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Thread: Suggested patch to plpgsql docs (7.4beta)

Suggested patch to plpgsql docs (7.4beta)

From
Richard Huxton
Date:
Addition of one paragraph to the end of section 39.7.3.4 "FOR (integer
variant)"

Note that this is basically a WHILE loop, so if the lower bound is larger than
the upper bound the loop never executes it's contents:
  FOR i IN 10..1 LOOP
    RAISE NOTICE ''I do not raise a notice %'',i;
  END LOOP;

I wasn't sure and had to check, so I assume others might find this useful too.
--
  Richard Huxton
  Archonet Ltd

Re: Suggested patch to plpgsql docs (7.4beta)

From
Peter Eisentraut
Date:
Richard Huxton writes:

> Addition of one paragraph to the end of section 39.7.3.4 "FOR (integer
> variant)"
>
> Note that this is basically a WHILE loop, so if the lower bound is larger than
> the upper bound the loop never executes it's contents:

I've added a note to this effect.  Thanks.

--
Peter Eisentraut   peter_e@gmx.net

Re: Suggested patch to plpgsql docs (7.4beta)

From
Bruce Momjian
Date:
Richard Huxton wrote:
> Addition of one paragraph to the end of section 39.7.3.4 "FOR (integer
> variant)"
>
> Note that this is basically a WHILE loop, so if the lower bound is larger than
> the upper bound the loop never executes it's contents:
>   FOR i IN 10..1 LOOP
>     RAISE NOTICE ''I do not raise a notice %'',i;
>   END LOOP;
>
> I wasn't sure and had to check, so I assume others might find this useful too.

I figured everyone would assume that.  I know of no language that will
execute a loop listed as 10 ... 1.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Re: Suggested patch to plpgsql docs (7.4beta)

From
Philip Yarra
Date:
On Thu, 4 Sep 2003 09:11 am, Bruce Momjian wrote:
> Richard Huxton wrote:
> > Addition of one paragraph to the end of section 39.7.3.4 "FOR (integer
> > variant)"
> >
> > Note that this is basically a WHILE loop, so if the lower bound is larger
> > than the upper bound the loop never executes it's contents:
> >   FOR i IN 10..1 LOOP
> >     RAISE NOTICE ''I do not raise a notice %'',i;
> >   END LOOP;
> >
> > I wasn't sure and had to check, so I assume others might find this useful
> > too.
>
> I figured everyone would assume that.  I know of no language that will
> execute a loop listed as 10 ... 1.

Basic on my first computer suppported it, though the syntax was

FOR $i in 10 TO 1 STEP -1
    PRINT $i
NEXT

I think it is worth stating explicitly. The apostrophe in "it's" is incorrect
though.

Regards, Philip Yarra.

Re: Suggested patch to plpgsql docs (7.4beta)

From
Tom Lane
Date:
Bruce Momjian <pgman@candle.pha.pa.us> writes:
> I figured everyone would assume that.  I know of no language that will
> execute a loop listed as 10 ... 1.

Fortran N for N < something-or-other.  I think Richard is betraying
his age ;-)

            regards, tom lane

Re: Suggested patch to plpgsql docs (7.4beta)

From
Richard Huxton
Date:
On Thursday 04 September 2003 04:32, Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > I figured everyone would assume that.  I know of no language that will
> > execute a loop listed as 10 ... 1.

I did assume that, then my paranoia kicked in suggesting it might be
constructing a list of values and stepping through them. The only reason I
could think it should behave like a while loop is that, well, all the others
do.

> Fortran N for N < something-or-other.  I think Richard is betraying
> his age ;-)

And how DARE you Tom - I clearly meant DotJavaWebSysNet or something trendy
like that and not some crufty version of BASIC from my 6502 days....;-)

--
  Richard Huxton
  Archonet Ltd