very messy to begin with.

Now before I attempt to implement this again in userland with HTMLDocument: is there any chance to even consider such features, or is this out of focus?

まず、PHP 8.4 で導入された HTMLDocument の DOM 機能を読み、要求されているトラバーサルおよび列挙の動作を、リンクされている Prototype APIs と比較します。次に、chillerlan/php-prototype-dom の既存の userland 実装を確認し、これが HTMLDocument に含まれるべきか、またどの機能範囲を完了とみなすかを issue の議論から判断します。