Re: doc: improve PG 12 to_timestamp()/to_date() wording

Hi!

I'd like to add couple of comments from my side.

On Tue, Apr 30, 2019 at 9:36 PM Justin Pryzby <pryzby@telsasoft.com> wrote:

I saw this commit;
commit ad23adc5a169b114f9ff325932cbf2ce1c5e69c1
|Author: Bruce Momjian <bruce@momjian.us>
|Date: Tue Apr 30 14:06:57 2019 -0400
|
| doc: improve PG 12 to_timestamp()/to_date() wording

which cleans up language added at cf984672.

Can I suggest this additional change, which is updated and extracted from my
larger set of documentation fixes.

Justin

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 96fafdd..b420585 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -6400,20 +6400,20 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
</para>
<para>
If <literal>FX</literal> is specified, a separator in the template string
-       matches exactly one character in input string.  Notice we don't insist the
-       input string character be the same as the template string separator.
+       matches exactly one character in the input string.  But note that the
+       input string character is not required to be the same as the separator from the template string.

Looks good for me.

For example, <literal>to_timestamp('2000/JUN', 'FXYYYY MON')</literal>
works, but <literal>to_timestamp('2000/JUN', 'FXYYYY&nbsp;&nbsp;MON')</literal>
-       returns an error because the second template string space is consumed
-       by the letter <literal>J</literal> in the input string.
+       returns an error because the second space in the template string consumes
+       the letter <literal>M</literal> from the input string.
</para>
</listitem>

Why <literal>M</literal>? There is no letter "M" is input string.
The issue here is that we already consumed "J" from "JUN" and trying
to match "UN" to "MON". So, I think we should live
<literal>J</literal> here. The rest of this change looks good.

<listitem>
<para>
A <literal>TZH</literal> template pattern can match a signed number.
-       Without the <literal>FX</literal> option, it can lead to ambiguity in
-       interpretation of the minus sign, which can also be interpreted as a separator.
+       Without the <literal>FX</literal> option, minus signs may be ambiguous,
+       and could be interpreted as a separator.
This ambiguity is resolved as follows:  If the number of separators before
<literal>TZH</literal> in the template string is less than the number of
separators before the minus sign in the input string, the minus sign

Looks good for me.

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

On Tue, Apr 30, 2019 at 09:48:14PM +0300, Alexander Korotkov wrote:

I'd like to add couple of comments from my side.

-       returns an error because the second template string space is consumed
-       by the letter <literal>J</literal> in the input string.
+       returns an error because the second space in the template string consumes
+       the letter <literal>M</literal> from the input string.

Why <literal>M</literal>? There is no letter "M" is input string.
The issue here is that we already consumed "J" from "JUN" and trying
to match "UN" to "MON". So, I think we should live
<literal>J</literal> here. The rest of this change looks good.

Seems like I confused myself while resolving rebase conflict.

Thanks for checking.

Justin

On Tue, Apr 30, 2019 at 07:14:04PM -0500, Justin Pryzby wrote:

On Tue, Apr 30, 2019 at 09:48:14PM +0300, Alexander Korotkov wrote:

I'd like to add couple of comments from my side.

-       returns an error because the second template string space is consumed
-       by the letter <literal>J</literal> in the input string.
+       returns an error because the second space in the template string consumes
+       the letter <literal>M</literal> from the input string.

Why <literal>M</literal>? There is no letter "M" is input string.
The issue here is that we already consumed "J" from "JUN" and trying
to match "UN" to "MON". So, I think we should live
<literal>J</literal> here. The rest of this change looks good.

Seems like I confused myself while resolving rebase conflict.

Thanks for checking.

Find attached updated patch, which seems to still be needed.

This was subsumed and now extracted from a larger patch, from which Michael at
one point applied a few hunks.
I have some minor updates based on review from Andres, but there didn't seem to
be much interest so I haven't pursued it.
/messages/by-id/20190520182001.GA25675@telsasoft.com

Justin

On Sat, Jul 6, 2019 at 03:24:25PM -0500, Justin Pryzby wrote:

On Tue, Apr 30, 2019 at 07:14:04PM -0500, Justin Pryzby wrote:

On Tue, Apr 30, 2019 at 09:48:14PM +0300, Alexander Korotkov wrote:

I'd like to add couple of comments from my side.

-       returns an error because the second template string space is consumed
-       by the letter <literal>J</literal> in the input string.
+       returns an error because the second space in the template string consumes
+       the letter <literal>M</literal> from the input string.

Why <literal>M</literal>? There is no letter "M" is input string.
The issue here is that we already consumed "J" from "JUN" and trying
to match "UN" to "MON". So, I think we should live
<literal>J</literal> here. The rest of this change looks good.

Seems like I confused myself while resolving rebase conflict.

Thanks for checking.

Find attached updated patch, which seems to still be needed.

This was subsumed and now extracted from a larger patch, from which Michael at
one point applied a few hunks.
I have some minor updates based on review from Andres, but there didn't seem to
be much interest so I haven't pursued it.
/messages/by-id/20190520182001.GA25675@telsasoft.com

Patch applied back through PG 12. Thanks.

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +