From: brabuhr@...
Date: 2009-08-20T11:53:25+09:00
Subject: Re: Bizarre Range behavior

On Wed, Aug 19, 2009 at 10:27 PM, Daniel DeLorme<dan-ml@dan42.com> wrote:
> Yukihiro Matsumoto wrote:
>> In message "Re: Bizarre Range behavior"
>>    on Tue, 18 Aug 2009 21:31:38 +0900, Daniel DeLorme <dan-ml@dan42.com>
>> writes:
>>
>> |That sounds nice and consistent, but why limit ourselves to numbers?
>> |     ("y".."aa").to_a
>> |should then generate ["y", "z", "aa"] since that's what String#succ
>> |generates. Sounds like this could snowball into a nightmare of
>> |incompatible changes.
>>
>> Indeed.  The issue is that it's not easily distinguishable whether
>> a sequence using #succ from a string reaches to another, or not.
>> If there's affordable scheme to implement, I'd love to check in.
>
> While investigating this I came across:
>>> "\0019".succ
> => "\00110"
>
> I expected the result to be "\0020"; is that a bug?

I don't think so, the octal escape is 'eating' the "1" and leaving "9"
to succ to "10":

$ ruby -v -e 'p "\0019".succ'
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\00110"

$ ruby -v -e 'p "\019".succ'
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\00110"

$ ruby -v -e 'p "\19".succ'
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\00110"

$ ruby -v -e 'p "\1".succ'
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\002"

$ ruby -v -e 'p "\119".succ'
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\t10"

$ ruby -v -e 'p "\0119".succ'
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\t10"

$ ruby -v -e 'p "\00119".succ'
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\00120"

$ ruby -v -e "p '\0019'.succ"
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\\0020"

$ ruby -v -e "p '\00 19'.succ"
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\\00 20"

$ ruby -v -e 'p "\01 19".succ'
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
"\001 20"