From: "Steve [RubyTalk]" <steve_rubytalk@...>
Date: 2005-12-02T05:33:19+09:00
Subject: Re: String + Range = Strange

Bob Showalter wrote:
> The point is that even though "aa".."b1" is a valid range, calling 
> succ repeatedly from the starting point will never yield the endpoint.

This, I think is the crux of the matter.  It seems to me that given that 
if "aa".."b1" is a valid range, that calling calling succ on "aa" should 
logically eventually reach "b1".  I understand that in Ruby, today, it 
doesn't.

I suppose I can get the behaviour I expect by doing something like this.

class String
  def succ
    s=String.new self
    (s.length-1).downto 0 do |i|
      s[i]=(s[i]+1)&0xff
      return s unless s[i]==0
    end
    1.chr.concat s
  end
end

Is there any good reason that this isn't the default behaviour for succ 
- given that Ruby claims an objective is to have "sensible defaults"?  I 
can see a justification for having a method defined how String#succ is 
defined today - but I don't see why it has to be as the default succ 
method... especially since it gives such counter-intuitive results when 
used with ranges.  Alternatively - I suppose - it might make sense if 
ranges didn't use succ?

Ranges in regexps don't work the same "smart" way - wouldn't consistent 
default behaviour be far  preferable?