Re: Surprise in array concatenation

[Dave Thompson <david.thompson1@worldnet.att.net>]

On 05 Sep 2005 19:46:13 -0400, Robert A Duff
<bobduff@shell01.TheWorld.com> wrote:

> Kilgallen@SpamCop.net (Larry Kilgallen) writes:
> 
> > In article <wcck6hvnpsm.fsf@shell01.TheWorld.com>, Robert A Duff <bobduff@shell01.TheWorld.com> writes:
<snip>
> > > Heh?  The lower (and upper!) bound of all array types in Pascal is
> > > fixed.  And it has to be fixed at a static value.  Every array object of
> > > a given type has the same fixed bounds.
> > > 
> > > (Well, some version of Pascal added conformant arrays, which relaxed
> > > this requirement for formal parameters.)
> > 
> > That is true, in the same sense that some versions of Ada added
> > modular types -- they were added to the standard.
> 
> Right.  I was being vague because I couldn't remember whether conformant
> arrays were added in the first ISO Pascal standard, or the Extended
> Pascal version.  I also can't remember the status of Extended Pascal
> (was it ever officially blessed by ISO?).  Do you know?
> 
They were added as an option, "Level 1", in the first standard (7185),
and in fact are called out in the introductory section as one of only
two "major" changes made during standardization.  The Extended Pascal
standard (10206), which I've found lying about but not actually used,
and is on sale which I believe means approved at ANSI and ISO, adds
(purportedly?) more powerful "schemas" which I have not taken the time
to understand but apparently "subsume" conformant arrays.

> Conformant arrays were certainly not part of the original Pascal as
> documented in Jensen and Wirth's book, "Pascal User Manual and Report".
> And conformant arrays are only for parameters -- not normal variables,
> record components, heap objects, etc.  Correct?
> 
AIUI correct.

- David.Thompson1 at worldnet.att.net