VECTOR Vol.23 N°4 Table of Contents Ch-ch-changes Stephen Taylor ........................................................... 1 NEWS Quick reference diary ................................................................... 5 Changes at the BAA Paul Grosvenor .................................................. 6 Extraordinary General Meeting of the BAA Anthony Camacho ................ 9 Regulations of the British APL Association Anthony Camacho ............... 10 Annual General Meeting of the BAA Anthony Camacho ....................... 16 BAA Management Committee Meeting Anthony Camacho ................... 16 Industry news Sustaining Members .................................................. 17 DISCOVER Fire from heaven Adrian Smith ........................................................ 29 First experiences with Unicode in Dyalog 12 Adrian Smith ................... 41 Parallel Each David Liebtag ............................................................. 51 Classes as a tool of thought Simon Marsden ....................................... 57 An autobiographical essay Kenneth E. Iverson .................................... 70 LEARN SALT II Dan Baronet ...................................................................... 87 Functional calculation Neville Holmes ............................................... 96 The ruler’s edge revisited Ray Polivka ............................................. 103 If you think J is complex try j Norman Thomson ................................. 106 PROFIT Partitions of numbers R.E. Boss ..................................................... 121 About polynomials Gianluigi Quario .............................................. 132 Subscribing to Vector ................................................................. 142 i VECTOR Vol.23 N°4 ii VECTOR Vol.23 N°4 Ch-ch-changes Stephen Taylor [email protected] This is the first issue of Vector to appear without the BCS logo. Following an almost unanimous vote by our members we have ended our twenty-year affiliation to the British Computer Society. In his article “Changes at the BAA”, Paul Grosvenor discusses the reasons for this change, and what it now makes possible. The cover bears our new logo and we have taken this opportunity to refresh the design. There are changes inside the covers as well. With generous support from Dyalog (whose silver-anniversary history appears as a separately-bound supple- ment to this issue) we have upgraded our production process. Since 1987, Vector has been produced using Microsoft Word, thanks in very large measure to the skill of Adrian Smith in handling difficult font-mapping and typographical issues. The arrival of Unicode, and Adrian’s own work on the APL385 Unicode font, has allowed us in the last few years to present APL code on the Web far more simply. That in turn has allowed us to import HTML documents straight into Word, hugely reducing our typesetting work. This issue of Vector takes the next step: the markup has been changed from HTML to DocBook, an XML-based system widely used in technical publishing. This is the first issue to be produced without Word, and brings our production process into the publishing mainstream. Even without the character mappings of various APL implementations, typesetting Vector is demanding. Mathematical typesetting is a specialised skill. Where more verbose programming languages generally have their source code set as separate blocks, terse APL and J expressions appear ‘in-line’ all through our articles, reflect- ing the role Iverson intended for the ‘tool of thought’, but demanding the greatest care and attention in setting and proofing. (Is that comma part of an expression, or does it punctuate the English sentence?) Even had BAA been able to afford them, it is highly unlikely we could have produced Vector with professional type- setters. BAA owes Adrian Smith an unpayable debt of gratitude for keeping Vector in production for over two decades until the technology caught up. Appropriately enough, Adrian describes in this issue his first encounters with Dyalog’s new support for Unicode. APL publishing has become more active outside our pages too. This issue reviews Jeffry Borror’s new textbook q for Mortals. Graeme Robertson has published two APL textbooks, Dyalog has a new textbook in preparation from Bernard Legrand, 1 VECTOR Vol.23 N°4 and At Play With J is now being proofed, the first title to appear under the Vector Books imprint. Array languages are receiving renewed attention with the expiry of Moore’s Law. Unable to push clock speeds higher, computer manufacturers push more processors into their boxes. But sharing work between them is hard, and this has revved in- terest in functional- and array-programming languages. Microsoft has established a research centre around the F# group at Cambridge. Web 2.0 networking site LinkedIn.com now boasts a functional-programming group with over 300 members; the Iversonians group there has itself grown to nearly 90. In this issue David Liebtag reports how APL2’s new parallel-each operators tackle load sharing, and Neville Holmes continues his tutorial series on functional calcu- lation. R.E. Boss discusses how to partition numbers quickly. Much in this issue on the ‘tool of thought’ theme. Simon Marsden thinks his way through a problem using classes. His moves will surprise OO programmers unfa- miliar with interpreters, as much as it will APLers unfamiliar with classes. Gianluigi Quario finds new ways to write and think about polynomials, and Norman Thomson works through handling complex numbers in J. Celebrated educator Ray Polivka makes a welcome debut in Vector with this issue’s “In Session” column, returning to the derived and direct ‘ruler’s edge’ functions in Vector 23:1&2 and taking them back to traditional forms. Dan Baronet reports in “SALT II” on extensions to Dyalog’s code-management tools. Finally, we are pleased to publish an autobiographical essay by Ken Iverson. This has been extracted from the manuscript of The Story of APL & J, that he and Donald McIntyre were collaborating on up to his death. In our next issue we’ll have reports and papers from the Dyalog and APL2000 conferences this autumn: see the conference programmes in “Industry news”. 2 VECTOR Vol.23 N°4 NEWS VECTOR Vol.23 N°4 VECTOR Vol.23 N°4 Quick reference diary Meetings 12-15 Oct Elsinore, Denmark Dyalog 2008 Conference 10-11 Nov Bethesda, MD APL2000 User Conference Future issues of Vector Vol.24 Vol.24 Vol.24 N°1 N°2 N°3 Copy date 21 Oct 21 Jan 21 Apr Distribution December 2008 March 2008 June 2008 Back numbers Back numbers of Vector are available from: British APL Association c/o Gill Smith Brook House, Gilling East York YO62 4JJ Price per complete volume (4 issues) including postage: • £10 in UK • £12 overseas • £16 by airmail NB: Vol.1 N°2 is out of stock. 5 VECTOR Vol.23 N°4 Changes at the BAA Paul Grosvenor, British APL Association [email protected] A little bit of history Toward the end of 2007 and the start of 2008, the British Computer Society an- nounced changes to the way in which it manages and runs its Specialist Groups, which included, of course, the BAA. These changes were wide-ranging and had various knock-on effects. Perhaps the most obvious and controversial change was the requirement for all SG members to be members of the BCS. In the particular case of the BAA, where many of our members are retired from mainstream work or are based abroad, BCS membership would offer few advant- ages for them and additional expense; even though the first year’s membership would be free. More fundamental however were growing demands from the BCS of the BAA organisational committee, which prevented us from running our organisation in the way we wanted on behalf of the APL community. The restrictions placed upon us were seen to be increasingly obtrusive, right down to how we print Vector and to whom we may distribute it. After much heartfelt discussion, we held a ballot of the members on a resolution to end our affiliation to the BCS. We announced at our EGM on 19 June that this resolution had been passed. The voting was 184 in favour and 1 against. To get so many APLers all agreeing with each other is a rare event indeed and only goes to show the depth of feeling and importance of the issues under debate. There remains one outstanding issue regarding the BCS: our funds, which remain behind closed doors whilst we negotiate their return to us. There are all sorts of legal issues surrounding the ‘ownership’ of the funds which I shall not detail here other than to say that we consider the funds to be ours and that we will fight vig- orously to recover them. Until this issue is resolved we aim to run the BAA with a starting bank balance of zero. With the continuing, and generous, support of our Sustaining Members we should have working capital very shortly. Now we are independent and responsible for our own destiny or demise. 6 VECTOR Vol.23 N°4 So, what happens now? Well, immediately the decision to de-affiliate was made we had to change our Regulations accordingly and as a result identified a number of additional areas which were now somewhat out of date. Richard Nabavi and Anthony Camacho have volunteered to investigate and report back with suggested updates. We have decided not to change too much, too quickly. We plan to move forward with care, keep existing initiatives in place where possible and build confidence from our membership in our abilities. Your committee remains largely unchanged from pre-BCS days but with the addition of Chris Hogan who will be auditing our accounts going forward. At the time of writing we had nearly completed the process of opening a new bank account for the BAA but unfortunately, due to the money-laundering laws in the UK, this takes a long time. Once this account is up and running we can start to collect fees again and have a financial base from which to work. I am sure Nicholas Small will be in touch soon! We continue to produce Vector as before and in fact plan to produce even more varied copy and output over the future months. Vector 23:4 is due to go to press by the end of September; just in time for the conference season.