From: Peter <Peter.Vanbroekhoven@...>
Date: 2003-11-26T08:45:54+09:00
Subject: Re: Range does not take an Range object.

> class Range
>
>   alias_method :old_include?, :include?
>
>   def include?(obj)
>     if obj.is_a? Range

>       #lb1 = first.succ
        lb1 = first

>       ub1 = exclude_end? ? last : last.succ

>       #lb2 = obj.first.succ
        lb2 = obj.first

>       ub2 = obj.exclude_end? ? obj.last : obj.last.succ
>       (((lb2 <=> lb1) >= 0) && ((ub1 <=> ub2) >= 0))
>     else
>       old_include? obj
>     end
>   end
>
>   def intersect?(obj)
>     lb1 = first.succ
>     ub1 = exclude_end? ? last : last.succ
>     lb2 = obj.first.succ
>     ub2 = obj.exclude_end? ? obj.last : obj.last.succ
>     if (lb2 <=> ub2) > 0 then
>       false
>     elsif (lb1 <=> ub1) > 0
>       false
>     else
>       (((ub1 <=> lb2) >= 0) && ((ub2 <=> lb1) >= 0))
>     end
>   end
> end