[whatwg] Stability of tokenizing/dom algorithms

[Edward Z. Yang]

Ian Hickson wrote:
> In general you should be able to just implement what the spec says and 
> then either leave the HTML5 support in (it's unlikely to cause any harm) 
> or just comment out the support for the new elements, that should be 
> relatively easy.

Right, this is mostly what I intended to do. But from what I can tell,
there's a difference between the design philosophies of HTML 5 and XHTML
2.0; XHTML tries to make everything "extensible" and able to be imported
from other places, while HTML 5 attempts to document what exists, and
then make sensible additions as necessary. HTML 5 pragmatism makes sense
for a user-agent, but the XHTML extensibility is useful for a sanitizer,
which doesn't actually have to render anything and needs to support
multiple dialects and variants.

Cheers,
Edward