Horton

Re: More new SQL/JSON item methods

Chapman Flack <chap@anastigmatix.net>

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From: Chapman Flack <chap@anastigmatix.net>
To: Vik Fearing <vik@postgresfriends.org>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Jeevan Chalke <jeevan.chalke@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-09-01T01:41:40Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Rationalize and improve error messages for some jsonpath items

  2. Clean up a bug in sql/json items commit 66ea94e8e6

  3. Implement various jsonpath methods

  4. Reorganise jsonpath operators and methods

  5. Add numeric_int8_opt_error() to optionally suppress errors

On 2023-08-31 20:50, Vik Fearing wrote:
>   — An SQL/JSON item is defined recursively as any of the following:
> ...
>     • An SQL/JSON array, defined as an ordered list of zero or more
>       SQL/JSON items, called the SQL/JSON elements of the SQL/JSON
>       array.
> ...
>   — An SQL/JSON sequence is an ordered list of zero or more SQL/JSON
>     items.

As I was thinking, because "an ordered list of zero or more SQL/JSON
items" is also exactly what an SQL/JSON array is, it seems at least
possible to implement things that are specified to return "SQL/JSON
sequence" by having them return an SQL/JSON array (the kind of thing
that isn't possible for XML(SEQUENCE), because there isn't any other
XML construct that can subsume it).

Still, it seems noteworthy that both terms are used in the spec, rather
than saying the function in question should return a JSON array. Makes
me wonder if there are some other details that make the two distinct.

Regards,
-Chap