Michel Pelletier <pelletier.michel@gmail.com> writes:
> ...
> I agree it makes sense to have more use cases before making deeper
> changes.  I only work with expanded forms,  but need to call wait() to
> pre-expand the object to avoid multiple expansions in functions that can
> take the same object in multiple parameters.

Hmm.  I agree that the wait() call is a bit ugly, but there are at
least two things that seem worth looking into before we go so far
as inventing type-support infrastructure:

2. If the problem is primarily with passing the same object to
multiple parameters of a function, couldn't you detect and optimize
that within the function?  It would be messier than just blindly
applying DatumGetWhatever() to each parameter position; but with a
bit of thought I bet you could create some support logic that would
hide most of the mess.