From: Austin Ziegler <austin@...>
Date: 2002-07-03T22:01:53+09:00
Subject: Re: (0..3) == (0...4) returning false?

On Wed, 3 Jul 2002 18:13:52 +0900, David Alan Black wrote:
> On Wed, 3 Jul 2002, Yukihiro Matsumoto wrote:
>> on 02/07/03, "Juergen Katins" <juergen.katins@web.de> writes:
>>> 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
>>> (0...4).each (which means 3.2 is NOT included in (0...4) ). It
>>> is a little bit illogical. Look out!
>> I'm working on it in 1.7, but still no firm decision. If you have
>> any comment, proposal, and idea, tell me freely.
> My instinct would be to expect:
> 
> aRange === n iff aRange.to_a.include?(n)
> 
> (which probably ends up being the same as Juergen's #each test)

I think that your test would result, however, in (0..3) == (0...4)
and I'm not sure that's good. Although I haven't yet had a need to
use ranges in this way, I actually think that the current behaviour
is proper such that each covers the whole numbers.

I might consider a variation on each for ranges to be nice:

(0...4).each(0.5) { |x| print "#{x}, " } #
    => 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5,

It'd be nicer if you could specify the step as part of the creation
of the range, but I'm really not sure how you'd do that.

-austin
-- Austin Ziegler, austin@halostatue.ca on 2002.07.03 at 08.56.13