Re: gsl container designs

[Brian Gough <bjg at gnu dot org>]

At Tue, 24 Nov 2009 17:54:46 -0700,
Gerard Jungman wrote:
> Here are header files for a couple different approaches to containers.
> I didn't bother with any implementations; it seems obvious how to
> implement most of these functions.
> 
> The designs are not complete, but they express most of
> the important stuff.

Thanks for the document, I have studied the designs this week.  It
seems that changing to design 1 / 1u / 2 would be trading one set of
problems for another.  Looking at each case, the change doesn't seem
sufficient to justify the compatibility cost.

Regarding the introductory points.

2a+b) While we may have had some kind of goal of supporting C++ I
don't think it's worth encouraging that today as the gap between the
languages has widened so much since the start of the project.

3) Non-levelised types.  These seem to be the price for type safety.
In terms of the look/feel, expressions like &row.vector and
&column.vector don't seem too unnatural to me.

4) I think this can be fixed in the current framework.

5) Since row-major was in the original design it's too much of a break
to change that.

I think the most realistic way forward is to add a multiarray type,
with rank-1, rank-2 and rank-N versions, in the existing framework and
use non-levelised types for const/non-const views to preserve
type-safety.

-- 
Brian Gough