As I remember PL/1 from the 1980s (and very definitely pre-LE) the rules
for implicit conversions were well-defined, but needed care. Simply adding
parentheses would allow me to control the use of integer operations.
I'll be watching for more recent (relevant) exerience :-)
Rupert
On Sun., Sep. 6, 2020, 14:07 Paul Gilmartin, <
0000000433f07816-dmarc-requ...@listserv.ua.edu> wrote:
> On Sun, 6 Sep 2020 17:25:45 +1000, Robin Vowels wrote:
> >>>
> >> Beware! Than might left-associate as:
> >> volume = ( 4/3 ) * 3.14159 * radius**3
> >> ... and the quotient of integers, 4/3, is 1.
> >
> >No it's not. 4/3 yields 1.33333333333333.. to 15 digits in PL/I.
> >You're thinking of FORTRAN.
> >
> And C:
> 662 $ cat typetest.c
> #include <stdio.h>
> int main() {
> printf( "%10.6f\n", 4/3 * 3.14159 );
> printf( "%10.6f\n", 4.0/3 * 3.14159 ); }
> 663 $ gmake typetest && ./typetest
> cc typetest.c -o typetest
> 3.141590
> 4.188787
>
> It ought to depend on the types of the operands of the polymorphic
> operator, '/'. What are the default types of '4' and '3'? Does PL/I
> entirely lack an integer divide?
>
> The Language Ref. properly cautions that a constant declaration may
> be necessary to control the constant types.
>
> -- gil
>
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