Infinity in Ruby

I learned this from a post today:

irb(main):001:0> Infinity = 1/0.0
=> Infinity
irb(main):002:0> (0..Infinity).include?(100000000000000)
=> true
irb(main):003:0> (0..Infinity).include?(-1)
=> false
irb(main):004:0> (-Infinity..0).include?(-1)
=> true
irb(main):005:0> (-Infinity..0).include?(-100000000000000000000)
=> true
irb(main):006:0> (-Infinity..0).include?(1)
=> false
irb(main):007:0> everything = -Infinity..Infinity
=> -Infinity..Infinity
irb(main):008:0> everything.include? 0
=> true

But ruby is not like haskell, which eval lazily - so don't try everything.to_a[0..100] :)