I entirely agree with David. Co-arrays may be important for some users on some architectures but by
no means all of either. They are too "flavour of the month" and as yet unproven as even a better way
of doing explicit parallelism let alone best on the architectures that do suit them. They must be
optional.
--
Lawrie Schonfelder
Wirral, UK
> -----Original Message-----
> From: Fortran 90 List [mailto:[log in to unmask]]On Behalf
> Of David Muxworthy
> Sent: 24 August 2008 16:52
> To: [log in to unmask]
> Subject: Re: j3 responses to public comments
>
>
> On Sat, 23 Aug 2008 02:31:50 -0700, Van Snyder <[log in to unmask]> wrote:
>
> > The view of the US delegation to the ISO
> >working group is that parallelism will become so important so soon that
> >CoArrays should not be delayed, and should not be optional (optional
> >stuff has never been successful in Fortran).
>
> The two optional parts of the current standard are unsuccessful not because
> they are optional, but because there is no demand for them.
>
> Part 2 (varying length character strings) was created principally to help
> buy votes for Fortran 90. It also served as a feasibility proof for
> modules. Serious usage was not the prime concern.
>
> Proposals for conditional compilation arose partly from an informal request
> from HPFF in the early 1990s and partly as it was realised that cpp and fpp
> were being widely used but were not considered sufficiently Fortran-like.
> Conditional compilation was rejected as a requirement for inclusion in the
> base language but was accepted in 1995, with less than wholehearted
> enthusiasm, to be an optional part 3. The standard was published in 1999,
> by which time anyone who wanted this facility was almost certainly using
> other tools.
>
> The previous option in Fortran was subset Fortran 77 which never really took
> off, probably because it was overtaken by increasing machine size and
> improved compiling techniques.
>
> Optional parts are however fully part of the standard and are there to be
> used by those vendors and users who want them. There is no logic in saying
> that because coarrays are important, they must be in the base language.
> Important for whom? If there is demand they will be used. There are a
> number of reasons why they should be an option. A primary one is that, when
> it is realised that the coarray model is not the best one to pursue, the
> Fortran base language will not be lumbered with lots of redundant syntax and
> complexity.
>
> David Muxworthy
>
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