Re: [boost] [proto] new version, breaking changes

From: Eric Niebler (eric_at_[hidden])
Date: 2007-05-21 16:13:40

Steven Watanabe wrote:
> AMDG
> 
> Eric Niebler <eric <at> boost-consulting.com> writes:
> 
>>> If you want to change both, a possibility would when (for if_) and  
>>> unless (for not_).
>> Interesting. All, any, when, and unless are not unreasonable. I know you 
>> retracted this suggestion in another message, but I want you to bring it 
>> up again when proto is under review. Naming is super-important, and I 
>> want more feedback on this issue. I'll remind you when the time comes.
>>
> 
> Another possibility is to use separate namespaces
> proto::operators::or_
> proto::control::or_

I thought about that, and it's not unreasonable, either. It might cause 
less confusion. However, the different or_'s will often be used 
together, making qualification a requirement. Compare the following 
(assumes using namespace proto;):

   struct MyGrammar
     : control::or_<
           operators::or_<_,_>
         , operators::bitor_<_,_>
       >
   {};

to

   struct MyGrammar
     : or_<
           logical_or<_,_>
         , bitwise_or<_,_>
       >
   {};

IMO, eliminating the operators:: namespace would be better. This isn't 
half bad:

   struct MyGrammar
     : control::or_<
           or_<_,_>
         , bitor_<_,_>
       >
   {};

But control::or_ is likely to be more common than or_ (the operator), so 
the Huffman coding is lousy. Gah, naming is hard! Opinions? Maurizio? 
Joel? Hartmut?

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com