Re: forall and do loop

glen herrmannsfeldt <gah@xxxxxxxxxxxxxxxx> wrote:

If I designed FORALL I would have allowed intermixing of evaluation
and assignment in any order, and left it to the programmer to be sure
that would work.

That amounts to restricting it to the cases trivial enough that most
compilers probably don't generate temporaries today anyway. So you'd get
the same effect as today on that subset of cases, and you'd just say
that the other cases were illegal. Anyway, that's how I'd translate the
above.

I'm interpreting "left it to the programmer to be sure that would work"
as requiring the programmer to code in such a way that the same results
would be obtained for any order of evaluation and assignment. Otherwise,
I have no idea what you would mean (though that seems to happen a bit,
so it might be the case here as well).

If I understand things correctly, that's at least close to the proposed
specification of DO CONCURRENT, but the DO allows things in addition to
just assignment, so it adds some capability to make up for the ones that
it drops.

I would hope you don't mean it in the sense of "here's a syntax, but the
standard doesn't say anything about what it means; it is up to the
programmer to know what a particular compiler means by it." Admitedly
there is precedence in that that's not too far off from how the standard
specifies VOLATILE. :-(

--
Richard Maine | Good judgement comes from experience;
email: last name at domain . net | experience comes from bad judgement.
domain: summertriangle | -- Mark Twain
.