Re: BUG #8355: PL/Python 3 can't convert infinity to PostgreSQL's value

I based on the documentation of PostgreSQL  (http://www.postgresql.org/docs/9.2/static/datatype-numeric.html#DATATYPE-FLOAT) which says about 'Infinity' and '-Infinity' and doesn't mention other possible spellings, including 'inf'.
And on my installation of 9.2.4 'inf' doesn't work too (as I supposed according to documentation):

        SELECT 'inf'::float8

        ERROR:  invalid input syntax for type double precision: "inf"
        LINE 2: SELECT 'inf'::float8

According to Python's documentation (http://docs.python.org/2/library/stdtypes.html#typesnumeric), handle of infinities and NaNs was added in 2.6. At least this works in 2.7.1:

        Python 2.7.1 (r271:86832, Apr  1 2013, 01:27:27) [MSC v.1600 64 bit (AMD64)] on win32
        Type "help", "copyright", "credits" or "license" for more information.
>>>  float('inf')
        inf
>>>  float('infinity')
        inf
>>>  float('+inf')
        inf
>>>  float('-inf')
        -inf

So, Python is honest in this way. And, C99 says that style of representation ('inf' or 'infinity') is implementation-defined, so it is all OK with modern Python.

>  We already backstop strtod() for these cases:
>
>          NaN
>          Infinity
>          -Infinity
>
>  but the wording of the spec clearly requires +Infinity as well as the
>  forms with just "inf".  (It also appears to require +/- NaN to be
>  accepted, but I have no idea what that would mean and suspect it to
>  be a thinko.)

As I can judge, signed NaNs are from the same world as signed zeros and signed infinities. Strictly speaking: (-0)/(+0) is -NaN, (-inf)/(+inf) is -NaN, and so on.
I think that PostgreSQL's ability to handle signed zeros (and all other rare stuff) depends on compiler used. Google says me that '-NaN' exists in modern glibc. I don't know about MSVC. My Python accepts '-nan' as input, but doesn't give me '-NaN' as output.
So, I think it would be good if '-NaN' and other forms were workable.

--
Best regards,
Basil Peace