Re: Manifesto against Vector

["Alexander E. Kopilovich" <aek@VB1162.spb.edu>]

Matthew Heaney wrote:

> it's a good thing the vector isn't named "Unbounded_Array",
> since it's not an unbounded array.  (The vector uses an unbounded array
> as a model, in order to describe the semantics of the abstraction, but
> of course that doesn't mean the vector is an unbounded array.

Apparently the name "Unbounded_Array" implies for you a particular method of
implementation; probably you think that the "Array" part of this name hints
on that the whole container occupies contiguous chunk of memory (or, perhaps,
several chunks, with many elements of the array in each). But this is just
your personal association, and I don't think that this association is too
widespread.

Anyway, the method of implementation of this container doesn't matter much
for a user, because if it did matter then the standard container probably
should not be used at all - according to general presumption for intended use
of the whole Container Library.

>  In fact,
> at least two compiler vendors will not be using an unbounded array as
> the representation of their vector implementation.)

There aren't too many options for those compiler vendors - I guess that they
will use unbounded array of accesses to the objects in container. In Delphi's
VCL the container implemented in this way is called List - and there were no
complaints among Delphi programmers regarding this name. By the way, the name
Flexible_Array (inspired by Algol-68) would be totally neutral regarding an 
implementation.

The essence of the problem at which I pointed, is not that the particular
name (Unbounded_Array) was not chosen, but in that the chosen name (Vector)
has another predefined meaning in several application domains (which are
among few Ada-friendly ones), And that this name will be in the standard.




Alexander Kopilovich                      aek@vib.usr.pu.ru
Saint-Petersburg
Russia