More detailed examples of ffi

[dsmich]

Greetings Guilers!

The other day, aidalgol and I were chatting on irc about the new ffi.  The 
question came up about how to define and access nested structures.  I couldn't 
tell from reading the manual if it can be done.

Could some more complex examples be put in the manual that more fully exposes 
the capabilities of the ffi?

Thanks!
  -Dale