Subject: Re: jsonpath
To: Alexander Korotkov <a.korotkov@postgrespro.ru>,
 Nikita Glukhov <n.gluhov@postgrespro.ru>
Cc: Michael Paquier <michael@paquier.xyz>,
 Stas Kelvich <s.kelvich@postgrespro.ru>,
 PostgreSQL-development <pgsql-hackers@postgresql.org>,
 Thomas Munro <thomas.munro@enterprisedb.com>,
 David Steele <david@pgmasters.net>, Tom Lane <tgl@sss.pgh.pa.us>,
 Andrew Dunstan <andrew.dunstan@2ndquadrant.com>,
 Robert Haas <robertmhaas@gmail.com>, Oleg Bartunov <obartunov@gmail.com>,
 Pavel Stehule <pavel.stehule@gmail.com>
References: 
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 <CAEepm=0jJ4fkEWLHc2Rqt5F4Und6qd+60pxFQmCnbf0nYYjrcg@mail.gmail.com>
 <3bc15ece-5219-e4ca-0b5c-fcd2b276aa26@postgrespro.ru>
 <4e2aaa88-3bbf-6af3-8dad-d5687fbec89f@postgrespro.ru>
 <42272F2B-16D1-43D6-B22F-273AE1DA6D6B@postgrespro.ru>
 <715c1c44-9bb9-6b9f-7c59-61b66578f107@postgrespro.ru>
 <20181002023317.GI11712@paquier.xyz>
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 <9a175c2d-b0a9-475f-078b-febc185282ff@postgrespro.ru>
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 <64e3108c-888f-092e-30a2-58dea157707e@postgrespro.ru>
 <43e52ed7-9c21-db2c-693a-9245f9e8ce2a@2ndquadrant.com>
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 <CAPpHfdvVyXsD1gSwVB7A2C07Mx_6XZOOpEBqO_Le11mYJyq8YQ@mail.gmail.com>
From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Message-ID: <787430e1-da7d-6180-6ce6-32bd4b0c1ae0@2ndquadrant.com>
Date: Sat, 5 Jan 2019 15:21:03 +0100
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On 1/5/19 1:11 AM, Alexander Korotkov wrote:
> On Tue, Dec 4, 2018 at 2:23 AM Nikita Glukhov <n.gluhov@postgrespro.ru> wrote:
>> 2) We define both DCH_FF# and DCH_ff#, but we never ever use the
>> lower-case version. Heck, it's not mentioned even in DCH_keywords, which
>> does this:
>>
>>   ...
>>   {"FF1", 3, DCH_FF1, false, FROM_CHAR_DATE_NONE},  /* F */
>>   ...
>>   {"ff1", 3, DCH_FF1, false, FROM_CHAR_DATE_NONE},  /* F */
>>   ...
>>
>> Compare that to DCH_DAY, DCH_Day and DCH_day, mapped to "DAY", "Day" and
>> "day".
>>
>> Yes, "ff#" are mapped to DCH_FF# like "mi" is mapped DCH_MI.
>>
>> "Day", "day" are not mapped to DCH_DAY because they determine letter case in the
>> output, but "ff1" and "FF#" output contains only digits.
> 
> Right, DCH_poz is also offset in DCH_keywords array.  So, if array has
> an entry for "ff1" then enum should have a DCH_ff1 member in the same
> position.
> 

I guess my question is why we define DCH_ff# at all, when it's not
mapped in DCH_keywords? ISTM we could simply leave them out of all the
arrays, no? Of course, this is not specific to this patch, as it applies
to pre-existing items (like DCH_mi).

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services