Goodbye

At the end of May 2019 I am leaving Dyalog, so it seems like a good time to reflect on my time here and what I’ve learned from APL and the APL community.

When I joined Dyalog in 2010 I knew nothing about APL, so there was a really steep learning curve as I got to grips with both the language and its implementation. I was using some of my previous experience with compilers to improve the performance of the implementation, and thinking about ways to compile APL. This is a tough problem, and one that many people have worked on over the years (see for example Timothy Budd’s 1988 book An APL Compiler). My own ideas have shifted as I’ve gained more experience with APL and the way it is used. At first I thought “writing a compiler” was an obvious thing to do; now I think that hybrid compiler/interpreter techniques are much more promising, and Dyalog’s recent experiments with deferred execution and thunks are a good step in that direction.

At the same time, there was a lot of excitement around the APL language itself. Dyalog was working on APL#, a new .NET-based APL dialect (sadly abandoned as Microsoft’s own commitment to .NET waned). And Dyalog APL itself was starting to borrow more language features from the SharpAPL/J branch of the family tree, starting with the Rank operator and continuing over many years. This prompted me to delve more into the history of APL, to try to understand some of the fundamental differences between different implementations, so that we could reconcile those differences in Dyalog APL and provide, as far as possible, the best of both worlds. I think we’ve done pretty well in that, as evidenced by the fact that many APLers are happily using Rank, Key, function trains et al in an APL2-based language, something that seemed unthinkable a decade ago.

One of the most gratifying developments in the time I’ve been working with APL is the rapid growth of new APL implementations, open source projects and grass-roots enthusiasm. In particular, the open source movement has made it much easier for anyone with a good idea about language design to implement it, and share it with the world. We’ve seen a wide variety of new APLs and APL-inspired languages popping up over the years, ranging from full-featured to highly experimental, including but not limited to (in roughly the order I remember hearing about them): ELI, ngn/apl, GNU APL, Ivy, Aprildzaima/APL and APL\iv.

And speaking of new APLs, of course there is Co-dfns, a compiled APL implementation that tries to solve another tough problem: harnessing the power of GPUs and other massively parallel hardware in a way that makes it accessible to the end user. This is something that many people are trying to do, in a wide variety of languages, but as far as I can tell no-one has quite succeeded yet. The state of the art is still that, in order to get good performance, you need quite a lot of mechanical sympathy for the underlying hardware. But Co-dfns has come a long way, and if any language is well-suited to run on parallel array processors then surely it is APL!

This brings me on neatly to my next job: I’ll be working on compilers for GPUs, the parallel computers that render 3D graphics. They are closely related to their “general purpose” cousins the GPGPUs, which are used for pure number crunching, and to so-called tensor processing units (TPUs) that simulate neural networks for use in machine learning and artificial intelligence. “Tensor” here just means an array of arbitrary rank, or as we would say: an array. For programming TPUs there is a Python-based framework called TensorFlow. But, look closely at the APIs for some of the core TensorFlow libraries, and you’ll see operations like reshape, reverse and transpose, which are eerily similar to their APL equivalents. There truly is nothing new under the sun!

With fond regards to all APLers,
Jay.

Pool Stories: Fergus back on Form

It has been almost 2 years since our last post about Jo Fergus (daughter of our Customer Account Manager, Karen Shaw) the pool player who Dyalog have sponsored in the past. When we last updated you, Jo had just had her daughter, Remy, and made the difficult decision to take some time out from pool to concentrate on her new family.

On June 30th 2018 she married Tom Fergus, Remy’s Dad, in a small ceremony at Trowbridge County Hall and became Jo Fergus. The wedding came as a bit of a surprise to friends and family who thought they were attending a birthday lunch but the sun shone and a fantastic day was had by all. Jo started to miss playing pool and in 2018 she went to the Wiltshire county pool trials and was invited back into the Wiltshire Ladies A county team. After a successful season, in which they didn’t lose a match, the team has qualified for National County Finals taking place at the beginning of March. Jo has also joined a team playing in her local pool league.

In 2019 Jo took the decision to test herself and her pool skills and signed up to the 2019 IPA Ladies Tour which will see her play at 5 events across the UK. There are only 32 places on this Ladies tour and it will give Jo a chance to play against high level opposition, which she feels will improve her game. Ranking points will be awarded and the top 8 in the rankings after Tour 5 will automatically qualify for the first ever IPA Ladies Blackball Premier League.

Dyalog are proud to be sponsoring Jo for this tour and it is planned that all Ladies finals will be live streamed on freesports.tv so we have our fingers crossed she makes at least one final!

New York Dyalog Meetup

I am very pleased to announce the creation of the New York Dyalog APL Meetup group, details of which can be found online at https://www.meetup.com/New-York-Dyalog-APL-Meetup/. The meetup has been created and is organised by Paul Mansour, who is also sponsoring the venue for the inaugural meetup, scheduled for 6-9pm on Thursday February 7th, at Alley, 119 West 24th Street, New York. If you are interested in meeting APL users in the New York area, please join the Meetup group so that you will be notified of future events. Please sign up for events that you intend to attend so we know you are coming!

Meetup is a service used to organize online groups that host in-person events for people with similar interests, including programming languages. In addition to the New York group, there is also an APL Meetup group in Frankfurt which meets regularly. We welcome the creation of more local meetups! If you create one in your area, remember to inform us at Dyalog so that we can add a link from our event calendar, and arrange to stop by and speak when we are in your neighborhood!

The program for the meetup on February 7th is as follows:

6:00-6:30pm: Time for Networking

6:30-8:00: Morten Kromberg: New Ways of Working with APL

When you are busy solving problems, new technology can be an unwelcome distraction – but every now and again technologies appear which have the potential to make development, maintenance or distribution significantly easier. Morten will demonstrate some of the new ways of working with APL that have become available in the last few years, and also discuss likely features in the next couple of releases of Dyalog APL: 17.1 in Q2 of 2019 and 18.0 in 2020.

8:00-8:15 Short Break

8:15-9:00 Paul Mansour: Keeping it Simple – A Git Workflow for APLers.

Abstract: Git is great, but the newcomer can easily drown in a sea of commands and options. Git doesn’t tell you when or why to branch, when or why to merge or rebase, how to version your project or prepare a release. AcreFlow is a radically simplified Git workflow that answers these questions. It is implemented in Dyalog APL so you can branch, commit, and put out new versions directly from the APL session.

 

Phil Goacher (05-11-40 – 09-03-18)

Phil Goacher
I attended Phil Goacher’s funeral yesterday. He probably had no idea of just how much he would influence the development of APL. I first met Phil at W S Atkins which is a large UK engineering consultancy. There was a sub unit called Atkins Computing which provided internal computing support to the engineers and, crucially, provided a time sharing service to external users. He became my manager when I moved from supporting the transportation program suite to the brand new APL team.

Phil was more manager and business man than programmer but he had an engineering background in Gas distribution and thus the mathematical bias that seems common to APL users.

Phil was the sort of man with an eye for a business opportunity and when a advert appeared from someone who wanted to set up an APL consultancy with a limited objective to provide resources to Rank Xerox (UK arm of Xerox Corp) he turned up along with half his team. Phil was a wheeler dealer type and had already talked to the recruiter, persuaded him that he could manage the team, and then interviewed the candidates. So I wound up being interviewed by my existing manager. Following this Phil decided we only needed a salesman and we could set the consultancy up with a much wider remit. Phil recruited Ted Hare who was one of Atkin’s top salesmen and Dyadic Systems was born.

Phil did all of the necessary legal and administration to get Dyadic off the ground and became the company’s administration guy. He bought an Apple 2 with VisiCalc so was early into the spreadsheet concept. It must be said that all five of the people who started Dyadic were “early adopters” by nature.

Dyadic was quite successful as an APL consultancy but wanted to do more. I am not sure who instigated it (I was too busy consulting) but it was probably Phil’s idea to develop an APL of our own. Knowing Phil this was probably a business eye and a request from Pam Geisler who was Pauline Brand’s sister (Pauline was an early recruit that we “acquired” from Atkin’s) but, more importantly, high up in the management of Zilog. Zilog was developing a new 16 bit chip, Z8000, that was going to push them up market from the 8-bit chip with which they had had enormous success – Z80. IBM had been pushing APL as the future, and it was incumbent on competitors to provide an APL offering.

Phil and Dave Crossley will have been the instigators of recruiting John Scholes, who had also been at Atkin’s, and teaming him with me to develop Dyalog (Dyadic + Zilog). Dave provided the management overview of that project while Phil and Ted had to worry about financing John and I, who were not bringing in consultancy money. It was at this point that Dyalog APL became a UNIX and C project. It was much later when I read Dennis Ritchie’s obituary that I realised just how early we had got into UNIX and C.

Dyalog APL was not the instant success that Dyadic hoped for. It had increased costs. We needed an office and the paraphernalia that goes with selling a product rather than brains. Dyadic ran into financial issues and was taken over by Lynwood Scientific, who made terminals with Zilog Z8000 chips inside. I think they really wanted the Z8000 expertise that John and I had acquired. As part of that takeover Phil, Ted and Dave had to leave with a derisory pay-off and I lost touch until I learnt of his death a fortnight ago.

From the perspective of APL language development Phil is not a tower of strength. However, from the perspective of having provided the impetus and drive to get Dyalog APL developed, he is very important.

NOTE: For anyone interested in reading more about the early days of APL, see the Vector special on the first 25 years of Dyalog Ltd.

Supporting the Community – Update

You may have been wondering what has been happening with Jo Shaw (daughter of our Customer Account Manager, Karen) the England pool player who Dyalog have sponsored in the past, so we thought it was time for an update.

After getting a new job in December 2014, Jo moved from Hampshire to Wiltshire and joined the Wiltshire Ladies county pool team. After a successful first season with them, Jo again qualified to play for England as a reserve player in May 2016 but the exciting news that she was expecting a baby meant that she was not able to take up her place in the team – unfortunately the Nation’s Cup event was happening at the exact same time the baby was due. Jo also found that she was not able to practice or play pool during the later stages of her pregnancy as she was just not able to bend over the table(!) so this meant she had to take a back seat with the Wiltshire Ladies county team too.

Jo’s daughter Remy was born on 18 October 2016 and Remy has been a keen supporter of Wiltshire Ladies since she was born – she even has her own team shirt!

Jo and Remy have recently been to the EBPF National Finals to support Jo’s Wiltshire teammates as they became National Ladies Champions for the first time. Jo was disappointed that she wasn’t able to play a bigger part in the victory but being a mother is now her top priority and she was pleased that her team did so well.

After a lot of thought Jo has now made the very difficult decision to take some time out from both county and national pool to concentrate on being a mum. She plans to be back in a year or so once Remy is a bit older and Dyalog fully expect her to win back her place in the England team – we will be there to support her when she does!

Dan Baronet

Dan Baronet

Dan Baronet

We do not know the details, but Dan’s luck ran out this week. On Tuesday, as he headed South from Nevada into California, en route to Mexico on the first leg of a four month motor cycle adventure to South America, something went wrong … Dan lost control of the bike and collided with a motor home, and many of us are now struggling to comprehend that Dan won’t be back.

Dan made friends everywhere that he went. On our annual Dyalog skiing “retreat” (we frequently did real work on prototypes of new tools, honest!), I was always impressed (while trying to hide my slight embarrassment) by the way Dan always kicked off conversations with hotel staff. Whether the waiters and waitresses were native Italians from the resort town – or migrants as hotel staff frequently are – Dan would typically know enough words in some shared language to get the conversation off to a good start (or he would extend his vocabulary on the spot). This always guaranteed us service with a smile, and excellent advice on which wine to order for dinner.

Dan gave as well as he got: on the slopes, Dan was always the first to stop by anyone who had fallen over and was struggling to get back up. Dan has friends all over the world and always took the time to visit them when he could, to keep the friendships alive. He was also happy to open his own home to travellers, both my kids had little Canadian adventures as guests of Dan and his family in Quebec, and Dyalog team members would also “couch-surf” chez Dan.

At work, Dan also loved extending his vocabulary. He remembered more details of different APL dialects than anyone else that I know, and was an expert in migrating code from one system to another. He also knew the weaknesses of each system, and was a feared visitor to vendor booths at APL conferences. Dan would mischievously sit down to play with a new APL system, try a couple of his favourite edge cases, and usually manage to crash new (and some old) APL interpreters within seconds.

But even when crashing interpreters, Dan was really trying to help the vendor produce a more stable platform. At work, as on the ski slopes, Dan was one of the few people who was always going out of his way to help. When he had spent time learning a new technique, or how to use a new tool, he would go the extra mile to create a utility library, document it, presented it at conferences and APL user meetings. He also did the really hard part – writing an article about it, making frequent contributions to Vector and other publications: http://archive.vector.org.uk/?qry=baronet&submit=search. He also enjoyed teaching APL, as an instructor at I.P.Sharp Associates and in the modern era as the author of numerous tutorials at https://www.youtube.com/user/APLtrainer.

More than 30 years ago, as an APL rookie at I.P.Sharp Associates, I was fortunate to meet, work with, and learn from Dan when he and I both found ourselves at IPSA Copenhagen. In addition to a general interest in tools, I shared Dan’s interest in the migration of code between APL systems, and flying airplanes. Dan actually flew small aircraft (and helicopters!) and I, like so many other friends and colleagues, admired him and got invited along for rides.

A decade and a half later in 2005, as the new CTO of Dyalog, I was keen to add an APL toolsmith to the company. Despite his location in Montreal, Dan was at the top of my list. Dan continued to live in Montreal but was a frequent guest in Bramley, coming over several times a year to spend some weeks to work with the growing “APL Tools Team” – and with the core development team on improving the quality of the interpreter by crashing it in as many ways as he could think of.

When his imagination ran out, he wrote code to generate even more ways to crash the interpreter. Dan has been cursed loudly many times, and will be remembered – if for no other reason than that it will be a long time before we are able to close the last “issues” that he logged in our problem tracking system. The quality of Dyalog APL has increased enormously in the last decade, and we have much to thank Dan for. Dan also “poured the concrete” for the foundations of the source code management tool (SALT) and the User Command framework that we are all starting to take for granted, and contributed to many other pieces of our growing collection of tools.

C-GSXN in Toronto

Dan often flew himself to APL User Meetings

Dan was an adventurer. He skied, snowboarded, snowshoe’d, biked, skated, hiked and flew – and with his great sense of humour and warm personality, he was able to entice many of us to come along with him to share. He photographed and brought his video camera, although he would often manage a 3-week trip to Europe which included a skiing trip, carrying only a small backpack.

Dan had just turned 60, and he had taken four months leave this winter to pursue an old dream to revisit South America with a friend – on motor cycles. They had wisely gone on a trial ride in the late summer, riding from Canada to Las Vegas and parking the bikes there in order to test the equipment and not have to ride two-wheelers in the Canadian winter. As a pilot, Dan understood risks very well – or rather, how not to take unnecessary ones.

“If only he had been a little more cautious”, some will say. Was that trip really necessary? These thoughts are unavoidable – but we have to remember that his decision to ride was natural to the adventurous and mischievous spirit that we all knew and loved.