From: Joel VanderWerf <vjoel@...>
Date: 2005-11-23T17:18:10+09:00
Subject: Re: [BUG] string range membership

Brian Schr�der wrote:
> I'd argue that it is not a bug, as there is no unique isomorphie from
> strings to integers. Some well known functions would be hex, octal and
> decimal encoding. I.e. '2' ... '10' could be understood as 2 ... 8, or
> 2 ... 16 or 2 ... 10 or error ... 2 depending on the base.
> 
> Only you can now what the string means, so convert it to an integer
> and do the range test on integers.

I was going to make that argument, but I realized that #each (by way of
#succ) *does* have some extra knowledge (or assumptions) about strings,
and it's pretty smart:

irb(main):003:0> ('1.1'..'10.1').each {|s| p s}
"1.1"
"1.2"
"1.3"
"1.4"
...
...
"9.6"
"9.7"
"9.8"
"9.9"
"10.0"
"10.1"
=> "1.1".."10.1"
irb(main):004:0> ('1.6.4'..'1.8.3').each {|s| p s}
"1.6.4"
"1.6.5"
"1.6.6"
"1.6.7"
"1.6.8"
"1.6.9"
"1.7.0"
"1.7.1"
"1.7.2"
"1.7.3"
"1.7.4"
"1.7.5"
"1.7.6"
"1.7.7"
"1.7.8"
"1.7.9"
"1.8.0"
"1.8.1"
"1.8.2"
"1.8.3"
=> "1.6.4".."1.8.3"

I guess it is just impractical for Range#member? to test using #succ.

-- 
      vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407