From: Sam Gentle <sgentle@...>
Date: 2005-11-26T08:49:46+09:00
Subject: Fun with ranges!

So I was messing around today trying to find out whether there was a
viable way to cram unbounded lists into the Range implementation when
I stumbled on this...

irb(main):001:0> inf = 1.0/0.0
=> Infinity

irb(main):002:0> 1..inf
=> 1..Infinity

Hoorah! But not just that.

irb(main):003:0> 'a'..inf
=> "a"..Infinity

Hold on a second, I said to myself, that doesn't make any sense... inf
is a Float and "a" is a string! That's when I discovered ruby's
dastardly secret:

irb(main):004:0> 'a' <=> 3
=> false
irb(main):005:0> 3 <=> 'a'
=> nil

And hence:

irb(main):006:0> 'a'..3
=> "a"..3
irb(main):007:0> 3..'a'
ArgumentError: bad value for range
        from (irb):7

Zounds,

Sam