Mark Dilger <pgsql@markdilger.com> writes:
> Tom Lane wrote:
>> No it isn't. The plpgsql scanner treats := and = as *the same token*.
>> They can be interchanged freely. This has nothing to do with the case
>> of modifying a loop variable in particular.
>
> I disagree. If the scanner treated them the same, then
>
> if i := 1 then ...
>
> would work, but it doesn't. The := is rejected in a conditional. Try the
> following code if you don't believe me:
That's because (AIUI) all expressions to be evaluated are handed off
to the SQL parser (why re-implement all that logic and have subtle and
annoying differences?) plpgsql only handles the statements, loops, etc.
So it doesn't care about the difference but SQL does...
Not that I claim that makes sense. :)
-Doug