Re: [boost] [regex and string algo] again strange split behaviour

From: Thore Karlsen (sid_at_[hidden])
Date: 2005-07-13 12:48:55

On Wed, 13 Jul 2005 19:00:12 +0200, "Jan Hermelink"
<Jan.Hermelink_at_[hidden]> wrote:

>> It looks more like a bug than by design if you ask me.

>I don't think so - this behaviour is specified in the standardization
>proposal.
>To quote from
>http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2003/n1429.htm,
>Chapter "RE.8.2 Template class regex_token_iterator":
>
>"If the end of sequence is reached (regex_search returns false), the
>iterator becomes equal to the end-of-sequence iterator value, unless the
>sub-expression being enumerated has index -1: In which case the iterator
>enumerates one last string that contains all the characters from the end
>of the last regular expression match to the end of the input sequence
>being enumerated, provided that this would not be an empty string."
>
>!!! "provided that this would not be an empty string" !!!

How about this string: "/abc/abc". Would this result in "", "abc",
"abc"? Yet "abc/abc/" would result in "abc", "abc"? That seems terribly
unbalanced to me, and this is not the behavior I would expect.

>> I don't agree.
>> I think this is counterintuitive, both for string_algo and regex

>May be, but the above described behaviour has a good change to be
>standardized, and boost::split() should do the same thing.

I still don't agree based on that argument. Two wrongs don't make a
right. I'd like to know the reason why the empty string is explicitly
excluded in the paragraph above, though.

-- 
Be seeing you.