------------------------------------------------------- Minutes of meeting ISO/IEC JTC1 SC22 WG17 N249 ------------------------------------------------------- WG17 (Prolog) meeting, 24-25th August 2013, Istanbul, Turkey. Jonathan Hodgson ISO/IEC JTC1 SC22 WG17 (Prolog) Convener 0.1 Annexes A --- Resolutions. B --- Address list. 1. Attendance. Klaus Daessler(Germany), Jonathan Hodgson (Convener) , Ulrich Neumerkel (Austria), See Annex B for address list. The meeting began at 9:45 am August 24th 2013. 2. Agenda for meeting -- N247. The Agenda was approved unanimously. 3. Drafting committee and secretary WG17 decided that if a drafting committee were to be required for this meeting Jonathan Hodgson and Ulrich Neumerkel would serve on it. Jonathan Hodgson agreed to serve as secretary. 4. Minutes of the Budapest meeting. The minutes of the Budapest meeting (N 237) with minor adjustments were approved unanimously. 5. Convener's announcements. After a discusion it was decided that Ulrich Neumerkel will informally arrange a meeting in Vienna in July 2014. 6. Corrigenda a. There was a discusion of the format of error terms. It was noted that the presence of the implementation defined term can cause problems if an implementation assumes a specific form and thus does not allow "_" as the argument of 0 the implementation defined term. b. Ulrich Neumerkel noted that consideration of an implementation for normative purposes requires that the webpage of the implementation claim ISO compliance. c. Review of conformance The web page: "http://www.complang.tuwien.ac.at/ulrich/iso-prolog/conformity_assessment'' summarizes the current state of conformance of the implementations claiming ISO conformance. d. A resolution to draft an amendment to part 2 in the form of an abstract specification that allows a common subset of Sicstus, SWI and YAP to be standard conforming was agreed to. It was noted that operators are local in SWI but not Sicstus. e. The read- and write- options ``variable_names/1'' were discussed. It was noted that there is a vulnerability based on the use of $Var other than integers. There is a need to be able to write out terms with variable names. In particular the question of error handling must be clarified. 7. The Prolog prologue. Options for the proposed predicates were reviewed. a.member, b.append, c. length -- should infinite lists generate a resource error or a representation error? d. between, e. select, f. succ, g. map_list. 7. DCGs (WG 17 N244 and N245) The following were noted. a. Section 7.14 .5 shall begin with a statement to the effect that for each control construct formal definition reference to the reference implementation shall be by the principal functor of the first argument. b. 7.14.5 shall be removed. Parts may be placed in 7.15.7. c. Ordering of subclauses on control constructs shall parallel that in the reference implementation. d. Per Milner's comment on functor is to be rejected. e. The definitions -- clause 3 -- were reviewed. The word ``semicontext'' was accepted in lieu of the current ``right hand context''. f. Per Mildner's remark on the steadfastness of phrase was rejected. 8. Next meeting. The next meeting will be in Vienna in conjunction around the time of FLOC 2014 9. The meeting adjourned at 1.00 pm. August 25th. A. Resolutions. A 1. There shall be a draft amendment to 13211-2 Modules to allow a common subset of Sicstus, YAP, and SWI Prolog implementations to be conforming. Jonathan Hodgson will prepare this by November 1st 2013. Individuals: Unanimous. Countries: Unanimous. A 2. There shall be further discussion of any additional errors to write_term for the cases where the write-option variable_names is present. A corrigendum choosing between no errors and detailed errors shall be prepared by Ulrich Neumerkel once he finds agreement amongst implementations. Individuals: Unanimous. Countries: Unanimous. A 3. Clauses of the reference implementation shall be referred to via the principal functor of the first augment of the clause. The order of the subclauses shall mirror the order in the TR. Ulrich Neumerkel will modify the reference implementation by September 30th 2013 to account for the new ordering. Individuals: Unanimous. Countries: Unanimous. A 4. Klaus Daessler shall produce a new version of the TR by Nov. 15th 2013. Intermediate and revised versions to be available in source code as well as pdf. Individuals: Unanimous. Countries: Unanimous. A 5. WG17 thanks the organizers of ICLP 2013 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 Jonathan Hodgson Dept. of Computer Science St. Joseph's University 5600 City Avenue Philadelphia. PA 19131 USA Tel: +1 610 328 6835 E-Mail: jhodgson@sju.edu Ulrich Neumerkel Institut für Computersprachen E185/1 Technische Universität Wien Argentinierstraße 8/4 A-1040Wien Austria ulrich@complang.tuwien.ac.at