API callbacks for completion

Hi,

   We have been building an LLDB driver for our language for a while
now, and something that we haven't found out yet how to do is
extending the completion mechanism for the commands we have added
(using the API). Is there a way to do that ? Is it possible to define
a callback that would be called to propose completions for every
argument of our commands ?

  To make it clearer: we are extending LLDB with commands to make it a
convenient debugger of OCaml native programs. We are using OCaml to
extend it, through a complete binding of LLDB's API in OCaml. We have
successfully added some new commands (mostly to inspect the memory
heap and print values with OCaml types), and we would like the
completion to work with specific arguments for OCaml. For example, one
of our new commands can list all the values available in an OCaml
module, so we would like to provide the list of modules to the
completion mechanism whenever the user is typing this command,
probably using a callback that would be associated with that command.
Any hint on how to do it ? Or would it be possible to extend the API
with such a command ?

--Fabrice