A message from the CTO

Hello! Further to Morten’s kind words of introduction, I’d like to take this opportunity to introduce myself as the new CTO of Dyalog Ltd.

About me

I’m a newcomer to APL. When I started working for Dyalog in 2010 I had only seen the Game of Life video, an intriguing but baffling glimpse into a world of squiggles. But I soon got the opportunity to learn from some giants of the language, and came to appreciate the power and beauty of the notation. Later I learned that, despite its venerable history, the language is not set in stone; with care and attention we can develop and extend it to increase its power, relevance and performance, without sacrificing its elegance and simplicity.

We — not just Dyalog, but the wider APL community — are guardians of a rare thing: a language born more than 50 years ago that is not just relevant and useful today, but groundbreaking in the way it embodies data parallelism from the ground up in a simple, consistent notation.

Before working at Dyalog I spent 13 years developing compilers, optimisers and debuggers for more mainstream programming languages, including C and Java. This has given me a good insight into how to get the best performance out of modern computer hardware, and I’ve made it my continuing mission to help bring that level of performance to APL!

My rôle

As CTO I’ll be responsible for day-to-day management of the core interpreter development team, and for the overall technical strategy of the company. This strategy must include getting the maximum performance out of current and future hardware, but also:

  • Keeping the quality of the product as high as possible.
  • Embracing new platforms and attracting new users.
  • Improving our development tools, and making it easier to create and deploy new applications.
  • Ensuring that Dyalog APL can interoperate smoothly with modern frameworks and services.
  • Continuing to look at new ways of (carefully!) extending and improving the core APL language.

I’m looking forward to working on this alongside the “new” CXO, Morten. At Dyalog we take a lot of care in the design of new features, and I firmly believe that a lively discussion between CXO (representing the needs of the customer) and CTO (representing the language designers and implementers) will only improve the quality of the designs we come up with.

On the road

In the future I expect to spend a bit more time out and about, showing off Dyalog APL, and talking to all of you about your own needs and expectations of the product. In particular, this year I’ll be at DYNA16 in Princeton in April, and the Dyalog ’16 User Meeting in Glasgow in October. I look forward to seeing, or meeting, all of you soon!

Posted in CTO

SWEDAPL Meeting in Malmö, November 11th 2015

The November cycle of APL User Meetings is kicking off; the SWEDAPL meeting in Malmö was first this year, holding a meeting at the top of the famous Turning Torso in Malmö. Since it was just a short trip from our Danish office, Dyalog was represented by Gitte Christensen, Bjørn Christensen and Morten Kromberg – with Brian Becker and Dan Baronet joining the meeting remotely. Next week, Richard Smith and Nick Nickolov will be representing Dyalog at APL Germany in Erfurt and Dan Baronet at FinnAPL in Helsinki – check http://dyalog.com/dates-for-your-diary.htm periodically for a list of APL meetings and Dyalog presentations!

Gilgamesh Athoraya welcomes us to SWEDAPL

Gilgamesh Athoraya welcomes us to SWEDAPL

This turned out to be a very international group – ten Swedes (two of whom were from India but based in Göteborg), six Danes who made the trip across the sound, two from the UK, one German and one delegate from each of Serbia and the Ukraine – plus about five North Americans who joined the afternoon sessions via GoToMeeting. This was the first “themed” SWEDAPL meeting; all of the talks were related to the use of Web Services in APL.

First up was our host Gilgamesh Athoraya from Data Analytics in Malmö, who showed us how he had been using Paul Mansour’s new RUMBA application interface which is built on top of Dyalog’s TCP toolkit (which is known as CONGA). Gil has been experimenting with support for Web Sockets, which are bi-directional connections that allow the server to push data to web client applications, making it possible to have very responsive user interfaces in web applications.

Joakim Hårsman explaining how slippery SOAP can be

Joakim Hårsman explaining how slippery SOAP can be

The next presentation was by Joakim Hårsman of CompuGroup Medical, who have been exposing data held on IBM AIX servers via Microsoft.NET-based Web Services for many years. Joakim had a few interesting stories to tell about getting a grip on and maintaining Web Services based on the protocol known as SOAP, which is supposed to make this easy…

The last talk before lunch was by Stephan Poßberg of Vallourec, who talked about the use of Web Services to make computational code available across a large, global organisation. Lunch was served on the 54th floor; unfortunately the weather didn’t quite allow us to see all the way to Helsingør.

The Turning Torso in the Mist, After Dark

The Turning Torso in the Mist, After Dark

After lunch, it was Morten’s turn, assisted by Brian Becker (who joined the meeting from Rochester NY) to present Dyalog’s brand new support for RESTFul web services, available in MiServer 3.0. Paul Mansour also joined this session and provided valuable insights into REST technology, which seems to be taking over as the preferred Web Service architecture for new applications.

Finally, Peter Simonsson from Aplensia in Göteborg told us how Web Services had become widespread at Volvo Cars, where a couple of hundred APL-based services provide the backbone of a network of applications centered around product data and production planning – with the earliest web services dating back to the days when APL ran under VM on IBM Mainframes.

Many thanks to Gilgamesh, Data Analytics and Optima Systems for arranging this event, which provided much food for thought, and inspiration for future work by several people at Dyalog – and by the sound of it, a number of users of APL as well! Expect to see more support for Web Services and Sockets in future versions of Dyalog products!

Over the Moon with Selenium

Over the years, I have become more and more reluctant to write code without good regression tests – 35 years of software development have taught me that it is just too dangerous! Regression testing of user interfaces has always been difficult, but for the last few weeks I have been working with technologies that put user interface testing within easy reach: HTML and the Selenium WebDriver, which star in the following video (if you can wait, read the full story below the video before watching):

This is exciting – I hope you can see why I am “over the moon” (apart from Selene being the Greek Moon Goddess).

Modern Markup Languages

One of the good things about modern User Interfaces based on markup languages like HTML is that logical information about the user interface is available at runtime. For example, a browser displaying HTML maintains a “Document Object Model” of the web page. The content and other attributes of each element within the DOM can be inspected and manipulated at runtime by a testing tool – this is what Selenium does.


Selenium is a widely used open-source tool for automating browsers, with growing support from browser vendors. Selenium provides an API that allows you to perform just about any operation that a user could: click on buttons and select items from drop-downs, press keys to enter text, drag and drop items, or perform exact mouse movements and different types of clicks. Over the last few weeks, we have been working on a some thin covers for Selenium to make it easy to drive browsers from Dyalog APL. At the moment we require the Microsoft .NET bindings and can only do the testing from Microsoft Windows. The web server can be running anywhere, and we hope to add other client platforms in the future.

The results of this work are now available in the GitHub Repository Dyalog/Selenium. The following example, included in that repository, shows a simple test which verifies that the TryAPL website is able to execute a simple expression:

 ∇ r←Basic;S;result
 ⍝ Basic test that TryAPL is working - return error message if it isn't
 'APLedit'S.SendKeys'1 2 3+4 5 6'
 S.('APLedit'SendKeys Keys.Return)
 r←result S.WaitFor'5 7 9' '1 2 3+4 5 6 failed'

MiServer Regression Testing

The primary motivation for this work has been to create regression test scripts for MiServer version 3.0. The MiServer regression testing mechanism is extremely simple (possibly a bit TOO simple, we’ll cross that bridge later): If a site contains a folder called “QA”, and the folders within mirror the structure of the web site, then a mechanism exists to load each page in turn and run the corresponding test function. You can read more about it on GitHub and see it working in the video at the top of this post.

Spring 2015 Dyalog Travelogue (An American Tale: Dyalog Goes West)

Concluding Morten and Gitte’s whistlestop tour round Europe before heading to the US (see parts 1 and 2)

Saturday afternoon feels like Déjà Vu all over again...

Saturday afternoon – Déjà Vu all over again…

On Saturday afternoon we passed through London’s Heathrow airport for the third time in 5 days, this time continuing west to JFK, bringing the total for the week to 8,943km plus 300-odd in 3 different cars, 220 by rail, 25 by bus and 5 on the ferry 🙂 .

Sunday was spent with some of Dyalog’s North American contingent, co-ordinating and putting the final polish on the coming week’s presentations.

On Monday morning we were ready to start the first Dyalog North America user meeting – DYNA’15. The Princeton Crowne Plaza was our venue – making this our third time there after Dyalog ’07 and Dyalog ’09.

Back at the site of Dyalog ’07 and Dyalog ’09 – the Crowne Plaza in Princeton, New Jersey

Back at the site of Dyalog ’07 and Dyalog ’09 – the Crowne Plaza in Princeton, New Jersey


We had 37 visitors on Monday and 25 on Tuesday – a total of 45 different delegates representing about 15 different clients turned up to listen to updated road maps, demonstrations of new tools and four half-day workshops on Recent Language Enhancements, Parallel Programming using Futures and Isolates, Web Application Development and Modern APL Application Architectures. While there were no user presentations this year (the potential presenters seem to be keeping their powder dry for Dyalog ’15 in Sicily in September), we nonetheless had a full schedule.

Woodley Butler of Automatonics, Inc had been due to make a presentation, but had a scheduling problem and was unable to come. Gitte presented his exciting new hosting solution for Dyalog APL: APLCloud.com, during the opening session on Monday.

Monday’s dinner may have been the highlight of the event. We traveled (longer than expected due to the shuttle driver getting lost) to Mimino’s Restaurant for an authentic Georgian meal. The word meal does not do the experience justice – it was a culinary extravaganza – with plate after plate of incredible Georgian food. Imagine everyone’s surprise when we were told that it was now time for the entrees! Good friends, good food and good drink made it a truly special night.

After a meeting in Princeton on Wednesday morning we hit the road, again, this time to the Poconos to spend a few days relaxing and working with the North American Dyaloggers on a variety of projects before wrapping this tour up with visits to clients next Monday and Tuesday.

Spring 2015 Dyalog Travelogue (The Saga Continues)

Continuing Morten and Gitte’s whistlestop tour round Europe before heading to the US for DYNA15

From left to right this time…

From left to right this time…

FH Bingen – must have good student parties?

FH Bingen – must have good student parties?

Day 3: Bramley-Bingen

Job interviews done by lunch-time, and we hopped in the car (without lunch) to Heathrow, flew to Frankfurt and finally arrived at Bingen at sunset, just in time for some Weissbier and Flammkücken with the other early arrivals. Bingen is located west of Frankfurt, where the Rhine leaves the plains and bends north through hills, heading for Köln, Düsseldorf and the North Sea. Separated from the river by a vineyard-covered hill lies Fachhochschule Bingen, where our, host Dieter Kilsch, uses APL with MatLab and other tools to teach students about quality control and other subjects.

Days 4 & 5: APL Germany Spring Meeting in Bingen

We spent the next two days in the company of about 25 German APL enthusiasts. This time we were first up with a 2.5 hour workshop on Futures and Isolates, and we were very pleased to see that all the delegates who had gone to the trouble of installing Dyalog APL were able to perform all the exercises. We’ll have to make them a little harder next time (Tuesday in Princeton) 🙂 . The afternoon was focused on IBM: News from the Z-series hardware front, and the IBM GSE requirements process, where APL2 users get together and vote on priorities for requests for enhancements. Wouldn’t it be great if our Dyalog users would gang up on us like that and help us to set priorities as a group?

The watch tower at the top of the hill south of Bingen

The watch tower at the top of the hill south of Bingen

The first session on Friday was an APL Germany “business session” which we were allowed to skip. Morten discovered that the Tourist Information office next to our hotel rented bikes. They were a little shocked that he was willing to spend €13 for on hour on a bike, but he felt that he really needed to burn some carbon off the spark plugs. Seems he can’t see a hill without feeling it is necessary to make an attempt to get to the top of it.

With Morten energised after an hour on the bike, it was time to return to the meeting. A couple of presentations were particularly interesting: before lunch, Jürgen Sauermann spoke about GNU APL, which is now 2 years old and up to version 1.5. It is very encouraging to see open source APL systems thriving and promoting the use of APL.



One of the presentations after lunch can only be described as mind-blowing! Jörg Hudelmaier presented a development environment for JavaScript applications, written in Dyalog APL. Jörg was able to prototype JavaScript applications in Dyalog APL, using the WinForms WebBrowser control to render the User Interface, processing callbacks in APL – using a set of APL functions that emulated enough JavaScript DOM support to make his application work. Once he had finished development, he wrote a translator that generated a stand-alone JavaScript application which could run in a browser.

We rounded the two days off with a presentation on our strategy and selected demos of features from versions 14.0 and 14.1: Key, the new experimental JSON parser/generator and the Compiler, threw ourselves in the rental car and headed to Denmark for 15 hours at home before we set off for JFK and Princeton. The story continues next week, on the other side of the Atlantic!

To be concluded…

Spring 2015 Dyalog Travelogue (Ferries, Trains, Planes and Automobiles)

The journey begins: Kronborg Castle, Helsingør

The journey begins: Kronborg Castle, Helsingør

Göteborg: Läppstiften and Barken

Göteborg: Läppstiften and Barken

One of my favourite times of the year is the period in March/April where we traditionally start with a visit to the FinnAPL Forest Seminar followed by the APL Germany Spring Meeting. This year there are two new stops to make: the Swedish APL Group has started holding meetings twice a year too – and we are running the first Dyalog North America meeting in Princeton.

The FinnAPL meeting was a few weeks ago; this week we are wrapping up the rest in a whirlwind tour of no less than five one-way trips to get us to Princeton late on Saturday.

Day 1: Helsingør to Göteborg

We were off to a beautifully easy start on Monday evening, with the 20-minute ferry ride from Helsingør, where Gitte Christensen and I live, to Helsingborg in Sweden. From here it was 1 hour and 45 minutes by snabbtåg (train) to Göteborg, where we arrived just in time for a run at sundown, over the bridge across the Göta river, from which the second image was taken. Our hotel, the beautiful ship Barken, is on the right, and the conference venue, Läppstiften (the Lipstick), a very short walk away to the left.

Day 2: Göteborg to London

Gitte catching some, er, fresh air outside the Hotel Barken

Gitte catching some, er, fresh air outside the Hotel Barken

After a good night’s rest we were welcomed on the 21st floor of the Lipstick by Lars Wenztel of Aplensia, our host for the day. Lars opened the meeting with a talk about the efficiency of using arrays to do product configuration and production planning at Volvo Car Corporation, which is also located just across the river from the meeting site. He mentioned how his team had been working to improve performance, and I would like to take that opportunity to remind you all to send us benchmarks that are representative of your most performance-critical application components so that we (Dyalog) can help you to speed things up.

I was up next with an updated Road Map presentation and demos of the new JSON parser and external workspaces (spoiler alert: Germans and North Americans will see something very similar later this week 🙂 ). The afternoon was full of interesting presentations on the use of APL, with Gert Møller from Genokey in Denmark as the last presenter. He brought the day to a close with his presentation of ongoing work on the application of array-based logic to the problem of reducing the cost, increasing the effectiveness of – and reducing the side-effects that patients are likely to experience when using – new drugs. And guess what…he mentioned that performance was important, too.

Front row: Gitte Christensen, Conrad Helgesson, Joakim Hårsman, Jens Andersson, Tina Leijding, Lars Wentzel. Second: Gilgamesh Athoraya, Ewa Svensson, Radha Jayabalan, Jonas Stensiö. Third: Peter Simonsson, Keerthi Thadikamalla, Per Ericsson, Erik Häggblom and feet of Ole Johansen. Off screen: Paul Grosvenor and Morten Kromberg

Tuesday was a wonderful day in the company of some very lively Swedish APL Users. It is wonderful to see how they have put APL to use in important production planning applications at some of Sweden’s largest manufacturing operations, and the rapidly-growing bio-informatics sector was also well represented. We ended the day deciding to meet again on November 11th, with a target focus of web servers and services. Nearly everyone present had either experience of or plans to implement web-based solutions in APL; there will be code reviews and perhaps even have some hands-on coding sessions next time!

spring2015pt1_6The original plan was to take the train and ferry again and have a night in our own beds, but an opportunity to interview two potential candidates for our current job opening had appeared and, since it would be 2-3 weeks before we were back in the UK, we decide to grasp it. One of the benefits of having a large collection of air miles is that you can spend them on last-minute one-way trips that would otherwise cost a fortune. So instead of hopping on the train, we found ourselves on the airport bus and then a BA flight to Heathrow.

To be continued…