What Frank means is that Smalltalk Interval are countable (and most are finite).
However, the original usage of Interval was for Text editing, and an Interval from 5 to: 4 means that the cursor is before (after?) position 5. That's why Interval is a strange beast, not exactly polymorphic to an Array of Number. Those two views have introduced a number of unconsistencies in the library... Last thing, I don't recommend using Interval of Float, (1.5 to: 1.6 by: 0.01), rather use Integer or Fraction. You never know where the Float Interval really ends, it's progression is generally not constant, and to:do: used to behaved differently than do: Nicolas 2012/12/16 Igor Stasenko <[email protected]>: > On 16 December 2012 09:26, Frank Shearar <[email protected]> wrote: >> On 16 December 2012 01:06, Igor Stasenko <[email protected]> wrote: >>> On 15 December 2012 23:45, Chris Muller <[email protected]> wrote: >>>>> and i always hitting the wall with my head again and again.. because >>>>> there's no such protocol >>>>> and instead (after opening browser and looking at class, i figuring >>>>> that i should use #first/#last, but it is completely unintuitive to >>>>> me).. >>>> >>>> Me too, when I was using what I knew would only ever need to be, >>>> simply, an Interval. >>>> >>>> Later the complexity increased and it would be either a Interval or >>>> Array of numbers. It was a transparent / painless improvement. After >>>> gaining that appreciation, now I think of Intervals as just "efficient >>>> Arrays" and think naturally to use #first / #last. >>>> >>> >>> Well, my math background prevents me from thinking this way. >>> Since in math, intervals are defined on sets of numbers. >>> (like Real set).. you cannot treat it as array , simply because there >>> is an infinite number >>> of values inside any non-empty interval, and you cannot enumerate them. >> >> But it's a subset of the integers, not the reals! >> > what? > then how you explain this: > > (1.5 to: 1.6 by: 0.01) collect: [:i | i ] > >> frank >> >>> -- >>> Best regards, >>> Igor Stasenko. >>> >> > > > > -- > Best regards, > Igor Stasenko. >
