On Fri, Feb 22, 2013 at 11:50 AM, David E. Wheeler
<da...@justatheory.com> wrote:
> On Feb 22, 2013, at 9:37 AM, Robert Haas <robertmh...@gmail.com> wrote:
>
>> What I think is NOT tolerable is choosing a set of short but arbitrary
>> names which are different from anything that we have now and
>> pretending that we'll want to use those again for the next data type
>> that comes along. That's just wishful thinking. Programmers who
>> believe that their decisions will act as precedent for all future code
>> are almost inevitably disappointed. Precedent grows organically out
>> of what happens; it's very hard to create it ex nihilo, especially
>> since we have no clear idea what future data types we'll likely want
>> to add. Sure, if we add something that's just like JSON but with a
>> few extra features, we'll be able to reuse the names no problem. But
>> that's unlikely, because we typically resist the urge to add things
>> that are too much like what we already have. The main reason we're
>> adding JSON when we already have hstore is because JSON has become
>> something of a standard. We probably WILL add more "container" types
>> in the future, but I'd guess that they are likely to be as different
>> from JSON as JSON is from XML, or from arrays. I'm not convinced we
>> can define a set of semantics that are going to sweep that broadly.
>
> Maybe. I would argue, however, that a key/value-oriented data type will
> always call those things "keys" and "values". So keys() and vals() (or
> get_keys() and get_vals()) seems pretty reasonable to me.
>
> Anyway, back to practicalities, Andrew last posted:
>
>> I am going to go the way that involves the least amount of explicit casting
>> or array construction. So get_path() stays, but becomes non-variadic. get()
>> can take an int or variadic text[], so you can do:
>>
>> get(myjson,0)
>> get(myjson,'f1')
>> get(myjson,'f1','2','f3')
>> get_path(myjson,'{f1,2,f3}')
>
> I would change these to mention the return types:
>
> get_json(myjson,0)
> get_json(myjson,'f1')
> get_json(myjson,'f1','2','f3')
> get_path_json(myjson,'{f1,2,f3}')
>
> And then the complementary text-returning versions:
>
> get_text(myjson,0)
> get_text(myjson,'f1')
> get_text(myjson,'f1','2','f3')
> get_path_text(myjson,'{f1,2,f3}')
>
> I do think that something like length() has pretty good semantics across data
> types, though. So to update the proposed names, taking in the discussion, I
> now propose:
>
> Existing Name Proposed Name
> -------------------------- -------------------
> json_array_length() length()
> json_each() each_json()
> json_each_as_text() each_text()
> json_get() get_json()
> json_get_as_text() get_text()
> json_get_path() get_path_json()
> json_get_path_as_text() get_path_text()
> json_object_keys() get_keys()
> json_populate_record() to_record()
> json_populate_recordset() to_records()
> json_unnest() get_values()
> json_agg() json_agg()
>
> I still prefer to_record() and to_records() to populate_record(). It just
> feels more like a cast to me. I dislike json_agg(), but assume we're stuck
> with it.
>
> But at this point, I’m happy to leave Andrew to it. The functionality is
> awesome.
Agreed: +1 to your thoughts here. But also +1 to the originals and +1
to Robert's point of view also. This feature is of huge strategic
importance to the project and we need to lock this down and commit it.
There is a huge difference between "i slightly prefer some different
names" and "the feature has issues".
So, i think the various positions are clear: this is one argument i'd
be happy to lose (or win).
merlin
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