> The important optimization is the part that handles other TemplateIO
> objects using extend().  For the C implementation it might be more
> efficient to build a tree rather than always flattening it.

So the change you are proposing is in addition to making htmltext be a
string subclass, not a replacement for that change, right?  Sorry, I'm
clearly not ingesting caffeine at the required rate this morning...

I guess I don't see that change breaking anything that having the template
return htmltext didn't already do in.

jon