From: Nikodemus Siivola <tsiivola@...>
Date: 2002-07-03T20:20:23+09:00
Subject: Re: (0..3) == (0...4) returning false?


On Wed, 3 Jul 2002, Yukihiro Matsumoto wrote:

> > Although (0...4) === 3.2   produces true (which means 3.2 is
> > included in (0...4) ) 3.2 is no element of (0...4) in terms of

> I'm working on it in 1.7, but still no firm decision.
> If you have any comment, proposal, and idea, tell me freely.

You want wishlists? I have wishlists :-)

1) Ranges as sets of numbers:

  Set.new(0...4)      === 3.2 #-> false
  Set.new(0...4, 0.1) === 3.2 #-> true

2) Ranges as ranges of floats and integers:

  Range.new(0...4) === 3.2 #-> true

So, the current behaviour is correct, since iteration over a
floating range should default to a step of one, but I should definable
at creation:

 Range.new(0...2, 0.5) === 1.3 #-> true
 Range.new(0...2, 0.5).to_ary == [0.0, 0.5, 1.0, 1.5, 2.0]

So a range object would case-match against any number between the two
extremes, but would be iterated over at a definable step and use the same
step in array / set conversion.

3) A Set-class in the core.

 -- Nikodemus