Re: "The Best Programming Language for the End of the World"

On 8/04/2025 9:43 pm, Hans Bezemer wrote:

On 07-04-2025 13:05, dxf wrote:
As a matter of fact, the whole issue can be solved by one single very simple addition to the standard. All my FP systems hold this very definition for SET-PRECISION:
 
\ 34: Reimplemented PRECISION and SET-PRECISION.
maxdigits VALUE PRECISION
: SET-PRECISION ( n -- )         maxdigits MIN TO PRECISION ;
 
Since the FLOAT wordset is always in decimal (12.4.1.2 Ambiguous conditions - BASE is not decimal (12.6.1.2143 REPRESENT, 12.6.2.1427 F., 12.6.2.1513 FE., 12.6.2.1613 FS.) it is trivial to calculate the number of significant digits.
 
The definition given here ( --- CONSTANT MAXDIGITS) ensures that the value issued to SET-PRECISION is always sane.
 
Of course, if one does not have access to some carnal knowledge concerning the mantissa, one does have a problem concerning porting and maintenance.

It's not SET-PRECISION (presumably the implementer has made that sane)
but rather variability when values are sane e.g.

6 set-precision  ok
1e-4 f.  0.000100000  ok
>
6 set-precision  ok
1e-4 f. 0.0001  ok

While both of those are numerically correct, they're plainly different i.e.
11 characters vs. 6 characters.  As an app writer I'd like some uniformity
here as I might want to output several columns of numbers on a screen.  To
do that I need to know how wide to make those columns.

I can't believe other langs have this issue as it would be hard to write
portable apps?