A couple binary cursor questions

I am writing an ODBC driver for PostgreSQL.

I am using binary cursors. For most data types, I have no problems, but
for a couple I am confused. If someone could point me to the proper
documentation, source file or whatever, I would very much appreciate it.

The types I am having problems with are:
1. Currency data type. The binary pointer to the object, I assumed,
would point to either a NumericVar type (from Numeric.c) or to a Numeric
pointer from numeric.h. Neither of those assumptions are correct, as I
have looked carefully while tracing in the debugger.
So please, where do I find the correct definition for the binary object
handed back from Libpq when using a binary cursor with numeric data
type?

2. Array type objects. I cannot find a description of how to decipher
array objects from a binary cursor. Where can I find a definition of
how to do this.

I apologize for the intrusion, but I have been agonizing over this for
several days.