Revised 1 October 2001, Jim Moore, Convener
The 41st meeting of ISO/IEC JTC1/SC22/WG9 will be hosted by the SIGAda 2001 conference in cooperation with the National Body of the USA. Our host plans to provide morning refreshments.
The meeting will begin at 9:00 a.m. and is expected to adjourn at 1:00 p.m. At this time, the meeting room has not been identified.
The announcement and preliminary agenda for this meeting were circulated as N392.
The meeting is scheduled to begin at 9:00 am.
Clyde Roby has agreed to serve as meeting secretary.
The minutes of Meeting #40 appear in document N389. The document includes several corrections suggested by John Barnes and Randy Brukardt subsequent to Meeting #40.
[Agenda]
National Body Representatives:
WG9 Officers:
Other Attendees:
Those sending regrets include: Ted Baker, Ken Dritz, Don Sando, Jon Squire, Alfred Strohmeier, Joyce Tokar, Brian Wichmann
[Agenda]
I am very pleased to report that several participants in WG9 were recognized with major awards at the SIGAda conference. Allan Burns and Alfred Strohmeier received awards for "Outstanding Ada Community Contributions." Clyde Roby and Currie Colket received awards for "SIGAda Distinguished Service." It is notable that WG9 participants accounted for four of the five awards presented. The other award was given to Charles McKay.
The Technical Corrigendum to the Ada Reference Manual was published on 1 June 2001.
Alfred Strohmeier has made arrangements with Springer-Verlag for the hardcopy publication of a consolidated ARM. A manuscript has been submitted to Springer for publication by year-end.
WG9 has requested a subdivision of the Ada project to permit the preparation of an Amendment. The request was recently approved in a ballot by SC22. JTC1 has the right to review the approval but seldom intervenes.
The MITRE Corporation is seeking funding from the United States Department of Defense to pay for the services of an editor for the preparation of an Amendment to ISO/IEC 8652. It is envisioned that the process for contributing the draft document to WG9 will be similar to that used for the recent Corrigendum.
The UK national body was requested to prepare a recommendation for the future of ISO/IEC 13813 in collaboration with its editor, Don Sando. The report of the UK is included in the appendix to this agenda.
Later in this meeting, we anticipate a report from the HRG regarding progress on preparing a guide to the use of the Ravenscar profile.
At our Leuven meeting, we prepared a request that TR 15942 be made freely available on an appropriate ISO web site. Endorsement of our request is being balloted by SC22. The next step would be consideration by JTC1.
According to JTC1 directives, the members of Rapporteur Groups serve as representatives of their National Bodies. There may be some inconvenience in bringing our Rapporteur Groups into compliance with the directives. I have asked each RG Chair to prepare a list of members so that we can begin to examine the extent of the problem.
SIGAda has expressed some interest in establishing a Category C liaison with WG9. We will discuss this issue later in the meeting. I would like to enter into a similar discussion with Ada-Europe.
JTC1 recently considered proposals for restructuring. The approved changes were far more modest than some had anticipated. A new "workshop" mode of operation was approved. Later in this meeting, we will discuss possible use of this new mode.
The plenary meeting of SC22 was conducted 17-21 September 2001 in Kona, Hawaii. The Convener provided his annual report for consideration at the meeting. WG9's request for public availability of TR15942 was considered at the meeting and resulted in the authorization of a letter ballot which will result in a recommendation for JTC1 action. The meeting approved the requests from WG9 to confirm 13813 and withdraw 13814. (This will have the effect of "freezing" the status of 13813 until WG9 has the opportunity to formulate a plan for its future. The ballot authorizing preparation of an Amendment to 8652 closed just prior to the meeting; the amendment project was approved.
[Agenda]
The schedule for meetings #42 was approved at the Leuven meeting:
At the Leuven meeting, it was agreed that the current meeting would reconsider our traditional scheduling practice. The minutes from the Leuven meeting read as follows:
There was discussion of our custom of scheduling our meetings in conjunction with the SIGAda and Ada-Europe conferences. Tokar asks if it might be better to associate our meeting with non-Ada conferences in order to better reach out to other communities. Michell replies that the SIGAda and Ada-Europe conferences value our collocation with them because we attract some participants who might not attend otherwise. It was stated that the current arrangement minimizes travel expenses for WG9 participants. Tokar replied that associating with other conferences would provide us with more knowledge of other areas and greater exposure to those communities. Strohmeier said that we would need an overall strategy to make a change like this. Barnes remarked that we have some experience due to Ada-Europe's past association with the Eurospace conference. Ploedereder said that it would be helpful to have people knowledgeable about Ada at other conferences. For now, we decide to continue our current practice in scheduling meetings but to reconsider the issue at the next meeting of WG9.
The schedule for meetings #43 is proposed as follows:
[Agenda]
This is the "To Do" list for WG9. Some are informal action items assigned to various participants. Some are formal resolutions, which are not yet implemented. Some are suspense items awaiting action by other groups.
(Convener): Contact Prof. Alfred Strohmeier to determine if Springer-Verlag can publish the ARM.
Status: CLOSED. Prof. Strohmeier has reached an understanding with Springer to publish the ARM as part of the lecture notes series in November. Ada-Europe will probably distribute copies to its members. Implementing Resolution 40-5, the US send a copy of the manuscript of the consolidated ARM to Prof. Strohmeier for transmission to Springer.
(HRG Chair): Draft a New Work Item Proposal for the Technical Report providing guidelines and rationale for the use of the Ravenscar profile.
Status: OPEN. The spring 2001 meeting of the HRG confirmed that they wish to move ahead on drafting a Technical Report providing advice on the usage of the Ravenscar profile. They developed a list of contents and assigned an author to each section. They plan to develop a first draft within six months. They plan to bring an NP to the WG9 meeting following completion of the initial draft.
[See Report of HRG]
(Convener): Send electronic copy of 13813 to John Barnes.
Status: CLOSED. Copy was provided by editor, Don Sando.
(UK): Make a recommendation regarding the changes necessary for 13813.
Status: CLOSED. Report is included in N383.
[See Report of Editor, 13813]
(ARG Chair): Upon receipt of the UK recommendation, consider the packaging appropriate for the functionality of the current 13813.
Status: OPEN. Not yet timely.
ISO/IEC JTC1/SC22/WG9 recommends to SC22 that the following standard be withdrawn when it reaches the end of its five-year life. The standard is relevant to the 1987 version of the Ada language standard rather than the current version:
Status: CLOSED. This resolution was reported to SC22 and endorsed (Resolution 99-19) at their plenary meeting in September 1999. JTC1 voted in March 2001 to approve withdrawal. Routine processing by ITTF has implemented the withdrawal according to ISO/IEC JTC 1/SC22 N3294, 2001-08-27.
ISO/IEC JTC1/SC22/WG9 recommends to SC22 that the following Technical Report be withdrawn when it reaches the end of its five-year review period. The Technical Report is relevant to the 1987 version of the Ada language standard rather than the current version:
Status: OPEN. This resolution has been reported to SC22 and endorsed (Resolution 00-22) at their plenary meeting in September 2000. JTC1 will ballot the withdrawal in early 2002. Implementation of the resolution can be expected before the end of 2002.
ISO/IEC JTC1/SC22/WG9 recommends to SC22 that the following Standard be confirmed when it reaches the end of its five-year review period:
ISO/IEC JTC1/SC22/WG9 recommends to SC22 that the following Standard be withdrawn when it reaches the end of its five-year review period:
Status: OPEN. SC22 endorsed these recommendations at its September 2001 plenary meeting. JTC1 will ballot the recommendation during 2003. Implementation of the withdrawal of 13814 can be expected before the end of 2004.
WG9 endorses the following New Work Item Proposal [see N388] for amendments to the Ada Language Standard and forwards it to SC22 for approval:
Status: OPEN. The request was forwarded to SC22 as a request for subdivision of the existing project for ISO/IEC 8652. The subdivision was reported approved by SC22 in their document N3310. The request has been forwarded to JTC1 for routine approval.
ISO/IEC JTC1/SC22/WG9 requests that SC22 request JTC1 and any other appropriate bodies to take action to ensure that ISO/IEC TR 15942 be made freely available on a web site.
Status: OPEN. The request [See N390] was forwarded to SC22 for endorsement. SC22 has scheduled a letter ballot for endorsement of the request. The request would then be forwarded to JTC1 for endorsement and ultimately to ISO Central Secretariat for implementation.
[Agenda]
[Agenda]
Project 22.35 -- (Type 2) TR 11735:1996 EXTensions for real-time Ada, Nasser Kettani, Editor
The contents of 11735 are substantively subsumed by the 1995 revision of 8652. This Technical Report will be withdrawn when usage of the 1987 version of the Ada language has diminished.
ISO/IEC JTC1/SC22/WG9 recommends to SC22 that the following Technical Report be withdrawn when it reaches the end of its five-year review period. The Technical Report is relevant to the 1987 version of the Ada language standard rather than the current version:
Status: OPEN. This resolution has been reported to SC22 and endorsed (Resolution 00-22) at their plenary meeting in September 2000. JTC1 will ballot the withdrawal in early 2002. Implementation of the resolution can be expected before the end of 2002.
[Agenda]
Project 22.31 -- IS 12227:1995 SQL/Ada Module Description Language (SAMeDL), Andreas Koeller, editor.
ISO/IEC JTC1/SC22/WG9 recommends to SC22 that the following standard be withdrawn when it reaches the end of its five-year life. The standard is relevant to the 1987 version of the Ada language standard rather than the current version:
Please be advised that ISO/IEC 12227 has been officially withdrawn and is no longer on the SC 22 programme of work.
[Agenda]
Project 22.10.04 -- IS 13813:1998 Generic packages of real and complex type declarations and basic operations for Ada (including vector and matrix types), Don Sando and Ken Dritz, editors
Project 22.10.05 -- IS 13814:1998 Generic package of complex elementary functions for Ada, Jon Squire and Ken Dritz, editors
As you know, every standard is reviewed at five years of age to determine if it should be confirmed (kept as is), revised, or withdrawn. This year we begin the five-year review of the following WG9 standards:
13813 and 13814 are, of course, for Ada 83. I dug drafts of them, eight years old, out of my files; I don't think I ever saw the finished standards. I shall presume that my drafts reflect what was in the final standards.
13813 defines a generic complex types package, an array exceptions package, a generic real arrays package, and a generic complex arrays package. Of these, only the first is contained in Ada 95. As I recall, the reason for that was that we didn't want to standardize array subprograms "prematurely"; we wanted to wait until such future time as syntax and semantics for generalized array "sections" (multidimensional slices) could be defined in the core language. The generic complex types package in Ada 95 is functionally comparable to the one in 13813, but not identical.
13814 defines a generic complex elementary functions package. The generic complex elementary functions package in Ada 95 is functionally comparable to the one in 13814, but not identical. The biggest difference is that the latter separately imports a long list of complex operations as generic formal subprograms with box defaults (normally expected to be defined by an instantiation of the generic complex types packages at the place where the generic complex elementary functions package is instantiated), whereas the former imports just an instantiation of the generic complex types package.
Given that 13813 provides considerably more functionality than does the only part of it that was incorporated into Ada 95, it might be reasonable to reaffirm that standard. However, I believe there is a technical problem in doing so. The generic complex types package defined in 13813 renames an exception defined by the generic elementary functions package in 11430, which has been withdrawn. The generic complex elementary functions package also renames that exception.
At the suggestion of Barnes, we separate the discussion of the two standards. There is consensus that 13814 should be withdrawn. Discussion continues on the future of 13813. Michell asks if WG9 currently has the expertise needed to revise 13813 because the needed changes might not be simple. Tokar suggests that we might leave the standard in place for now and ask the ARG to include the functionality in the planned amendment to 8652. No one knows of any vendor implementations of the standard but Barnes says that implementation by users is straightforward.
We break for coffee. Following the break, the convener suggests the following plan:
There is general agreement with this approach.
ISO/IEC JTC1/SC22/WG9 recommends to SC22 that the following Standard be confirmed when it reaches the end of its five-year review period:
ISO/IEC JTC1/SC22/WG9 recommends to SC22 that the following Standard be withdrawn when it reaches the end of its five-year review period:
JTC 1/SC22 recommends to JTC 1 that at the end of their 5-year review period:
(Convener): Send electronic copy of 13813 to John Barnes.
Status: CLOSED. Copy was provided by editor, Don Sando.
(UK): Make a recommendation regarding the changes necessary for 13813.
Status: CLOSED. Report is included in N393.
(ARG Chair): Upon receipt of the UK recommendation, consider the packaging appropriate for the functionality of the current 13813.
Status: OPEN. Not yet timely.
[See Recommendation on ISO/IEC 13813 from the UK]
ISO/IEC 8652:1995 Information Technology--Programming Languages--Ada
ISO/IEC 8652:1995/COR.1:2000 Technical Corrigendum
Project 22.10.01, Randy Brukardt and Erhard Ploedereder, Project Editors
ISO/IEC 18009:1999, Ada Conformity Assessment, Erhard Ploedereder
Project 22.18009, Erhard Ploedereder, Project Editor
(Convener): Contact Prof. Alfred Strohmeier to determine if Springer-Verlag can publish the ARM.
Status: CLOSED. Prof. Strohmeier has reached an understanding with Springer to publish the ARM as part of the lecture notes series in November. Ada-Europe will probably distribute copies to its members. Implementing Resolution 40-5, the US sent a copy of the manuscript of the consolidated ARM to Prof. Strohmeier for transmission to Springer.
WG9 endorses the following New Work Item Proposal [see N388] for amendments to the Ada Language Standard and forwards it to SC22 for approval:
Summary of Voting on SC 22 N 3241, Request for Project Subdivision of ISO/IEC 8652 - Ada
DATE ASSIGNED: 2001-09-12
STATUS: Per the results of this ballot, the project subdivision request is approved. It will be forwarded to JTC 1 for final approval along with any other programme of work changes that are approved at the SC 22 Plenary.
The ARG met in Leuven in May. About 1/3rd of the meeting was spend on "normal" AIs, i.e. corrections to problems in the existing RM. 2/3rds of the meeting was spent on amendment AIs. It becomes evident that at this stage integrating new features in the language in a way that is both compatible with existing code, and not too disruptive to implementations, is extremely challenging. Other than the Editor of the project, there is no funding for this language design effort. This means that the work that is needed for the amendment is done on a voluntary basis, and in practice that relatively little progress takes place between meetings. The Rapporteur feels that relatively few amendments AIs will be mature enough in 2005 for inclusion in the official Amendment document. Note that the situation is different for AIs that have to do with normal maintenance of the language, because in these cases it is much easier to understand the problem at hand and the impact of proposed solutions.
The procedures of the ARG are being revised to (1) deal with the fact that we are now going to work on extensions to the language, (2) put them in accordance with the rule of the parent bodies and (3) reflect existing practice. The revised procedures have been drafted by the Editor and Rapporteur of the ARG, and submitted to the convener of WG 9 for review. They are expected to be approved by the ARG at its next meeting, and will be presented at the next meeting of WG 9.
One of the significant changes of the new procedures has to do with the disposition of comments submitted to the ada-comment mailing list. Because the ARG is soliciting input from the Ada community regarding possible amendments to the language, a sizeable number of suggestions have been received by email. Previously, each email received on ada-comment would result in an AI. But the ARG felt that if the same rule were applied to suggestions for amendments, there would be a danger of spending precious ARG time on proposals that are not well thought-out or would have an unacceptable impact on the Ada community. Therefore, the Editor and the Rapporteur are in charge of doing an initial triage of the comments, only creating AIs for those that seem to deserve detailed consideration by the ARG. A new category of document, ACs (for Ada Commentaries) is created to record the suggestions and any discussion pertaining to them. ARG members may request that ACs be turned into AIs if they think a suggestion has some value.
The ARG has its "usual" motion for the October meeting for approval of a series of AIs. A pointer to retrieve AIs is included.
The cited AIs can be retrieved from the ACAA web site for AIs.
(Most of these AIs are still in editorial review by the ARG, which will end in September. Any AIs needing major repairs after this review will, as always, be deleted from the motion at the meeting. Editorial comments by WG9 are very welcome and are to be sent to [email protected].)
A manuscript of the consolidated ARM has been submitted to Springer-Verlag via Alfred Strohmeier for hardcopy publication.
[Agenda]
ISO/IEC 15291:1999, Information Technology--Programming Languages--Ada Semantic Interface Specification (ASIS)
Project 22.15291, Clyde Roby and Steve Blake, editors
A report on the recent meeting of the ASIS RG is included in the Appendix.
[Agenda]
ISO/IEC TR 15942:2000, Guidance for the use of the Ada Programming Language in High Integrity Systems
Project 22.15942 Brian Wichmann, Editor
The recent meeting of the HRG confirmed that they wish to move ahead on drafting a Technical Report providing advice on the usage of the Ravenscar profile. They developed a list of contents and assigned an author to each section. They plan to develop a first draft within six months. They plan to bring an NP to the WG9 meeting following completion of the initial draft.
The HRG also discussed the continuing role of Annex H of ISO/IEC 8652. They discussed the desirability of changing its title to High-Integrity rather than Safety and Security. The HRG might recommend that the fourth section of Annex H should be reworked to better fit with the recently completed TR 15942. They also considered tracking the usage of relevant pragmas implemented by various vendors.
It is understood that the HRG may work with the University of York or other institutions in obtaining material that might be incorporated into a Technical Report.
ISO/IEC JTC1/SC22/WG9 requests that SC22 request JTC1 and any other appropriate bodies to take action to ensure that ISO/IEC TR 15942 be made freely available on a web site.
JTC 1/SC22 instructs its Secretariat to issue a letter ballot on the following:
ISO/IEC JTC 1/SC22 endorses the request from WG9 in SC22 N3256 that ISO/IEC TR 15942, Guidance for Use of Ada In High Integrity Systems (Type 3 TR), be made freely available, and directs the SC22 Secretariat to immediately forward this request to ISO/IEC JTC 1 along with the rationale shown below.
Rationale: TR 15942 qualifies under the criteria provided by JTC 1 Sendai Resolution 32 because it is a Technical Report. It also qualifies under the criteria of JTC1 N 5165 because it explains inter-relationships among the referenced standards and thereby serves to promote the work of JTC1 possibly leading to increased sales of the referenced standards.
An initial draft of a Technical report has been produced, and lots of comments have come in which is good. We aim to meet (but not confirmed yet) on Thursday 4th Oct as part of SigAda. This meeting will produce a first real draft.
[Agenda]
[Agenda]
The time has come to decide whether to maintain ISO 14519:1999 (combining IEEE Std 1003.5, 1003.5b, 1003.5c), the standard for Ada bindings to POSIX. The "Austin Group" project is producing a combined ISO/IEEE/Open Group standard for POSIX and Unix. This new standard, whose balloting process is rapidly drawing to a close, will will include C bindings for a set of realtime extensions and modifications (from IEEE Stds 1003.1d, 1003.1i, and 1003.1j) that are not covered by IEEE Std 1003.5.
There is currently only one active IEEE project working on Ada language bindings, and they are not making very rapid progress. The one active group is the 1003.5g working group. This group is also a subcommittee of the SAE (Society of Automotive Engineers), AS-5B. This subcommittee is a group of people from the aerospace industry, who are interested in standardizing an API for avionics operating systems. They decided to base their work on the IEEE Std 1003.13, the real-time POSIX profiles. These profiles are specified in terms of both C and Ada language interfaces. The Ada profiles are subsets of IEEE Std 1003.5. The AS-5B group found that they needed functionality not present in ISO 14519:1999, and so requested authorization from the IEEE to extend the Ada interfaces in IEEE Std 1003.5. In particular, the group intended to extend the Ada API to include much of the real-time functionality that was added to the POSIX C-language bindings by IEEE Stds 1003.1d, 1003.1i, and 1003.1j. With these extensions to IEEE Std 1003.5, they then intended to define a set of new real-time profiles for avionics, extending IEEE Std 1003.13. Progress has been very slow, and apparently almost entirely due to the persistence of one person, Diane Schleicher. Based on the current trajectory, I don't see the project ever completing without a significant infusion of new human resources.
The slow progress of 1003.5g has brought us to a sort of crisis. Now that IEEE Std 1003.1 (C-language bindings) has been revised to include additional real-time extensions, the group responsible for maintaining IEEE Std 1003.13 (real-time C and Ada profiles) is preparing to revise that standard to bring it into synchronization with the new POSIX/Unix standard C-language API.
We are now coming under pressure from the 1003.13 revision project to update 1003.5, or else there will be features in the C-language real-time profiles that are not available for mapping to Ada bindings. It is time to make a decision. It seems pretty clear that continuing along the current course will mean that 1003.5 will not be successfully revised again, i.e., it will remain static, without bindings for the 1003.1d and 1003.1j realtime functions.
The only reason the current 1003.5 exists is that several people -- including, but not limited to, myself -- were funded to work on it. A large chunk of the funds came originally mostly through the Ada Joint Program Office, and more recently some came from the DISA Center for Standards. In total, this amounted to several hundred thousand dollars over a span of several years. For the past couple of years, since the completion of IEEE Std 1003.5c (Sockets and XTI) support for revisions of IEEE Std 1003.5 has apparently been limited to Diane Schleicher's project, and that has not been enough to get all the work done.
IEEE PASC is currently trying to decide what to do about the 1003.13 (realtime profiles) revision. The chair of that working group has presented two alternatives:
Either way, the Ada bindings will lag behind the C bindings in the real-time area until and unless a few people step up to do the work up updating them. If there are people and organizations who care enough about keeping the Ada bindings up in sync with the POSIX/Unix C-language API to fund one or two people to take an active role in revising 1003.5 to include the 1003.1d, 1003.1i, and 1003.1j functions, they should contact me or one of the other members of the PASC SEC.
[Agenda]
None is anticipated.
[Agenda]
[See N395]
[See N396]
[Agenda]
We appreciate the comfortable accommodations provided by SIGAda and the National Body of the US. The following resolution expresses WG9's gratitude.
We appreciate the services of the meeting Secretary. The following resolution expresses WG9's gratitude.
We appreciate the services of the WG9 Webmaster. The following resolution expresses WG9's gratitude.
The Technical Corrigendum to the Ada Reference Manual was published on 1 June 2001. The following resolution congratulates the editors.
According to the JTC1 Directives, Rapporteur Groups serve from meeting to meeting of the parent body. The following resolution continues the existing RGs and appoints their Chairs until the next meeting of WG9.
Upon the retirement of Professor Erhard Ploedereder as chair of the Ada Rapporteur Group, we appreciate his long years of service to WG9 and the Ada community.
[Agenda]
(The resolutions will be renumbered after the meeting.)
The minutes of Meeting #40 as contained in document N389 are approved.
[Discussion] [Agenda]
ISO/IEC JTC1/SC22/WG9 continues the following Rapporteur Groups until the next plenary meeting and expresses its grateful appreciation to their chairs for their continuing service:
[Discussion] [Agenda]
WG9 schedules future meetings as follows:
[Discussion] [Agenda]
WG9 adopts the recommendations contained in "Recommendation on ISO/IEC 13813 from the UK" as its plan for dealing with ISO/IEC 13813. Accordingly, the convener is directed to circulate an email ballot in WG9 for approval to revise ISO/IEC 13813 and to appropriately pursue the ballot results in SC22.
[Discussion] [Agenda]
WG9 approves following AIs as written by the ARG:
Amendment AIs:
AI95-00218/05 2001-05-18 -- Accidental overloading when overriding
Normal AIs:
AI95-00185/03 2001-05-20 -- Branch cuts of inverse trigonometric and hyperbolic functions
AI95-00221/02 2000-04-12 -- Default_Bit_Order is static
AI95-00223/02 2000-04-12 -- Line terminators are skipped by Get.
AI95-00227/04 2000-11-28 -- Behavior of Ada.Streams.Read when at the end of stream
AI95-00235/04 2000-11-28 -- Resolving 'Access.
AI95-00236/02 2000-11-19 -- Minimum criteria for metrics documentation
AI95-00237/04 2001-05-20 -- Finalization of task attributes
AI95-00241/02 2000-12-11 -- Testing for Null_Occurrence
AI95-00253/02 2001-05-20 -- The legality rules for pragmas Attach_Handler and Interrupt_Handler are similar
AI95-00258/02 2001-05-20 -- Behavior of Interfaces.C.To_C when the result is null
AI95-00268/02 2001-05-25 -- Rounding of real static expressions
[Discussion] [Agenda]
ISO/IEC JTC1/SC22/WG9 expresses its grateful appreciation to SIGAda and the National Body of the USA for their gracious accommodations in hosting Meeting #41.
[Discussion] [Agenda]
ISO/IEC JTC1/SC22/WG9 expresses its grateful appreciation to Clyde Roby for serving as Secretary of Meeting #41.
[Discussion] [Agenda]
ISO/IEC JTC1/SC22/WG9 expresses its grateful appreciation to Clyde Roby for maintaining the WG9 Web Page.
[Discussion] [Agenda]
Noting the recent publication of the Technical Corrigendum to ISO/IEC 8652, ISO/IEC JTC1/SC22/WG9 congratulates and thanks the Corrigendum editors, Randy Brukardt and Erhard Ploedereder.
[Discussion] [Agenda]
ISO/IEC JTC1/SC22/WG9 expresses its grateful appreciation to Professor Erhard Ploedereder for his many years of service to WG9 and the Ada community as Chairman of the Ada Rapporteur Group.
[Discussion] [Agenda]
Planned time for adjournment is 1:00 pm.
[Agenda]
The standard ISO/IEC 13813 entitled generic packages of real and complex type declarations and basic operations for Ada (including vector and matrix types) will soon be up for review. This note reviews the background to the development of the standard and makes a recommendation that the standard be revised.
The Numerics Working Group of WG9 met many times during the period when Ada 95 was being designed and produced a number of standards. They were faced with the problem of whether to produce standards based on Ada 83 (87 in ISO terms) or whether to base them on Ada 95 or subsume them into Ada 95. One dilemma was of course that although Ada 95 was on the way nevertheless Ada 83 was expected to continue in use for many years.
The standards are
11430 and 11729 are mentioned for completeness. They were published in 1994. They were based entirely on Ada 83 and their facilities are provided in the Ada 95 core language. The elementary functions, 11430, became the package Ada.Numerics.Generic_Elementary_Functions and the primitive functions, 11729, became the various attributes such as 'Floor and 'Ceiling, and 'Exponent and 'Fraction. These two standards were withdrawn recently and need no further mention.
The other two standards, 13813 and 13814, were published in 1998 and will soon be up for review at the end of their five year period. Three possible fates can befall a standard when it is reviewed. It can be withdrawn, revised or confirmed.
In the case of 13814, the functionality is all incorporated into the Numerics Annex of Ada 95 as the package Ada.Numerics.Generic_Complex_Elementary_Functions. There are a few changes in presentation because the Ada 95 package uses the generic package parameter feature which of course did not exist in Ada 83. Nevertheless there seems little point in continuing with 13814 and so at the Leuven meeting of WG9 it was agreed to recommend that it be withdrawn.
However, the situation regarding 13813 is not so clear. Some of its functionality is included in Ada 95 but quite a lot is not. The topics covered are (1) a complex types package including various complex arithmetic operations, (2) a real arrays package covering both vectors and matrices, (3) a complex arrays package covering both vectors and matrices, (4) a complex input-output package.
The complex types package (1) became the package Ada.Numerics.Generic_Complex_Types and the input-output package (4) became Ada.Text_IO.Complex_IO. However, the array packages, both real and complex, were not incorporated into the Ada 95 standard.
At the Leuven meeting, it was agreed that 13813 should not be withdrawn without further study. The UK was asked to study whether small or large changes are required in 13813 and to report back at the next meeting (Minneapolis in October 2001). The Ada Rapporteur Group would then decide whether the functionality should be included in a future revision or amendment to Ada 95.
This is an interim report from the UK.
It is recommended that 13813 be revised so that it only contains the functionality not included in Ada 95.
The revised standard should contain two generic packages namely Ada.Numerics.Generic_Real_Arrays and Ada.Numerics.Generic_Complex_Arrays.
There should also be standard non-generic packages corresponding to the predefined types such as Float in an analogous manner to the standard packages such as Ada.Numerics.Complex_Types and Ada.Numerics.Long_Complex_Types for Float and Long_Float respectively.
The text of the Ada specifications of the two generic packages should be exactly as given in the non-normative Annex G of the existing standard 13813. (This Annex illustrates how the existing standard packages might be rewritten using Ada 95.)
There is an important issue regarding what should happen if there is a mismatch in the array lengths of the parameters in a number of the subprograms provided by the packages. For example if
function "+" (Left, Right: Real_Vector) return Real_Vector
be called with parameters such that Left'Length /= Right'Length.
The existing standard raises the exception Array_Index_Error which is declared alone in a package Array_Exceptions. The nonnormative Annex G shows this exception incorporated into the package Ada.Numerics thereby producing an incompatibility with the existing definition of Ada.Numerics.
We considered four possibilities regarding this exception
We concluded that
We therefore recommend Option (3) that Constraint_Error be raised on mismatching of parameters.
If the Ada95 standard itself be revised at some later date then consideration should be given to incorporating the functionality of the revised 13813 into the Numerics Annex.
The proposed text of the revised standard is as shown below.
<<This is to be added>>
We acknowledge the valuable assistance of Donald Sando, the editor of the original standard, in the preparation of this recommendation.
[Discussion] [Agenda]
Those in attendance were: Dan Baysinger, Ann Brandon, Currie Colket, Steven Deller, David W. Glessner, Robert Leif, Clyde Roby, Jean-Pierre Rosen, and Paul Stachour.
The primary focus of the Ada Semantic Interface Specification (ASIS) Working Group (ASISWG) and ASIS Rapporteur Group (ASISRG) has been to evolve ASIS as an interface to the Ada 95 compilation environment. ASIS now provides a powerful mechanism to perform code analysis for mission-critical and safety-critical applications. A variety of highly effective tools have been built using ASIS. ASIS became an ISO standard in 1999.
This workshop was oriented towards brainstorming the processes to develop an ASIS standard to support an Ada 200X (perhaps Ada 2005?) standard. A group of nine enthusiastic participants held excellent discussions concerning several topics, including:
After an introduction by Currie Colket, chair of ASISWG/ASISRG, he explained to the group present that we needed to be thinking of the process of developing new interfaces for ASIS based upon the new features to be present in Ada 200X so that when that standard comes out, the appropriate ASIS standard will follow very soon thereafter.
Currie then went through his slide presentation:
Although the meeting was originally scheduled to be about an hour, the animated discussions that were part of the meeting lengthened it to about 2-1/2 hours. The next ASISWG/ASISRG meeting or workshop is expected to be held at Ada-Europe 2002.
[Discussion] [Agenda]
N363 Minutes and Resolutions of Meeting #36
N367 Minutes and Resolutions for Meeting #37 of ISO/IEC JTC1/SC22/WG9, Friday, 22 October 1999, Redondo Beach, California, USA
N372 Minutes and Resolutions for Meeting #38 of ISO/IEC JTC1/SC22/WG9, Friday, 30 June 2000, Potsdam, Germany
N378 Plenary Meeting Report of ISO/IEC JTC1/SC22, 11-15 September 2000, Nara, Japan
N385 Minutes and Resolutions for Meeting #39 of ISO/IEC JTC1/SC22/WG9, Friday, 17 November 2000, Laurel, Maryland, USA.
N388 Request for Subdivision of Project ISO/IEC 8652:1995
N389 Minutes, Meeting #40 of ISO/IEC JTC1/SC22/WG9, Friday, 18 May 2001, Leuven, Belgium
N390 Request to Make a Technical Report Freely Available on the Web
N391 Convener's Report, 2001
N392, Announcement, Meeting #41 of ISO/IEC JTC1/SC22/WG9, Friday, 5 October 2001, Bloomington, Minnesota, USA
N393, (this document)
N394, (superseded)
N395, Excerpts from Directives of ISO/IEC JTC1, Part 1, Related to Liaison Organizations
N396, Rules for JTC1 Workshop Mode of Operation
ISO Web Site: http://www.iso.ch/
JTC1 Web Site: http://www.jtc1.org/
SC22 Web Site: http://www.open-std.org/jtc1/sc22/
WG9 Web Site: http://www.open-std.org/jtc1/sc22/wg9/
ACAA Web Site: http://www.ada-auth.org/
ACAA Web Site for AIs: http://www.ada-auth.org/cgi-bin/cvsweb.cgi/AIs/
SIGAda 2001 Conference Web Site: http://www.acm.org/sigada/conf/sigada2001/
[Agenda]
End of Document