gmpy/decimal interoperation

[Alex Martelli]

As things stand now (gmpy 1.01), an instance d of decimal.Decimal cannot
transparently become an instance of any of gmpy.{mpz, mpq, mpf}, nor
vice versa (the conversions are all possible, but a bit laborious, e.g.
by explicitly going through string-forms).

I'm thinking about possible ways to fix this, in whole or in part, but,
before I spend more time on this, I was wondering if there's anybody
else who'd be interested -- if so, maybe we can discuss which
conversions should happen implicitly (e.g., if you try to sum a Decimal
and an mpz, maybe the latter should implicitly become a Decimal, just
like an int would, so that the result is a Decimal) and which ones
should only happen on explicit request (e.g., gmpy.mpf(d) should produce
an mpf instance, just as calling gmpy.mpf on an int instance would).


Alex