Re: [boost] Re: [Formal review] Collection Traits library

From: Aleksey Gurtovoy (agurtovoy_at_[hidden])
Date: 2004-05-07 08:09:18

David Bergman writes:
> Alexey wrote: 
> 
> > > > Well, I don't have an ultimate answer, but here's a 
> > couple of candidates:
> > > > 
> > > >     Range
> > > >     Iterator Range
> > > >     View
> > > >     Series
> > > >     Succession
> > > 
> > > These terms are not synonymous. 
> > 
> > I didn't imply they were. 
> 
> If you knew they were not synonymous, yet you suggest them as name
> candidates for a specific concept. This gives me an uneasy feeling of (at
> least your notion of) the concept.

I don't see why. Would you have a problem with putting "Cursor" and 
"Iterator" on the same list, if you were to name a beast with 'current', 
'next' and 'done' methods? They are not synonyms either.

>  
> > > Some imply an ordering, others do not.
> > 
> > Depending on your definition of ordering none or all of them do.
> 
> Ordering should be intrinsic not coincidental.

How's that related to my statement?

> > > The standard's "Sequence" concept has a definite ordering,
> > 
> > Doesn't matter what standard's "Sequence" concept has; for 
> > one, it's a dead concept. A "sequence" as a word in a 
> > programmer's dictionary doesn't imply a definite ordering in 
> > the sense in which the term is used in the standard; "random 
> > sequence" is a perfect, well, sequence. 
> > 
> > > neither
> > > "Collection" not "Container" imply any ordering.
> > 
> > They all guarantee that the 'end' reachable from 'begin', 
> > that is, that by repeatedly incrementing 'begin' you'll go 
> > through a range of successive elements until you reach the 
> > 'end'. I don't see anything inherent in the word "sequence", 
> > or, for that matter, "series" or "succession" that implies 
> > more than just that. Again, "random series" or "random 
> > succession [of something]".
> 
> Those are coincidental orderings. Sequences have an intrinsic ordering,
> being part of the conceptual structure of the entity.
> 
> Since a sequential machine only executes one instruction at a time, ALL
> structures should then be considered ordered according to you, no?

If every instruction in a program is executed just once, it definitely
imposes an order relationship on them.

> I mean, it all starts and ends ;-)
>  
> > > My dictionary defines collection as "an accumulated assortment of 
> > > things of a particular type" - which sounds ok for this concept. 
> > > There's no implication of containing or owning the things, 
> > so the fact 
> > > that VB (or CS in general) have used the term to describe 
> > ownership is 
> > > a fault in VB, not the word!
> > 
> > Programming is all about communication; it doesn't matter 
> > what the original meaning of the word is/was; what matters is 
> > what your teammates think of when they hear it. I'm claiming 
> > that most people think of collection classes, i.e. containers 
> > with storage.
> 
> I think on a quite different beast when I hear "sequence" (at least from a
> senior CS and/or IT individual) than when I hear "collection." 

Which was exactly my point.

[...]

> > 
> > Does it? Seems like a supporting case to me:
> > 
> >     virtual class Collection[T] inherits Any
> >         ** insert a T into the collection
> >         insert(t:T) : Self[T] is deferred
> >         ^^^^^^^^^^^
> > 
> > If that doesn't imply storage, I don't know what does.
> 
> Could you not say that about any altering operation? That any altering
> operation on a notion implies storage?

No. Changing range boundaries doesn't, for instance. But again, I don't see
how it's related to my point.

> I think you have a far too pragmatic view on these things, which does not
> rhyme very well with proper (GP) conceptualization.
>  
> > > There Sequence is an ordered Collection, which fits both 
> > the STL terms 
> > > and the proposal for "Collection Traits".
> > > 
> > > IMHO the example of range_view(0,100) could happily be called a 
> > > ForwardCollection - there's no containment but there's a definite 
> > > ordering.
> > 
> > My problem is that Collection _does_ imply storage for me, 
> > and the connotation is continuously reinforced by a numerous 
> > examples from all around.
> 
> I probably agree that this specific concept, Collection, bears a strong
> storage component, 

Great!

> but do you consider even proxy structures to have "storage."?

What's a proxy structure? 

--
Aleksey Gurtovoy
MetaCommunications Engineering