Re: Transform for pl/perl

On 04/24/2018 12:17 PM, Peter Eisentraut wrote:
> On 4/10/18 10:31, Dagfinn Ilmari Mannsåker wrote:
>> Also, it doesn't parse back in as jsonb either:
>>
>>     =# select jsonbnan()::text::json;
>>     ERROR:  invalid input syntax for type json
>>     DETAIL:  Token "NaN" is invalid.
>>     CONTEXT:  JSON data, line 1: NaN
>>
>> And it's inconsistent with to_jsonb():
>>
>>     =# select to_jsonb('nan'::numeric);
>>     ┌──────────┐
>>     │ to_jsonb │
>>     ├──────────┤
>>     │ "NaN"    │
>>     └──────────┘
>>
>> It would be highly weird if PL transforms (jsonb_plpython does the same
>> thing) let you create spec-violating jsonb values that don't round-trip
>> via jsonb_out/in.
> Yeah this is not good.  Is there a way to do this in a centralized way?
> Is there a function to check an internal jsonb value for consistency.
> Should at least the jsonb output function check and not print invalid
> values?
>


The output function fairly reasonably assumes that the jsonb is in a
form that would be parsed in by the input function. In particular, it
assumes that anything like a NaN will be stored as text and not as a
jsonb numeric. I don't think the transform should be doing anything
different from the input function.

There is the routine IsValidJsonNumber that helps - see among others
hstore_io.c for an example use.

cheers

andrew


-- 

Andrew Dunstan                https://www.2ndQuadrant.com
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