Re: proposal: FOREACH-IN-ARRAY (probably for 9.2?)

From: Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
To: Andrew Dunstan <andrew(at)dunslane(dot)net>
Cc: Itagaki Takahiro <itagaki(dot)takahiro(at)gmail(dot)com>, Merlin Moncure <mmoncure(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: proposal: FOREACH-IN-ARRAY (probably for 9.2?)
Date: 2010-12-17 17:35:28
Message-ID: AANLkTikLAUTme_xbuJE=DUp0VMap2z=OQrHu7Np8qs1_@mail.gmail.com
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2010/12/17 Andrew Dunstan <andrew(at)dunslane(dot)net>:
>
>
> On 12/17/2010 12:15 PM, Pavel Stehule wrote:
>>
>> 2010/12/17 Itagaki Takahiro<itagaki(dot)takahiro(at)gmail(dot)com>:
>>>
>>> It should be not a main subject, but I remember there was a discussion
>>> that "IN ARRAY array-expression" looks redundant for a literal array:
>>>
>>>  IN ARRAY ARRAY[1, 3, 5]
>>>
>>> Are there any improvement for the issue?
>>
>> yes. It know it. The reason for this is bigger space for possible
>> future features related to FOREACH loop.
>>
>
> So what you're saying is we need to allow ugliness now so we can have more
> ugliness in future? I don't find that a convincing argument. I share the
> dislike for this syntax.

can be strange from me, but it is. If we close a back door now, then
we have not a space after ten years. There can be possible loops over
records, maybe over other iterable data. With this design is important
one think. A keyword after K_IN must not be a reserved keyword.

I am expecting, so typical use case doesn't be a iteration over
constant array, but over variable

so mostly often you have to write

FOREACH var IN ARRAY second_var
LOOP
...
END LOOP

Regards

Pavel

>
> cheers
>
> andrew
>

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