From: "David A. Black" <dblack@...>
Date: 2005-11-26T09:23:44+09:00
Subject: Re: Fun with ranges!

Hi --

On Sat, 26 Nov 2005, Sam Gentle wrote:

> 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

What version of Ruby are you using?

$ ruby -ve '"a"..3'
ruby 1.8.3 (2005-09-21) [powerpc-darwin8.3.0]
-e:1: warning: useless use of .. in void context
-e:1: bad value for range (ArgumentError)


David

-- 
David A. Black
dblack@wobblini.net