Re: PSQL commands: \quit_if, \quit_unless

On 11/30/2016 03:47 AM, Fabien COELHO wrote:
>
> Hello Andrew,
>
>>> I cannot remember a language with elseif* variants, and I find them 
>>> quite ugly, so from an aethetical point of view I would prefer to 
>>> avoid that... On the other hand having an "else if" capability makes 
>>> sense (eg do something slightly different for various versions of 
>>> pg), so that would suggest to stick to a simpler "if" without 
>>> variants, if possible.
>>
>> FTR I *strongly* disagree with this. (And if you can't remember a 
>> language that comes with them then you need to get out more. The 
>> Bourne shell, where it's spelled "elif", and Ada are two obvious 
>> examples.)
>
> There may be a misunderstanding somewhere.
>
> I'm rather in favor of having "elif/elsif/elseif/..." constructs, 
> especially if they can be useful in realistic examples, which is not 
> clear yet for psql scripts.
>
> I'm arguing against "if/elif" *variants* in the sense of various 
> conditional semantics: e.g. in cpp you have several "if"s (ifdef 
> ifndef if), but you do not have all the corresponding "elif"s (elifdef 
> elifndef...), there is only one "elif". In cpp "ifdef"/"ifndef" were 
> obsoleted by "if" with minimal expression support (#if 
> !defined(HAS_SOMETHING) ...) and only this "if" has its "elif".
>

Oh, I see. Sorry for the misunderstanding.

I agree about generally sticking with one pattern, but I wouldn't want 
to exclude shorthand pieces like
    \quit_if cond

which could be more convenient than
    \if cond        \quit    \endif

c.f. perl's "foo if bar;" as shorthand for "if (bar) { foo; }"

Still, that might be a refinement to add later on.

cheers

andrew