11 April 2023 – A Day to Celebrate!

Today we reach two very significant milestones.

40 Years of Dyalog APL

On this day, we have cause for celebration: it is 40 years since the release of Dyalog version 1.0! Geoff Streeter would say that from his perspective we are already in the 42nd year, as he and John Scholes started work on the new interpreter in 1981. On the other hand, Pete Donnelly might argue that the interpreter wasn’t really ready for serious use until a few years after that date. The fact remains that the APL ’83 conference in Washington DC saw the first official release of the product, and is considered to be the “birth” of Dyalog APL.

Farewell Geoff Streeter

On the same day, we also congratulate Geoff Streeter, the last Dyalog developer who will have worked on the interpreter throughout its existence, on the first day of his retirement. We are happy to be able to report that, unlike John Scholes who designed and built version 1.0 together with Geoff but sadly passed away in 2019, Geoff is retiring in good health. We wish him many happy years in retirement in the company of his wife Sarah, children and grandchildren – although we are also hoping that he will pop by the Dyalog office from time to time to let us know how he thinks we are doing, and hopefully also join us at some future user meetings!

Continuity

It is impossible to exaggerate the value of the dedication and continuity that Geoff and John provided to Dyalog over these four decades. In the early days, when company finances were shaky, they sometimes continued work on the interpreter without compensation. Today, we are still blessed with many team members who have worked for Dyalog for most, if not all, of their careers – although we are doing what we can to avoid the need for the extremes of dedication that were required in the early days.

Good Choices

Dyalog APL started its life as a unique combination of what was to become the leading nested array paradigm (APL2/NARS floating arrays) coupled with what John and Geoff (and the rest of the consulting team at Dyadic Systems Ltd) thought were the best “commercial” extensions selected from APL systems developed by STSC and I.P.Sharp Associates (component files and control structures from STSC, error trapping from IPSA, and many other features).

The early choices have stood the test of time, and paved the way for Dyalog to become extremely competitive when Windows 3.1 and John Daintree arrived at the same time – resulting in the extremely easy-to-use Win32 GUI support. In typical fashion, the team did not merely implement a tool for GUI programming, they adopted an approach that led to the very general notion of namespaces, which meant that the same architecture could be used to interface to COM/OLE and subsequently .NET and complete support for object-oriented programming in Dyalog.

UNIX

Geoff was (and is) very much a UNIX man, and the first versions of Dyalog were built for the small UNIX machines that Dyadic Systems expected to take over from the mainframe. Unfortunately, UNIX was slow to gain acceptance and, around 1990 when UNIX was finally starting to take off, Microsoft Windows arrived and the centre of gravity of the commercial business shifted in that direction. Geoff was often heard muttering to himself about how the company was making poor technical choices, driven by what he referred to as “commercial” pressure. He kept his head down, and ensured the UNIX implementations were well supported and that all designs took the needs of these platforms into account.

Users of UNIX-based Dyalog can be grateful for Geoff’s unwavering enthusiasm. And Dyalog too: not only is the IBM AIX version of APL still a significant source of revenue, the ease with which we have been able to add support for Linux and macOS is very much down to our long UNIX history and the goal of maintaining cross-platform compatibility, throughout the history of the product.

Dedication

As a further example of Geoff’s dedication: as a young man with a motorcycle and a keen sense of community, Geoff started riding at night, delivering blood from blood banks to hospitals where it was urgently needed. He started doing this in 1980, just after he started at Dyadic Systems, and, although he is retiring from Dyalog today, Geoff will continue as a volunteer for SERV S&L. Although he no longer rides his bike, he now acts as the controller for the new generation of riders. In October 2021, SERV S&L was presented with The Queen’s Award for Voluntary Service by the Lord Lieutenant of Surrey.

The Future

In the same way that Geoff has not been riding his bike at night, he has not been doing any new development on Dyalog for the last year. Instead, he has been preparing and holding internal presentations to a new generation of Dyalog developers, providing insight into the work that he has done over the last four decades. Ultimately an impossible task of course, but at least they now know where to start digging – and Geoff is still around to answer questions in an emergency if we offer him a cup of coffee and three plain chocolate digestives (his stated minimum requirement to come into the office!).

As Dyalog enters its fifth decade, all parts of Dyalog Ltd. (including the development team) are larger – and broader – than they have ever been. The good choices made by Geoff, John, Pete, and many others in the early years are holding up, and the company continues to grow.

Many thanks to Geoff from everyone at Dyalog Ltd. We will do our best to allow him to relax, enjoy his well-deserved retirement, and look forward to continued dividend payments from the Dyalog shares in his pension fund!

References:

Welcome Peter Mikkelsen

Peter joined Dyalog Ltd in mid-July 2022, shortly after finishing his bachelor’s degree in Computer Science from Aalborg University in Denmark. He didn’t originally plan to look for a job so soon, but when he saw that Dyalog Ltd had an opening involving three of his favorite things (C programming, interpreters, and APL) it was too good an opportunity to let pass and he was offered the job after a couple of online calls and interviews. Peter and his girlfriend had planned to move to Esbjeg in the south-west of Denmark for a while, so he thought it was great that Dyalog Ltd made it possible to work from home. He joined just in time to be able to participate in Dyalog ’22, which meant that he met lots of customers, which he considered a great experience.

His interest in APL started while he was at university – at one point he thought to himself: “This language looks so strange and different that it might be worth learning.” After spending some time playing around with it and participating in the 2021 APL Problem Solving Competition, he started writing his own little APL interpreter, which he says must have been the point of no return for him. Even in the first few months at Dyalog Ltd, he has learned a great deal about the language and its quirks, and a lot about implementation techniques.

Peter hopes to be able to help develop the language in the years to come, and to make sure dfns get the love they deserve, as he thinks that functional programming is definitely the way to go!

Even though he is part of the “young generation” of APLers, writing long trains and doing code golfing in APL has yet to catch his interest.

When not working, Peter is likely to be found taking a long walk, or trying out something computer science related that has caught his interest. Often, the code he writes in his free time is for the Plan 9 operating system, which in his mind is so elegant and simple that it is almost a shame it has so few users.

Welcome Silas Poulson

As is often the case these days, Silas found APL through online programming language discussions – both in various forums and through videos (Aaron Hsu’s Co-dfns and John Scholes’ Game of Life demonstatration in particular) – whilst attempting to understand the more esoteric ideas and their theoretical underpinnings provided by Scheme and other functional languages. After discovering APL, Silas attempted to use it for his Data Analysis coursework, sticking primarily to a small set of primatives. However, hitting WSFULLs with the datasets required meant that APL remained just a fun system to play with, which led to an understanding of where () in terms of other primatives ( and ).

Silas saw one of Dyalog Ltd’s adverts for a C programmer; this was a language he had learnt during his exploration of the Raspberry Pi and its associated add-on boards, so he applied. He joined Dyalog Ltd in June 2022 after graduating from Royal Holloway in England with a bachelor’s degree in Computer Science, and eased his way into exploring the internal workings of the interpreter, where he now spends most of his time.

When not programmaing, Silas can be found enjoying a good book and the occasional summer hike with friends and family.

Not All Heroes Wear Capes

On Friday 15 October, the SERV S&L was presented with The Queen’s Award for Voluntary Service by the Lord Lieutenant of Surrey. Geoff Streeter was one of 20 volunteer SERV S&L members who attended.

What Is SERV S&L?

SERV S&L (Service by Emergency Rider Volunteers for Surrey and London) are a charity organisation, made up entirely of volunteers, comprising motorbike riders, car drivers, controllers, and fundraisers. They transport blood products, urgent samples, medical supplies, and donated breast milk to hospitals and milk banks across Surrey & London, as well as carrying out a daily delivery of blood to the Air Ambulance service that covers Kent, Surrey, and Sussex. They support the regular delivery rounds that the NHSBT (National Health Service Blood and Transport) have in place; unlike the NHSBT, SERV S&L also operate throughout the night. All of this is provided free of charge to the NHS, releasing more money for patient care.

What Is The Queen’s Award for Voluntary Service?

QAVS (The Queen’s Award for Voluntary Service) celebrates the outstanding work of local volunteer groups across the UK. Created in 2002 for Queen Elizabeth II’s Golden Jubilee, QAVS awards shine a light on the fantastic work of voluntary groups. QAVS awards are the highest awards given to local voluntary groups in the U.K. (they are the equivalent of a personal MBE) and they are awarded for life.

Geoff’s Involvement with SERV S&L

A Personal Recollection

At the end of 1980, Paul McCann had a relation who could not get an urgent sample transported to the testing lab until the next morning. He was frustrated by this and organised a meeting to see what could be done, the result of which was that a group of advanced motor cycle trainers from a (now defunct) group called Star Rider decided to try to run a delivery service for blood/samples at night. I was not at that meeting but I heard about it from a fellow member of the Laverda Owners group; I made it to the second meeting (on 8 December 1980) and have been involved ever since. We obtained a room with a couple of bunks in a wooden building owned by MEFAS (Malden Emergency First Aid Society) and a telephone line, and started operating in early 1981.

The main distribution point for blood is located in Tooting and serves London, Kent, Surrey and Sussex (we have partner organisations in Kent, Sussex and Wessex). We do a main nightly run with typically 6 to 10 boxes down to an arranged change point for Kent and Sussex. We also partner with similar organisations across the U.K., and have occasional relay runs, for example, from Edinburgh to central London (I think that’s the longest that we’ve been involved in). More common are runs from Bristol. We typically shift 20 boxes a night and samples in the other direction and have about 8 riders/drivers on shift every night.

Financially, we get support from some Masonic Lodges and business groups. They prefer to buy bikes for us, and Citroen have given us a car (DS3) on permanent loan. We are in the process of acquiring/refurbishing a scout facility in Sutton to provide a base for the bikes/cars/van as well as for volunteers who live on the periphery of the area. We also raise funds by box waving outside supermarkets, garden centres, Brooklands, Waterloo Station, etc.

I started with the group as a biker, and used my Laverda 750, Laverda 1200 and Honda 650 Turbo to deliver blood and samples from 1981 until 1990, when I switched to car deliveries (which I continued to do until last year). I also acted as Treasurer from 2006 until 2010. I have been one of the controllers right from the start [Ed.: Controllers orchestrate the logistics of a shift; hospitals and partner groups place their orders and riders and drivers are dispatched as required – accurate scheduling and data logging are required to ensure efficient co-ordination and communication so that each run can be completed reliably], a role that has changed a lot over the last 40 years. In the early days controllers needed to be physically present with the one rider and the telephone. Then we moved to using pagers (but still needed to be present in the hut/sports centre) before everything changed with the advent of mobile phones – I now control from home. The expectation is that volunteers do one night a fortnight, but a shortage of volunteers relative to growing demand means that for a few years now I have been doing at least one shift a week.

Final Word

Congratulations Geoff, 40 years of volunteering for such a worthy cause is a fantastic achievement. All of us at Dyalog Ltd are really proud of your contribution.

To find out more about the amazing service provided by SERV S&L, including how to make a donation, visit https://servsl.org.uk/.

Welcome Karta Kooner

Karta joined Dyalog in April, and is yet to meet anybody in person although he’s been told that this is not necessarily a bad thing! After completing his doctoral degree in theoretical physics, Karta stumbled upon Dyalog and APL entirely by happenstance. Being often captivated by things that look unfamiliar to him, and having an interest in most things, it was a code golf question that was answered in a strange, yet mathematical-looking language that took him to the profile of the poster, who happened to mention they were employed by Dyalog and currently hiring. He sent an email enquiring about the opportunity and, several remote interviews later, was happy to be hired as a C/C++ developer working on the interpreter.

Karta is one of the few members of the team that knew no APL whatsoever before joining and has been very impressed by Dyalog and APL thus far; he is very much looking forward to seeing how far the language can be taken, with an eye to further developing and potentially encouraging its use in academia and other technical fields of study.

In his spare time, Karta enjoys expanding his knowledge of both scientific and technical pursuits, and tinkering around with software and hardware systems, amongst his eclectic interests. When not found reading papers or learning an unfamiliar branch of mathematics, he will be caught thinking of a new engineering project to occupy his time, or stumbling through learning a new language, or maybe just delighting in the latest vixra paper.

Welcome Rodrigo Girão Serrão

The story of how Rodrigo got his first internship at Dyalog is, in his opinion, a textbook example of serendipity. As 2020 started, Rodrigo began actively participating in an online code golf community, where people try to solve programming challenges in as few bytes of code as possible. Whilst his golfing skills were possibly lacking, the challenges he posted were usually well accepted. Posting many challenges meant Rodrigo got exposed to answers in all sorts of programming languages, from C, Java, Python and JavaScript, to Jelly, 05AB1E, Husk…and APL. Because of the context and the aspect of it, Rodrigo first thought APL was one of those “esolangs” and not a serious programming language.

Rodrigo’s fascination with APL led him to start frequenting The APL Orchard chatroom, where a small number of brilliant people convened to discuss all things APL. Here he met Adám Brudzewsky, who was keen on teaching APL to newcomers, and so began Rodrigo’s journey to learn APL.

His interest in APL kept growing, and he found it to be a simple and expressive language that also incorporated his affinity with mathematics. One day, while lurking in The APL Orchard, Adám asked Rodrigo if he would be interested in taking an intern position at Dyalog…a few emails later it was established that Rodrigo would work as a part-time intern at Dyalog during the Summer of 2020. This enabled Dyalog to make the most of Rodrigo’s skills in teaching and technical writing, and meant Rodrigo could indulge his passion for sharing knowledge about mathematics and programming while still finishing his MSc in Applied Mathematics. After his internship, Rodrigo took some time to complete his MSc thesis before returning to Dyalog to finish what he had started and hopefully to take part in many other interesting projects. When he is not working for Dyalog, Rodrigo may be found leading a Portuguese APL meetup, writing a blog post for his website (mathspp.com), or maybe leading a workshop or course. Other than working, Rodrigo likes to spend time with his loved ones, read fantasy books, eat chocolate, and watch silly comedy movies.