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

On 11/04/2025 11:50 pm, Hans Bezemer wrote:

On 11-04-2025 05:52, dxf wrote:

With REPRESENT we're dealing with full-precision numbers being displayed
in lesser precision.  Would 'significant digits plus one' even apply?

I did more digging into the subject that I probably should have done - but I think so. IMHO there is no consensus (either in the standard nor elsewhere) what "significant digits" are. However I found that:
 
1. The significant seems to be the main source of "significant digits";
 
2. Either large exponents (and digits to the right of integer upto the decimal point) - or small exponents (and digits to the left upto the decimal point) are often referred to as "placeholders" AKA - not part of the "significant digits";
 
3. Leading zeroes (before the decimal point, but preceding the significant digits) or trailing zeroes (after the decimal point, but following the significant digits) are not placeholders. Note that some "trailing zeroes" can be significant digits;
 
4. The rightmost digit of the "significant digits", even when incorrect - is part of the significant digits.
 
And yeah, then there are things like rounding, "trapped zeroes", exact numbers - Oof!
 
But I think it would help if a definition of significant digits would be added to the standard. Now everybody is guessing what it means..

Perhaps I'm missing something but looking at:

https://en.wikipedia.org/wiki/Significant_figures

subsection "Rounding to significant figures" I'm not seeing anything unexpected
or ambiguous.