Support for Fortran Standards Development

Report June 2008

Introduction
Since January 2003 the BCS Member Services Board has generously provided means for members of the Fortran Specialist Group to support the UK contribution to the development of ISO Fortran standards. Initially this was undertaken as a project under the Specialist Groups Development Fund; in the past two years funding has been provided as part of the normal Fortran Specialist Group annual allocation.

The initial case for support had the objective "To support a continued UK contribution to the development of the ISO Fortran standard, Fortran 2000, and to allow the project to be completed to schedule". With the completion of that standard in November 2004 (although three Technical Corrigenda have since been produced and some interpretation requests remain outstanding) subsequent applications have had the objective, in effect, "To allow significant UK influence on the direction to be taken by Fortran in the next five years". The initial case from 2002 is at www.fortran.bcs.org/2003/devrep03.htm and subsequent annual reports are in, or are linked from, www.fortran.bcs.org/2007/devrep07.php

Activity 2007-2008
There have been two ISO Fortran (WG5) meetings during the past financial year, in London in August 2007 and in Las Vegas in February 2008. The London meeting was held at the BCS offices in Southampton Street, kindly provided free of charge as part of the BCS 50^th anniversary celebrations. There were seven participants from the UK at the first meeting and six at the second, while the total attendances were 18 and 20 respectively.

Most detailed technical development work continues to be undertaken by INCITS committee J3. One member of the British group is an active member of J3 and is also editor for the revision project.

At the August meeting a paper from the British group (N1682 in the WG5 archive, see below) expressed concern that the schedule for the current revision was too optimistic given that Fortran 2003 compilers were not yet available. It proposed extending the schedule by two years and cutting some items from the language. This was partially successful: the schedule was extended by ten months and two features were deleted.

This still left the revised language considerably larger than had been originally intended. This was partly due to the excellent work of J3 which, given a large set of 'do if time allows' work items, had completed virtually all of them. The most contentious item was coarrays - an extension to Fortran to accommodate the SPMD model of parallel programming. Members of the UK group hold varying views as to the merits of having coarrays in the base Fortran language, reflecting similar differences amongst UK Fortran users. Some are keen to access coarrays as soon as possible whilst others are largely indifferent and a few are actively opposed.

The principal business of the February meeting was to review the content of the second Working Draft of the revised Fortran standard prior to its processing as a Committee Draft for public comment worldwide and many detailed clarifications and simplifications were approved. UK members again proposed removing the coarray feature from the base language and putting it into a technical report or into an optional part of the standard. This gained the support only of the Japanese delegation and so was defeated. The US proposed the inelegant compromise of putting part of the facility into the base language and part into a technical report; this was approved.

The public comment period is now open and runs to August 2008; the draft standard is document N1723, a 7.8Mb PDF file in the WG5 archive. Members of the Fortran Specialist Group and all on other UK Fortran mailing lists have been invited to comment. The November 2008 meeting of WG5 will consider the comments and if all goes to schedule the project is on course for publication of the revised standard in June 2010.

All Fortran development papers are open to scrutiny by all interested parties worldwide; minutes of the two WG5 meetings are in N1717 and N1715 respectively. WG5 documents are available via its website www.nag.co.uk/sc22wg5/. J3 papers are obtainable from www.j3-fortran.org/.

The Group is extremely grateful for the continuing support of the BCS.

David Muxworthy
BSI Fortran Convenor
3^rd June 2008

Comments on this or any other of the Group's pages should be sent by e-mail to the FSG Web Editor.