Re: Proposal: variant of regclass

On Tue, Jan 14, 2014 at 9:28 AM, Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp> wrote:
> Here is the patch to implement to_regclass, to_regproc, to_regoper,
> and to_regtype.

+ static Datum regclass_guts(char *class_name_or_oid, bool raiseError);

Minor bikeshedding, a lot of code currently uses an argument named
"missing_ok" for this purpose (with inverse meaning of course). Any
reasons why you chose "raiseError" instead?

I only had a brief look at the patch, so maybe I'm missing something.
But I don't think you should create 3 variants of these functions:
* parseTypeString calls parseTypeString_guts with false
* parseTypeStringMissingOk calls parseTypeString_guts with true
* parseTypeString_guts

And this is just silly:

if (raiseError)
parseTypeString(typ_name_or_oid, &result, &typmod);
else
parseTypeStringMissingOk(typ_name_or_oid, &result, &typmod);

Just add an argument to parseTypeString and patch all the callers.

> if requested object is not found,
> returns InvalidOid, rather than raises an error.

I thought the consensus was that returning NULL is better than
InvalidOid? From an earlier message:

On Thu, Dec 5, 2013 at 5:25 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> Another advantage of this approach is that, IIUC, type input functions
> can't return a NULL value. So 'pg_klass'::regclass could return 0,
> but not NULL. On the other hand, toregclass('pg_klass') *could*
> return NULL, which seems conceptually cleaner.

Regards,
Marti