Re: builtin functions, parameter names and psql's \df

Hi,

on a regular basis I remember a builtin function's name, or can figure it out
using \df etc, but can't remember the argument order. A typical example is
regexp_*, where I never remember whether the pattern or the input string comes
first.

Unfortunatly \df does not really help with that:

=# \df regexp_split_to_table
┌────────────┬───────────────────────┬──────────────────┬─────────────────────┬──────┐
│   Schema   │         Name          │ Result data type │ Argument data types │ Type │
├────────────┼───────────────────────┼──────────────────┼─────────────────────┼──────┤
│ pg_catalog │ regexp_split_to_table │ SETOF text       │ text, text          │ func │
│ pg_catalog │ regexp_split_to_table │ SETOF text       │ text, text, text    │ func │
└────────────┴───────────────────────┴──────────────────┴─────────────────────┴──────┘

If the parameters were named however, it'd be clear:

=# CREATE OR REPLACE FUNCTION pg_catalog.regexp_split_to_table(string text, pattern text)
 RETURNS SETOF text
 LANGUAGE internal
 IMMUTABLE PARALLEL SAFE STRICT
AS $function$regexp_split_to_table_no_flags$function$

=# \df regexp_split_to_table
┌────────────┬───────────────────────┬──────────────────┬──────────────────────────┬──────┐
│   Schema   │         Name          │ Result data type │   Argument data types    │ Type │
├────────────┼───────────────────────┼──────────────────┼──────────────────────────┼──────┤
│ pg_catalog │ regexp_split_to_table │ SETOF text       │ string text, pattern text │ func │
│ pg_catalog │ regexp_split_to_table │ SETOF text       │ text, text, text         │ func │
└────────────┴───────────────────────┴──────────────────┴──────────────────────────┴──────┘

(I intentionally left the three parameter version unchanged, to show the difference)


In the docs we already name the parameters using SQL like syntax, see [1]. How
about we actually do so for at least the more common / complicated functions?