Are there iOS/iPad apps that work well to edit XML?

I'm surprised that a google search doesn't turn up dozens of XML editors for ipad. All I can find are generic code text editors that happen to "support" XML. Well duh.

I'm looking for an ipad app that lets me edit arbitrary XML as something other than a generic text box with code completion. It could at least give me an expandable tree view of nested tags for example. And it could allow me to add a child tag or duplicate an existing one. Or do a structured search of the document based on identified symbols, or even some automated manipulation based on symbols. One of the main impetuses for creating XML in the first place was to enable a diversity of kinds of manipulation tools.

Does anything exist on ipad specifically for editing XML?

Diet Coda, and Koder support XML syntax highlighting also. I use them both for editing XML, JSON, etc.