Robin wrote:
>> Date: Sat, 06 Mar 2004 12:05:45 +0900
>> From: Yasuki Arasaki <[log in to unmask]>
>
>> The one thing I don't like about Fortran is [...] the fact that default
>> real seems to be converging on four bytes. In F77 days I used only
>> DOUBLE PRECISION with all real literals with a D exponent. That was
>> ugly then, but in F90 I explicitly specify kind parameters for all
>> real literals (not really all, I use "2" instead of "2.0_rk").
>> Fortran is supposed to be for number crunching, but the most
>> convenient default real can not be trusted.
>
> In what way?
> Default real is default real.
> 1. 2. 3. 4. 5. etc are default reals.
> They are always default real.
> They never change from default real.
But, default real is what the implementation says it is. There is
no reason that a compiler directive or command-line switch
couldn't be provided that allows the user to select what precision
default real is compiled to. Some compilers already do so. If
such a control were part of the standard, it would be a much
better solution to a common problem (changing the KIND used
by the whole program) than having to rewrite every literal in
the whole program so that it includes KIND specifiers.
Literals without KIND are more legible for a start.
--
J. Giles
|