[PATCH v2 5/8] box: rework field_def and tuple_compare to work with mp_field_type instead of mp_type

[Konstantin Osipov]

* Serge Petrenko <sergepetrenko at tarantool.org> [19/08/08 15:01]:
> This a preparation for adding decimal fields and decimal comparators. It
> will be needed, since newly introduced user types, such as decimal, will
> all share a single mp_type, and we want to avoid additional checks for
> MP_EXT subtypes.

I think this is confusing as hell. This new enum doesn't represent
anything, it's neither field_type (otherwise it would be enum
field_type) nor mp_type.

Sounds like it is a strange "weight" or "code point" calculated for 
a Cartesian product of field_type, mp_type and mp_ext type. Well,
if you want to optimize the code to look at this code point, let's
at least make it clear that it's not a type, but an optimization
technique we use.

Or let's just look at a combination of field_type and mp_type and
not introduce this strange entity just to preserve a few switches
around.


-- 
Konstantin Osipov, Moscow, Russia