Re: [boost] Rave for proposed Boost.Local (functions)

Subject: Re: [boost] Rave for proposed Boost.Local (functions)
From: Gregory Crosswhite (gcross_at_[hidden])
Date: 2011-02-05 15:59:55

On 2/5/11 12:35 PM, Joel de Guzman wrote:
> Look, let us please stop this syntax nonsense.

It isn't nonsense.  Inline Phoenix functions have a special syntax which 
does not come naturally but requires training to use and understand.  
This is a fact.

Having said that, I think that you are misconstruing us as saying that 
this is a bad thing.  Nobody here is claiming that this is a bad thing 
--- and in fact, I think that the syntax is very impressively designed 
because of the way it allows one to construct very nice-looking 
functions within the limitations of being based on C++!  All we are 
saying that it isn't always a good thing, which I am sure you agree with.

Furthermore, I agree with Lorenzo's sentiment that I wish I understood 
it better, and if I have the time I may see if I can learn to be more 
effective in using it.  :-)

> As mentioned,
> phoenix can have all those above (pure c++ function syntax,
> local classes, local variables, etc.) in the form of offline
> phoenix::function.

Yes, one can do that, but looking at the documentation (and please 
correct me if I am mistaken!) it looks like writing such a function is 
equivalent to writing a function object but with even more boilerplate 
to make it lazy.  I am sure that there are many situations where this is 
incredibly useful (in particular because it means that you don't need to 
use boost::bind, which is very nice!), but by itself it does not seem to 
me that it provides the same features as Boost.Local.  This, again, is 
not a criticism;  the whole point of this discussion was just to show 
that Boost.Local is complimentary to Boost.Phoenix rather than being 
made redundant by Boost.Phoenix, that's all.

Having said that, you have mentioned that with a few macros one could 
construct pheonix::functions without needing the extra boilerplate, just 
as Boost.Local does.  If this is the case, then I would look forward to 
seeing it.  I am certainly not against using Boost.Phoenix when it is 
the best tool available.  :-)

> At any rate, I repeatedly say: I am not against Boost.Local. As I
> said, in as much as we have BOOST_FOREACH and std::bind, I see no
> reason why we can't have Boost.Local. 

Great, then we are actually in agreement!  If you think that you or 
Boost.Phoenix is being criticized, then I think that there might just be 
a miscommunication at work here, since I have been attempting (perhaps 
unsuccessfully) to make clear that at least for me there is only 
admiration for Boost.Phoenix, not loathing, and I suspect that Lorenzo 
feels the same way.  :-)

Cheers,
Greg