Re: default formal parameters in generic declarations

[Eric Hughes <eric.eh9@gmail.com>]

On Mar 6, 2:32 am, Georg Bauhaus <rm.tsoh.plus-
bug.bauh...@maps.futureapps.de> wrote:
> By way of speculation, can nesting, to the extent it is absent from C++,
> lead to at least a partial solution of this problem?
[example deleted]

The technique you outlined is applicable insofar as name space
manipulation goes, yes.  I note here that your example uses a formal
default subprogram.

The problem, really, is that an aspect is larger than a single
function.  An aspect has state, a state that augments the state of the
package for which it is an aspect.  State, in Ada, is captured in
types.  For example, a null aspect has no state, represented by a null
record.  Ada currently has neither formal defaults for types or
packages; I've been focusing on packages.  If Ada had a syntax for a
formal default type, I might be able to shoehorn everything through
that, at the cost of some contortion of syntax, but that's not
possible either.

> I'm noting all this only because I should think there is some value
> in nesting that, just maybe, is easily overlooked.

Certainly the point about nesting you make is true.  It's one way of
addressing the self-reference problem.  Yet it doesn't rise to a
complete approach.

Eric