Linux and the 'clssic' computing world
Van Snyder
van.snyder at sbcglobal.net
Tue Sep 28 17:34:15 CDT 2021
On Tue, 2021-09-28 at 17:03 -0500, Jay Jaeger via cctalk wrote:
> > On 2021-09-28 11:43 a.m., Vincent Long standing via cctalk wrote:
> >
> > > The C standards are more liberal, and continue to require char
> > > types
> > > to be 8 or more bits.
> > Was PL/I the only language that would let you select data size for
> > variables? Of course the fine print would not let you have more
> > than 16
> > decimal digits, or 32 bit binary. You would think by now that a
> > language
> > could handle any length data.
> >
>
> Hardly.
>
> FORTRAN: INTEGER*4 INTEGER*8 (and sometimes INTEGER*2 - e.g. Sun
> FORTRAN-77) was common, though never adopted as a standard. Also
> REAL
> vs. DOUBLE.
Fortran 90 introduced "kind type parameters" for all types. For REAL,
one can use SELECTED_REAL_KIND to ask for a specific number of decimal
digits. The standard does not require any minimum number be required.
Both "default real" and double precision are required. Many processors
provide quad precision. For INTEGER, one can use SELECTED_INT_KIND.
Processors are required to provide at least one kind with at least 18
decimal digits. There is no specification which other sizes are
required.
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