Re: Copying rows in a two dimensional array.

[Jean-Pierre Rosen <rosen@adalog.fr>]

Jerry a �crit :
> I've never understood why Ada does not allow slicing in
> multidimensional arrays. What are the safety issues involved? And how
> is it safe to force the programmer into ad hoc methods?
> 
One-dimensional slices are simple and efficient. Multidimensional slices
are a can of worms.

I guess you are thinking about rectangular slices. But why stop there? A
slice comprising the main diagonal and the diagonal above and below can
be very useful for some calculations. Or a slice which is the triangular
part of the upper half...

AFAICT, Fortran-99 does provide this - and the syntax is so complicated
that nobody uses it. And implementation is also a nightmare.

When designing a programming language, you have to stop at some point.
The ratio (cost of implementation) / usefulness is a good measure for
this. I think the ratio was simply to high for this feature.

-- 
---------------------------------------------------------
           J-P. Rosen (rosen@adalog.fr)
Visit Adalog's web site at http://www.adalog.fr