Re: [PATCH] Add get_bytes() and set_bytes() functions

On Wed, Aug 14, 2024 at 05:39:32PM +0200, Joel Jacobson wrote:
> On Wed, Aug 14, 2024, at 16:43, David Fetter wrote:
> >> I also think it would be nice to provide these convenience functions:
> >> to_bytes(bigint) -> bytea
> >> from_bytes(bytea) -> bigint
> >
> > Along with these, would it make sense to have other forms of these
> > that won't choke at 63 bits, e.g. NUMERIC or TEXT?
>
> I wonder what would be good names for such functions though?

decimal_to_bytes(numeric), decimal_to_bytes(text) on one side
decimal_from_bytes(bytea, typeoid)

Naming Things™ is one of the hard problems in computer science. Bad
joke that includes cache coherency and off-by-one included by
reference.

> Since NUMERIC can have decimal digits, and since BYTEA can already be casted to
> TEXT, which will just be \x followed by the hex digits, maybe such names should
> include "integer" or some other word, to indicate what is being returned?
>
> It's already quite easy to convert to NUMERIC though,
> for users who are aware of tricks like this:
> SELECT ('0x'||encode('\xCAFEBABEDEADBEEF'::bytea,'hex'))::numeric;
> numeric
> ----------------------
> 14627333968688430831
> (1 row)
>
> But, I think it would be better to provide functions,
> since many users probably have to google+stackoverflow or gpt
> to learn such tricks, which are not in the official documentation.

As usual, I see "official documentation lacks helpful and/or
non-obvious examples" as a problem best approached by making good the
lack. I am aware that my ideas about pedagogy, documentation, etc. are
not shared universally, but they're widely shared by people whose main
interaction with documents is trying to get help from them.

Best,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778