Re: int4 or int32

Peter Eisentraut <peter_e@gmx.net> writes:
> Which one of these should we use?
> int4 is a data type, int32 isn't.  c.h has DatumGetInt8, but no
> DatumGetInt64; it also has DatumGetInt32 but no DatumGetInt4.  fmgr has
> PG_GETARG_INT32 et al.  Inconsistency everywhere.

The original convention was to use int4 etc at the SQL level, int32 etc
at the C level.  However the typedefs int4 etc have to be visible in
the include/catalog/pg_*.h headers, and so there's been a certain amount
of leakage of those typedefs into the C sources.

I think that int32 etc are better choices at the C level because of
the well-established precedent for naming integer types after numbers
of bits in C code.  I don't feel any strong urge to go around and
change the existing misusages, but if you want to, I won't object.

I also have to plead guilty to having changed all the float-datatype
code to use float4 and float8 recently.  This was mainly because the
existing typedefs for float32 and float64 had a built-in assumption
that these types would always be pass-by-reference, and I wanted to
abstract the code away from that assumption.  We can't touch those
typedefs for a release or three (else we'll break existing user
functions written in C), so switching to the SQL-level names seemed
like the best bet.  But it's not real consistent with the integer-type
naming conventions :-(
        regards, tom lane