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 -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
