Re: proposal: plpgsql - Assert statement - Mailing list pgsql-hackers

From Robert Haas
Subject Re: proposal: plpgsql - Assert statement
Date
Msg-id CA+TgmoYCh+b85-yM943VkUdGuXnr-GVHtGeeWn1bCJN8wFKBfw@mail.gmail.com
Whole thread Raw
In response to Re: proposal: plpgsql - Assert statement  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Wed, Nov 19, 2014 at 12:01 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Wed, Nov 19, 2014 at 11:13 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> FWIW, I would vote against it also.  I do not find this to be a natural
>>> extension of RAISE; it adds all sorts of semantic issues.  (In particular,
>>> what is the evaluation order of the WHEN versus the other subexpressions
>>> of the RAISE?)
>
>> What I liked about this syntax was that we could eventually have:
>> RAISE ASSERT WHEN stuff;
>> ...and if assertions are disabled, we can skip evaluating the
>> condition.  If you just write an IF .. THEN block you can't do that.
>
> Well, if that's what you want, let's just invent
>
> ASSERT condition
>
> and not tangle RAISE into it.  The analogy to EXIT WHEN is a lot
> cleaner in this form: no order-of-evaluation issues, no questions
> of whether a sub-clause results in totally changing the meaning
> of the command.  And if your argument is partially based on
> how much you have to type, doesn't this way dominate all others?

That doesn't bother me any.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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