Re: [boost] [spirit] New Header Structure [was Re: Proposal: Add Loki Library's SafeFormat to Boost:]

Subject: Re: [boost] [spirit] New Header Structure [was Re: Proposal: Add Loki Library's SafeFormat to Boost:]
From: David Abrahams (dave_at_[hidden])
Date: 2009-01-09 17:38:54

Let me say up front that I have a *lot* of sympathy for your experience
with the documentation not matching the code.  That sounds like a
serious problem.

on Fri Jan 09 2009, Markus Werle <numerical.simulation-AT-web.de> wrote:

> Since Spirit-1 is very important, I am happy to hear
> it will stay in boost for a looong time.
> I have so much code depending on spirit-1 
> I cannot afford a removal of spirit-1 from boost.
>
> I am not the only one.
> So you cannot deprecate the usage of Spirit-1,
> due to so many people using it around the world.

Well, yeah, he can... and he can do it without affecting anyone (other
than psychologically).  Deprecation merely announces an intention to
stop supporting the legacy technology someday.

> For me this library (which you call Spirit-2) is 
> something so fundamentally new, it should
> a) undergo some review (at least concerning the interface) 
> b) reside in its own directory

Well, Joel doesn't develop his library in a vacuum.  There's a strong
Spirit community that reviews all of his design decisions.  There's no
voting, of course, but I don't think that would be appropriate here.

>> This thread is about Robert's assertion that 
>> the new header structure causes breakage. 
>
> I think even in the absence of a minimal.cpp or
> other proof we should believe Robert who said
> that he had some trouble. He described it earlier
> in this thread.

Nobody doubts that Robert had some trouble, but I am not at all sure
whether to believe his diagnosis of the reasons for his trouble or
whether those reasons are still present in the released Spirit codebase
or just the pre-release code he was using.

> Would be nice to fix that using minimal.cpp, 
> but 
>
> if (!show_proof())
> {
>         no_problem_exists();
> }
> else
> {
>         fix_code();
> }
>
> is not the perfect code.
> I prefer:
>
> if (true)
> {
>         separate_the_two_libraries();
> }

The problem is that, without knowing what really went wrong, we have no
assurance that separate_the_two_libraries() will fix the problems.

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com