Re: NaN support in NUMERIC data type

Sam Mason <sam(at)samason(dot)me(dot)uk> writes:
> I've just noticed that the NUMERIC input function special cases NaN
> values differently to the floating point input functions. For example
> the following are all accepted (on my system anyway):

> SELECT 'NaN'::float8;
> SELECT ' NaN'::float8;
> SELECT 'NaN '::float8;
> SELECT '+NaN'::float8;
> SELECT '-NaN'::float8;

> whereas only the first is OK for numeric. Is this deliberate?

Well, the +- part must be an artifact of your strtod() implementation;
our own code isn't doing anything to accept that. I think it's pretty
bogus --- NaNs do not have signs.

IIRC, the explicit support for leading/trailing spaces is something that
we added in float8in long after numeric_in was written, and I think just
nobody thought about numeric at the time. But it's clearly inconsistent
to allow spaces around a regular value but not a NaN.

Possibly the logic for leading/trailing spaces could be pulled out
of set_var_from_str and executed in numeric_in instead?

regards, tom lane