Re: What happened to the is_ family of functions proposal?

Alvaro Herrera <alvherre@commandprompt.com> writes:
>> On Tue, Sep 21, 2010 at 11:49 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> The problem here is that putting the exception handling in C doesn't
>>> make things any better:

> So we could refactor the input functions so that there's an internal
> function that returns the accepted datum in the OK case and an ErrorData
> for the failure case.

This makes the untenable assumption that there are no elog(ERROR)s in
the "internal" input function *or anything it calls*.  Short of truly
massive restructuring, including uglifying many internal APIs to have
error return codes instead of allowing elog within the callee, you will
never make this work for anything more complicated than say float8in().
        regards, tom lane