On 11.02.2019, at 00:54, Nicolas Cellier nicolas.cellier.aka.nice@gmail.com wrote:
Le dim. 10 févr. 2019 à 20:16, Eliot Miranda eliot.miranda@gmail.com a écrit :
_,,,^..^,,,_ (phone)
On Feb 10, 2019, at 6:27 AM, Nicolas Cellier nicolas.cellier.aka.nice@gmail.com wrote:
Hi, does anyone really need a fuzzy Interval indexOf:startingAt: ? Right now, we have this:
((0.1 to: 0.9 by: 0.1) indexOf: 0.3) = 3. ((0.1 to: 0.9 by: 0.1) includes: 0.3) = true.While this can sound nice, I don't think it is. No other collection behaves like that.
((0.1 to: 0.9 by: 0.1) asArray includes: 0.3) = false. ((0.1 to: 0.9 by: 0.1) asSet includes: 0.3) = false.What if instead we added a range numeric type? Then we could write something like
((0.1 to: 0.9 by: 0.1) asArray includes: (0.3 plusOrMinus: 0.001)) = true.
You can even use a nice binary operator 0.3 +/- 0.001 :)
or even ± for that matter :)
NumericRange would be instantiated via plusOrMinus: & from:to:, and implement interval arithmetic and interval comparison. So = would be
= aMagnitude ^aMagnitude between: start and stop
and NumericRange would itself use its midpoint for comparisons against magnitudes. It would presumably not be a magnitude itself though, so that two NumericRanges would be equal only if they represented the same range, not had the same midpoint.
All these solutions make = not transitive... a = b && (b = c) ==> (a = c)
So if we want interval arithmetic we'd rather use another set of selectors for achieving this fuzzyfication...
Even Interval itself does not behave consitently:
((0.1 to: 0.9 by: 0.1) lastIndexOf: 0.3) = 0. ((0.1 to: 0.9 by: 0.1) occurrencesOf: 0.3) = 0. ((0.1 to: 0.9 by: 0.1) copyWithout: 0.3) = #(0.1 0.2 0.30000000000000004 0.4 0.5 0.6 0.7000000000000001 0.8 0.9).We have ScaledDecimal and Fraction which are less surprising, so IMO we should better use them when we really want to play with equality rather than trying to cheat with Float equality.