!standard 15.45                                     09-10-12  SI99-0014-1/04
!standard 17.21
!class binding interpretation 06-04-20
!status ARG Approved  9-0-2  06-06-10
!status work item 06-04-20
!status received 06-02-13
!priority High
!difficulty Easy
!qualifier Omission
!subject Generalize A_Formal_Package_Declaration_With_Box

!summary

Add comments or notes to ASIS users regarding A_Formal_Package_Declaration_With_Box.

!question

The Amendment (Ada 2005) generalizes the actual part of a generic formal package;
should ASIS comments be updated to specify the results of passing this declaration to 
applicable subprograms? (Yes.)

!recommendation

(See summary.)

!wording

[Note: This wording depends on A_Box_Expression kind, added in SI99-0009.]

ASIS notes/comments for ASIS 17.21
* Asis.Expressions.Formal_Parameter may return An_Others_Choice for a
  unnormalized A_Generic_Association argument.

* If a formal_package_association contains a box, then the corresponding
  unnormalized A_Generic_Association element contains an Expression_Element
  with expression kind A_Box_Expression as its
  Actual_Parameter part. The normalized A_Generic_Association contains either
  a default parameter or an Expression_Element with expression kind
  A_Box_Expression.


!discussion

Recommended by Sergey I. Rybin on 06-02-13, see "!appendix" section.

!appendix

Subject: Summary of the proposals for updating the ASIS Standard for Ada 2005
From: Sergey I. Rybin
Date: Mon, 13 Feb 2006 13:55:06 +0300

Formally the ASIS revision process is supposed to be started only after
finishing all the technical work with the new revision of the Ada Standard,
but I think we can start some preliminary technical work with new ASIS
definition already now (all the changes in Ada definition are stable
enough to start the ASIS revision).

At AdaCore we have developed a draft version of the new ASIS specification
and most of the proposed changes are already implemented in the latest
version of GNAT/ASIS technology. The attached file contains the summary
of the changes in the ASIS Standard we have made to adopt the new Ada
features. The interesting thing I've realized when working on
our draft of the new ASIS specification is that if we would like
to keep the upward compatibility as much as possible and if we
would like to keep changes as small as possible,
the new Ada definition gives us very limited freedom in making changes
in the ASIS spec. It does not mean that we think that our proposals
are the only possible solution for ASIS 2005, but it gives us some
hope that we can do ASIS revision for Ada 2005 fast enough.

There is quite a natural mapping of the proposed changes in the ASIS
specification onto the existing set of Ada Issues used for Ada revision,
and the attached file is structured and ordered by AIs. The only
exception is the new values in the ASIS Element Classification needed
to represent the new Ada 2005 predefined attributes and pragmas (of course,
this could be also mapped onto AIs, but I do not think that it would make
sense, because this is the easiest and completely straightforward part
of the ASIS revision).

My main goal of sending this ASIS 2005 Draft summary is to start
the ASIS 2005 discussion. The document itself would hardly be a convenient
background for this discussion - we will have at least split it on
changes related to different language issues, we will also have to
find a way for documenting the revision discussion, probably we
may need a separate mailing list for it. But let's get started!

Sergey Rybin

.....

------------------------------------------
-- AI-317 Parameters of formal packages --
------------------------------------------
RM-06 12.7

* A_Formal_Package_Declaration_With_Box is added to the list of appropriate
  kinds for Asis.Declarations.Generic_Actual_Part - in Ada 05 it has
  parameters!

* Asis.Expressions.Formal_Parameter may return An_Others_Choice for a
  non-normalized A_Generic_Association argument;

* If a formal_package_association contains a box, then the corresponding
  non-normalized A_Generic_Association element contains Nil_Element as its
  Actual_Parameter part. The normalized A_Generic_Association contains either
  a default parameter or Nil_Element;

* We need a note in the ASIS Standard saying that in ASIS 2005
  A_Formal_Package_Declaration_With_Box is just a particular case of
  A_Formal_Package_Declaration, so all these two values should do together and
  be treated in the same way in most of the cases;

* We should consider the possibility of adding a new value to the ASIS Element
  classification for representing formal_package_association

****************************************************************