On Tue, May 1, 2012 at 9:05 AM, Merlin Moncure
<mmoncure@gmail.com> wrote:
On Tue, May 1, 2012 at 10:49 AM, Joey Adams <
joeyadams3.14159@gmail.com> wrote:
> On Tue, May 1, 2012 at 8:02 AM, Hannu Krosing <
hannu@2ndquadrant.com> wrote:
>> Hi hackers
>>
>> After playing around with array_to_json() and row_to_json() functions a
>> bit it I have a question - why do we even have 2 variants *_to_json()
>
> Here's the discussion where that decision was made:
>
>
http://archives.postgresql.org/pgsql-hackers/2012-01/msg01339.php >
> To quote:
>
>>>> why not call all these functions 'to_json' and overload them?
>>>
>>> I don't honestly feel that advances clarity much. And we might want to overload each at some stage with options that are specific to the datum type. We have various foo_to_xml() functions now.
>>
>> -1
>>
>> older proposal is more consistent with xml functions
>
> The most compelling argument I see here is the one about options
> specific to the datum type.
for example supports multiple argument versions depending on the input
type.
> * If the JSON type does not yet support, say, converting from a
> number, it will be apparent from the names and types of the functions,
> rather than being a hidden surprise. On the other hand, array_to_json
> and composite_to_json already convert ANY values to JSON, so this
> doesn't matter, anyway.
I am away from base on a consulting assignment all this week, so my connectivity and time are severely limited, and I don't have time to respond in depth.
Let me just point out two things. First, we are approaching a beta release. The time for changing this is long since gone, IMNSHO.
Second, RFC 4627 is absolutely clear: a valid JSON value can only be an object or an array, so this thing about converting arbitrary datum values to JSON is a fantasy. If anything, we should adjust the JSON input routines to disallow anything else, rather than start to output what is not valid JSON.
cheers
andrew
