From: Daniel Schierbeck <daniel.schierbeck@...>
Date: 2007-02-21T08:46:14+09:00
Subject: Re: [Facets] Range#overlap?

On Wed, 2007-02-21 at 08:00 +0900, Daniel Finnie wrote:
> I think your implementation is cleaner however the endpoints of a Range 
> do not have to implement #succ.
> 
> class Range
>    def span? other
>      include? other.first and
>        (other.exclude_end? ? other.last < last : other.last <= last )
>    end
> end

I've tried that implementation, but i doesn't work if you consider this
valid:

  (4..8).span? 6...9

Since 6...9 yields the same values as 6..8. Or am I wrong to expect the
above?

I know #last doesn't have to support #succ, and I'd be happy to see a
better implementation. Challenge? ;)


Cheers,
Daniel