From: Nobuyoshi Nakada <nobu@...>
Date: 2009-03-28T14:30:23+09:00
Subject: Re: Sorting decimal index numbers?

Hi,

At Sat, 28 Mar 2009 13:04:43 +0900,
Matthias Reitinger wrote in [ruby-talk:332318]:
> > If the second half can be any length, though, you'll have to determine
> > the maximum length first, and change that "100" multiplier accordingly.
> 
> Either that or use arrays as sort keys:
> 
>   arr = arr.sort_by do |x|
>     x.split(".").map {|i| i.to_i}
>   end

enc/depend file in 1.9 has more generic code.

  alphanumeric_order = proc {|e| e.scan(/(\d+)|(\D+)/).map {|n,a| a||[n.size,n.to_i]}.flatten}

But this fails if strings start with digit and strings start
with non-digit are mixed.  In such case, this is safer.

  alphanumeric_order = proc {|e| e.scan(/(\A\D*|\G\D+)(\d+)/).map{|a,n|[a,n.size,n.to_i]}.flatten}

-- 
Nobu Nakada