(j3.2006) (SC22WG5.4773) [ukfortran] [Letter ballot 3 on Fortran 2008interpretations]

[Van Snyder]

On Tue, 2012-09-18 at 13:17 +0900, Malcolm Cohen wrote:
> 
> Bill wrote:
> >However, this argument of
> >"better answers", particularly in "the vast majority of cases", does not
> >make sense to me.
> 
> I am not arguing that the standard needs to change to permit better answers, 
> just that it should not change to forbid them.

Neither answer to the interpretation involves edits.  The
interpretation, as it stands, forbids better answers.

> The naive application of the 
> thinking behind this interp would prohibit raising the precision of any 
> operation - and this would indeed lead to Worse Answers in the vast majority of 
> cases.  In general, evaluating a whole expression in the maximum precision 
> available and only rounding it to a smaller storage format on assignment 
> produces more accurate results than rounding to the smaller format after each 
> operation; this is a plain fact. 

This is nonsense.  There is no counterpart to 13.7.1p2 anywhere in
Clause 7, and, as far as I know, nobody is proposing that there ought to
be one.  There is a trivial workaround for wanting REAL(X,K) to be NOP:
X.  There ought to be a trivial workaround for wanting REAL(X,K) to be
REAL(X,K): REAL(X,K).