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!standard 18.40          06-04-20 SI99-0013-1/01
!class binding interpretation 06-04-20
!status work item 06-04-20
!status received 06-02-13
!priority High
!difficulty Easy
!qualifier Omission
!subject Add support for exceptions with string expressions.
!summary
Adds support for retrieving the string expression optionally associated with an exception.
!question
The Amendment (Ada 2005) adds the capability to associate a string expression with an exception; should these be accessible from ASIS? (Yes.)
!recommendation
(See summary.)
!wording
* Add a new query to Asis.Statements after Raised_Exception, , ASIS section 18.40
function Associated_Message -- 13.3(2)
(Statement : Asis.Statement)
return Asis.Expression;
------------------------------------------------------------------------------ -- Statement - Specifies the raise statement to query -- -- Returns the string expression that is associated with the raised -- exception and follows the WITH keyword in the raise statement -- -- Returns a Nil_Element if there is no string expression. -- -- Appropriate Statement_Kinds: -- A_Raise_Statement -- -- Returns Element_Kinds: -- Not_An_Element -- An_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-361 Raise statement with string expression --
---------------------------------------------------
RM-06 11.3

* Add a new query to Asis.Statements:

   function Associated_Message
      (Statement : Asis.Statement)
       return      Asis.Expression;

------------------------------------------------------------------------------
--  Statement - Specifies the raise statement to query
--
--  Returns the string expression that is associated with the raised
--  exception and follows the WITH keyword in the raise statement
--
--  Returns a Nil_Element if there is no string expression.
--
--  Appropriate Statement_Kinds:
--       A_Raise_Statement
--
--  Returns Element_Kinds:
--       Not_An_Element
--       An_Expression

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