------------------------------------------------------- Minutes of meeting ISO/IEC JTC1 SC22 WG17 N207 ------------------------------------------------------- WG17 (Prolog) meeting, 10th December 2008. Udine Italy. Jonathan Hodgson ISO/IEC JTC1 SC22 WG17 (Prolog) Convener 0.1 Annexes A --- Resolutions. B --- Address list. 1. Attendance. Klaus Daessler(Germany) , Bart Demoen (Belgium), Jonathan Hodgson (Chair),Paulo Moura (Portugal) , Katsuhiko Nakamura (Japan) , Ulrich Neumerkel (Austria), Roger Scowen (UK) , Peter Szeredi (Hungary), Markus Triska (Austria), Jan Wielemaker (Holland). See Annex B for address list. 2 Agenda for meeting -- N205 3 Drafting committee and secretary WG17 decided that a drafting committee was not required for this meeting. Jonathan Hodgson agreed to serve as secretary. 4 Minutes of the Oporto meeting (WG17 N199) The minutes of the Oporto meeting were approved. 5. Convener's Remarks Jonathan Hodgson indicated that he hopes that at this meeting we can a. finalize the DCGs document so that it can be balloted, and b. devise a method to proceed to a ballot on the Globals proposal. 6. Progress report on the Technical report on DCGs. It was agreed that: a.Error handling on phrase is to be optional. The example phrase({X=a}, X,X) shows how complex error handling could be when the items being processed are lists. b. It was agreed that the behavior of DCG expansions that led to conflict with a Built in predicate the behaviour should be implementation defined. a non terminal call/1 should expand to a call of call/3. c. It was resolved (resolutions A 1) that the DCGs document shall be an independent stand alone document. d. It was further resolved (resolution A2) that Paulo moura be asked to prepare a final draft of the DCGs proposal taking into account the discussion at the meeting. 7. Discussion of the Japanese Proposal on Globals and Arrays. Katsuhiko Nakamura introduced the wew draft. This draft was edited following the style used for the DCGs document. Paulo Moura supplied the style document and Jonathan Hodgson assisted with the English. There was dicussion on the issue of whether globals can be any ground terms. The names for access and modification will be changed to set_global_value/2 and global_value/2. A predicate current_global_value/2 which fails if there is no such global shall be provided by analogy with current_prolog_flag/2. It was pointed out that the behavior of copy_term needs to be specified along with the meaning of ``ground'' for a global. It was resolved (resolution A 3) to ask Japan to produce a new draft on globals. It was also reolved (resolution A ) to ask Jan Wielemaker to produce a document on the use of mutables for arrays. 8. Threads. Paulo Moura reported that Progress is continuing. Three almost conformant implementations exist. 9. Corrigenda. Action item for Roger to review outstanding corrigenda. Action for Ulrich Neumerkel and Jan Wielemaker to address the status of call_cleanup. 10. Next meeting. Pasadena July 2009. 11. The meeting adjourned at 5.48 p.m. A. Resolutions. A. 1. The DCGs document shall be an optional extension to Part one in a separate document. Individuals. Unanimous Countries. Unanimous A 2. Paulo Moura to rewrite the DCG draft following the agreements 1 - 5 . 1. No type checking in phrase. phrase(+callable_term, ?term, ?term). 2. phrase is the only safe way to use grammar rules. 3. Expansion conflict implementation dependent. 4. Account will be taken of call//1 which expands to call/3 5. Change pred_property and current_pred to accept non terminal indicators. and other directives as required. Due Date: June 1st 2009 Individuals: Unanimous. Countries: Unanimous. A 3. Katsuhiko Nakamura to rewrite draft on globals to take into account the discussion. (Renames, and removal of assign_unique). set_global_value/2 and global_value/2, current_global_value/2 is to fail if there is no such variable. Due Date June 1st Individuals: Unanimous. Countries: Unanimous. A 4. Action Item for Ulrich and Jan to write a justification for a call_clean_p/2, and setup_and_call_cleanup/3 and to provide a draft specification for these predicates. Due Date June 1st Individuals: Unanimous. Countries: Unanimous. A. 5 Mutables and Arrays. Jan Wielemaker will prepare a document on using mutables to define arrays. Individuals: Unanimous. Countries: Unanimous. A6 . WG17 thanks the organizers of ICLP 2008 for their help in arranging this meeting. Individuals: Unanimous. Countries: Unanimous. B. Address List. Klaus Daessler Gesellschaft fur Mathematische Intelligenz Goethestrasse 34 D-01445 Radebeul Germany Tel: +49 351 8365590 E-mail: klaus.daessler@mathint.com Bart Demoen Dept. of Computer Science K.U. Leuven, 3001 Leuven, Belgium E-mail bmd@cs.kuleuven.be Jonathan Hodgson Dept. of Math/CSC St. Joseph's University 5600 City Avenue Philadelphia. PA 19131 USA Tel: +1 610 660 1571 Fax: +1 215 473 0001 E-Mail: jhodgson@sju.edu Paulo Moura University of Beira Interior 6200 Covilha Portugal. E-mail: pmoura@di.ubi.pt Professor K Nakamura Faculty of Science and Engineering Tokyo Denki University Hatoyama-machi Saitama-Ken 350-0394 JAPAN Tel: +81 492 96 2911 Fax: +81 492 96 6185 E-Mail: nakamura@k.dendai.ac.jp Ulrich Neumerkel Institut für Computersprachen E185/1 Technische Universität Wien Argentinierstraße 8/4 A-1040Wien Austria ulrich@complang.tuwien.ac.at Roger Scowen, 9 Birchwood Grove, Hampton, Middlesex United Kingdom TW12 3DU Tel: +44 (0)20 8979 7429; E-mail: (1) roger.scowen@npl.co.uk (2) patscowen@waitrose.com Peter Szeredi Dept. of Computer Science and Information Theory Budapest University of Technology and Economics H-1111 Budapest, Muegyetem RKP. 3-9 Hungary www.bme.hu szeredi@cs.bme.hu Markus Triska Institut für Computersprachen E185/1 Technische Universität Wien Argentinierstraße 8/4 A-1040Wien Austria triska@logic.at Jan Wielemaker, HCS, Univ v Amsterdam, Kruislaan 41G Amsterdam The Netherlands E-mail: wielemak@science.uva.nl j.wielemaker.uva.nl