[Ur] callbacks from the c ffi

[Greg Samsa]

Hello,
I've been happily playing with Ur/Web and am pleased with the results so far.  One problem I am stuck on however is creating a callback from Ur, in other words, calling a C function that can then call Ur functions.  Unless I am misreading the docs this doesn't seem to be currently supported.

In looking at the generated C code, the api's generated are very straight forward, would it be possible to simply call those from a C function or would this have unintended consequences?

-Greg