Create typed-mutable extension?

Assuming that we adopt the XQuery Update Facility mods for our mutable API, the 
question of whether we should also provide a typed-mutable extension arises.

This provides three additional methods, not found in the current base mutable 
api: revalidate, removeType, and setToUntyped (I don't know what the difference 
is between those two last, though there is one).

One complication is that this raises the question: what is the relationship 
between typed and untyped APIs in a bridge?  If we provide "revalidate" in a 
typed-mutable extension, could this be used on a hitherto-unvalidated untyped 
tree to turn it into a typed one?  Should there be a "validate" on TypedContext 
to permit a well-known path from untyped to typed?  (the path from typed to 
untyped is easy, since typed extends untyped: just use the typed tree as if it 
were untyped).

Original issue reported on code.google.com by aale...@gmail.com on 3 Dec 2010 at 9:06

sshyran / genxdm

Create typed-mutable extension? #38