Re: [boost] Fw: Is there interest for iterator based conversion library? attempt #2

From: Shunsuke Sogame (mb2act_at_[hidden])
Date: 2006-07-20 11:32:25

Alexander A Potocki wrote:
> Shunsuke Sogame wrote:
>> Your code looks similar to Boost.Serialization Data Flow.
>> http://www.boost.org/libs/serialization/doc/dataflow.html
> 
> Yes, something is similar. As Dataflow as my library provide the set of 
> basic transformation primitives and give possibility to compose them to 
> create a complex compound converter.
> 
> But there are several distinctions.
> 
> 1 Create and instantiation of conversion entity in my library takes place in 
> the same time. Dataflow at first create compound iterator type and then 
> instantiate it. Such instantiation is simple and not clear.
> 
> 2 My library provides as input as output conversion iterators, but Dataflow, 
> it seems, provides only input iterator. Taking in mind "outputness" or 
> "inputness" of iterator  I distinguish transformation algorithms for 
> concrete conversion. For output iterator it's one, for input iterator it's 
> slightly (or not slightly) other.
> 
> 3. Shifting operation is not clear at all in Dataflow.
> 
>> But, we have now Boost.Range.
>> Assume 'range_copy(rng,it)' just calls
>> 'std::copy(boost::begin(rng),boost::end(rng),it)'.
>>
>>     range_copy(make_u32_to_u8_iterator_range(src), it);
>>
>> There is no typedef's.
>> You can look into <boost/regex/pending/unicode_iterator.hpp>, which
>> shows such implementations.
> 
> It's not clear for me. range_copy  is a good method, but 
> make_XXX_to_YYY_iterator_range will be implemented using the same typedefs. 
> And what is more how many make_ZZZ functions will be provided? I guess there 
> are very many combinations of possible XXX and YYY.

Sorry, I maybe overlooked what you made.
Trotter already(almost?) seems to achieve what I meant.
If I borrow the range-adaptors syntax from
        http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1871.html ,
Trotter might be written as:

     range_copy(
         utf16string|trotter_coded(cvt::utf16() >> cvt::utf8()),
         std::back_inserter(result)
     );

Actually I tried to write such a wrapper for trotter.
(But I failed. I have to look into trotter more. :-)

-- 
Shunsuke Sogame