Re: proposal: FOREACH-IN-ARRAY (probably for 9.2?) - Mailing list pgsql-hackers

From Merlin Moncure
Subject Re: proposal: FOREACH-IN-ARRAY (probably for 9.2?)
Date
Msg-id AANLkTimYbcYA7=FLDu4zwmhTRVGM+oo_=nHqo95=FQ+X@mail.gmail.com
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In response to Re: proposal: FOREACH-IN-ARRAY (probably for 9.2?)  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: proposal: FOREACH-IN-ARRAY (probably for 9.2?)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Fri, Dec 17, 2010 at 10:47 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Pavel Stehule <pavel.stehule@gmail.com> writes:
>> I am resending a redesigned proposal about special plpgsql statement
>> that support iteration over an array.
>
> OK ...
>
>> == Iteration over multidimensional arrays ==
>> Its designed to reduce one dimension from source array. It can remove
>> a slicing and simplify code:
>
> This seems like a really bad, confusing idea.  I think it should throw
> a type-mismatch error in this case.  If there is any use-case for such a
> thing, which I'm quite unconvinced of, it ought to use a separate syntax
> rather than overloading the element-by-element syntax.

I don't agree at all -- iterating arrays by slice is a frequently
requested feature (you can kinda sorta do it by slice notation, but
arr[n] giving null is a -general FAQ.  This is how people think arrays
should work.  I suppose that having this functionality reserved in a
tiny corner of plpgsql is not so good, but I think foreach... would
become the preferred way to iterate arrays always.

merlin


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