[boost] Re: libs/iterator/doc/iterator_facade.html typo?

From: David Abrahams (dave_at_[hidden])
Date: 2004-02-12 12:43:23

"David Bergman" <davidb_at_[hidden]> writes:

> David Abrahams wrote: 
>
>> Angus Leeming <angus.leeming_at_[hidden]> writes:
>> 
>> > David Abrahams wrote:
>> >>> In the section "Template Arguments for iterator_facade" is the 
>> >>> subsection "CategoryOrTraversal". I suspect that should be 
>> >>> "CategoryOfTraversal" (s/Or/Of/).
>> >>>
>> >>> The iterator_adapter docs spell it "CategoryOrTraversal" too.
>> >> 
>> >> No, the spelling is as intended.
>
> The naming of the implementation, and the (informal, so far?) proposal by
> you, Siek and Witt (sp?), is a bit misleading.

Well, it seems as though you were misled somewhere along the way.

> A few comments/suggestions:
>
> 1. A group of concepts should be called either "group" or "category"
> (I think you stick to the former most, of not all, of the time)
> consistently in both proposal and implementation.

I have no idea what you're referring to.  Maybe you should
specifically point to text you think should be changed, and why.

> 2. Why is one concept group (i.e., one part of the dichotomy) called
> "category" 

Because that's what the existing standard calls it.

> and the other "traversal." 

Because that's what it describes.

> Potential confusion ahead... I propose
> "access" and "traversal," 

Existing category tags do not describe just access.  They describe a
combination of access and traversal, as you can see by reading
http://www.boost.org/libs/iterator/doc/new-iter-concepts.html

> since I see no more of a "categorically" intrinsic property in one
> group than the other, i.e., labeling the access dimension as
> categorical is a bit unfair to the poor traversal dimension ;-)

It would be, but we're not doing that.

> Furthermore, connected to (1), category is often used to denote a
> group of concepts, so I understand Angus' confusion.

I don't know what you're talking about again.

> 3. In the traversal group/category of concepts, they should either *all*
> include the lexeme "traversal" or *none*. 

Probably a good idea.  We made that change to the tags, but not to
the concept names.

> In fact, I propose to completely skip the "traversal" in the concept
> names.  The only potential conceptual hurdle is the "access" in
> "random_access" (or RandomAccessIterator) that can be confused with
> the access-related group of concepts...

Bad idea, IMO. incrementable_tag, for example, shouldn't be reserved
by an iterators library; it could apply to lots of things.

> 4. The access group of iterator concepts: what is so "iterative"
> about them?  I.e., are they not general proxy concepts, with
> potential applications in smart pointers and other proxy situations?

...and your point is...?

They were designed so that they could be used independently from
traversal.

> Comment (4) above is a bit whimsical, admittedly, and I do understand the
> benefit of sticking to Iterator in the discussions, to easier combine with
> existing notions and concepts in STL.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com