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Re: Expression evaluation [was Re: I vote NO ...]

Nick Maclaren wrote:

In particular, I regard any hint that such a standard includes a
requirement for established languages to make unacceptable changes
as almost certain to kill acceptance.

But, to make a more positive contribution, here is another approach:

   Expressions are required to return an interval that must contain
   all of the possible values resulting from a mathematically perfect
   evaluation of all possible values in the input intervals.

Both the performance and tightness of the result would be quality of
implementation issues.


Amen.

This is particularly true when considering the topic of property tracking
with decorations. But unfortunately, most of that lengthy discussion has
taken place offline over the past 5 months, so I suspect few people
listening will know why I mention that.

Nate




And, yes, a compiler WOULD be allowed to replace
an expression by a numerically better equivalent.  Most compilers would
then have flags, choosing the balance.

That was also my preference for IEEE 754 support, incidentally, but it's
trickier to specify for that.


Regards,
Nick.