Larry Wall wrote: > So it might be better as a (very tight?) operator, regardless of > the spelling: > > $x ~~ $y within $epsilon
I like this: it's readable and intuitive. As well, it leaves ± available for use in its mathematical sense. > For what it's worth, ± does happen to be in Latin-1, and therefore > officially fair game for Standard Perl. By the way, the mathematical > definition can be derived from the engineering definition with > > if $x == ($x ± $epsilon).minmax.any > > The problem with defining it the other direction is that junctions > tend to lose ordering information of their eigenstates, and we can't > just flip mins and maxes when we feel like it, or degenerate null > ranges get broken. OTOH, there aren't going to be very many cases where you're going to want to derive either from the other. You're more likely to derive both from the same base stock: $y ± 5 # same as ($y - 5) | ($y + 5) $y within 5 # same as ($y - 5) .. ($y + 5) -- Jonathan "Dataweaver" Lang
