Re: add function argument names to regex* functions.

On Thu, Jan 18, 2024 at 4:17 PM Peter Eisentraut <peter(at)eisentraut(dot)org> wrote:
>
> On 10.01.24 15:18, jian he wrote:
> > I put the changes into the new patch.
>
> Reading back through the discussion, I wasn't quite able to interpret
> the resolution regarding Oracle compatibility. From the patch, it looks
> like you chose not to adopt the parameter names from Oracle. Was that
> your intention?
>

per committee message:
https://git.postgresql.org/cgit/postgresql.git/commit/?id=6424337073589476303b10f6d7cc74f501b8d9d7
Even if the names are all the same, our function is still not the same
as oracle.

There is a documentation bug.
In [0], Table 9.25. Regular Expression Functions Equivalencies
regexp_replace function definition: regexp_replace(string, pattern, replacement)

In one of the <tip> section below, regexp_replace explains as
<<<<<
The regexp_replace function provides substitution of new text for
substrings that match POSIX regular expression patterns. It has the
syntax regexp_replace(source, pattern, replacement [, start [, N ]] [,
flags ]). (Notice that N cannot be specified unless start is, but
flags can be given in any case.)
<<<<<
So I changed the first argument of regexp_replace to "string". So
accordingly, the doc needs to change also, which I did.

another regex* function argument changes: from "N" to "occurences", example:
+ If <replaceable>occurrence</replaceable> is specified
+ then the <replaceable>occurrence</replaceable>'th match of the pattern
+ is located,

but [2] says
Speaking of the "occurrence'th
occurrence" is just silly, not to mention long and easy to misspell."

summary:
adding function-named notation is my intention.
To make regex.* functions named-notation works, we need to add
proargnames to src/include/catalog/pg_proc.dat.
add proargnames also require changing the doc.
naming proargnames is a matter of taste now, So I only change 'N' to
'occurrence'.

[0] https://www.postgresql.org/docs/current/functions-matching.html
[1] https://www.postgresql.org/message-id/flat/fc160ee0-c843-b024-29bb-97b5da61971f%40darold.net