Re: [boost] [regex and string algo] spliting empty string (was: again strange split behaviour)

From: Thore Karlsen (sid_at_[hidden])
Date: 2005-07-13 16:32:14

On Wed, 13 Jul 2005 23:08:19 +0200, Pavol Droba <droba_at_[hidden]>
wrote:

>> > Hi,
>> >
>> > This is an interesting observation. So it seems reasonable to drop
>> > back to 1.32 version.

>> The only reasonable thing is for split to return N+1 pieces for a string 
>> with N separators, if you ask me. :-) This is lossless in the sense that it 
>> allows you to reconstruct the original string. The non-reasonable behavior 
>> can easily be implemented on top of that, but not vice versa. 

>Reading your replies and thinking about it a little bit, I come to conclusion,
>that the definition above is realy to only reasonable one. That was actualy
>also the reason why I have altered the behaviour in this release. Beacuse
>I considered the former one as wrong.
>
>But now there is still issue about the empty string. I think, that both approaches
>- returning no token
>- returing one empty token 
>
>have some meaning.
>
>The second one is very similar to returnig an empty token at the end if the input
>string ends with a separator.
>
>The first one simply tells that nothing equals nothing. 
>Yet I prefer the second approach, since it is more on par with the current reasoning.
>
>Does anybody have some arguments/reasoning that can help here?

I agree that both have some meaning, but like you, I also prefer the
second approach. I think Peter brings up a good point when he says that
split should return N+1 pieces for a string with N separators. I feel
the same way about this, so I vote that you don't change anything.

-- 
Be seeing you.