2014-05-18 19:19 GMT+02:00 Eliot Miranda <eliot.miranda@gmail.com>:
On Sun, May 18, 2014 at 10:04 AM, Sven Van Caekenberghe <sven@stfx.eu>wrote:
On 18 May 2014, at 18:50, Eliot Miranda <eliot.miranda@gmail.com> wrote:
On May 18, 2014, at 7:59 AM, kilon alios <kilon.alios@gmail.com> wrote:
yes I know, I was just wondering if that was normal behaviour because it looks quite confusing to me.
Personally I find it a natural way of expressing an empty interval. to: is syntactic sugar for to:by:, and so the default of 1 for the step (the by: arg) is expected.
I'm dissatisfied however that I can't write $A to: $Z, or 1 to: Infinity positive (or 1 to: Float inf, ugh).
It should be coupled to some lazy protocol (like Xtreams) otherwise any selector is going to loop infinitely.
Since there is Character>>#to: you can actually write $A to: $Z although
it returns an Array instead of a String, but that can be solved with
($a to: $z) as: String
or
String withAll: ($a to: $z)
Not that it answers a String in Squeak, because this seemed a more natural recipient than OrderedCollection to me (OrderedCollection it previously was).
Ugh, that's really bad. So if I want to construct an interval over the Unicode characters this hack instantiates a large string. The whole point about an Interval is to compute a set of values, not construct a collection. If I want to construct a collection I can.
I would add a subclass of Interval, say NonArithmeticInterval, that sent successor: step or predecessor: step so that e.g. Character>>successor: n ^Character value: self asInteger + n
Oh yes, that's coming directly from ASCII era when it did not matter. ... but then also to:do: and inlined variants will have to be hacked. Wouldn't the cost be a bit prohibitive?
Eliot (phone)
On Sun, May 18, 2014 at 4:49 PM, Eliot Miranda < eliot.miranda@gmail.com> wrote: Hi Kilon,
On May 18, 2014, at 6:32 AM, kilon alios <kilon.alios@gmail.com> wrote:
while I was recording my Interval video tutorial I observed that Interval does not behave as I would expect . Even though (1 to: 100) works as I expect, (1 to: -100) does not. In case of ( 1 to: -100) it created the interval object but it does not populate it with the numbers.
You have to say 1 to: -100 by: -1
I would expect it to populate the interval with the numbers or at least fail with an error. This does not look to me like normal behaviour.
(-100 to: 1) on the other hand work as expected.
Any thoughts on this issue ?
-- best, Eliot