Links to recordings from this day of the user meeting are at the bottom of this post.

Automation, architecture and performance were throughlines of the second day of presentations. Lars Stampe Villadsen from SimCorp A/S provided some advice on how to write tests and gave a live demonstration of a small testing framework together with continuous integration tools which run the test suite every time a change is committed to the project – useful for when we forget to run some tests locally.

Lars Stampe Villadsen talks about testing.

Norbert Jurkiewicz presented his “10,000 ft overview” of automation processes used by The Carlisle Group and described some of the complexities of building distributables according to varying requirements for different customers. He discussed some of the cost considerations to be made when using Amazon Web Services (or any cloud computing service) to leverage lots of computing power to do builds quickly.

Norbert Jurkiewicz discusses automation architecture.

This was followed by Michael Baas with a similar issue viewed from a different angle. He talked about using the ]DTest testing framework to produce code coverage reports – showing which lines of code had actually been executed when running a test suite – and also automating testing across different platforms and versions of the Dyalog interpreter.

Michael Baas shows us the ]DTest framework

Changing tack, we heard the story of getting to grips with semi-global variables in a multithreaded application. Elena Pavarotti of SimCorp Italiana talked about her experience trying to imagine clearly what a complex system is doing so that it is easier to reliably refactor and adapt it to talk to new external systems.

Elena Pavarotti on managing complexity in SimCorp Sofia.

Rodrigo Girão Serrão then told us how himself and Aaron Hsu had implemented a U-Net Convolutional Neural Network from scratch in APL. The comparisons between their implementation and industry standard libraries was very interesting, and then seeing the mapping from diagrams to code showed us how the APL becomes a natural way to express the data flow involved in the system.

Rodrigo Girão Serrão walks us through the U-net CNN in APL.

Delving deeper into more intellectual musings, Justin Dowdy of Semantic Arts – also known for his work on the April APL to Lisp compiler and the May bridge between Dyalog and Clojure – drew some interesting analogies between the Resource Description Framework, used for representing data relationships as ontologies, and points raised in Iverson’s paper Notation as a Tool of Thought.

Justin Dowdy compares Notation as a Tool of Thought and concepts of Data Semantics.

Juuso Haavisto is a DPhil student at the University of Oxford. He brought up some hot topics in computer science academia – static analysis, rank polymorphism and scheduling for multi-core systems – that he believes can be tackled effectively if we can learn to make the computer think a bit more like an APLer.

Juuso Haavisto with three hot topics in computer science academia.

The theme of performance continued when Vali-Matti Jantunen from Statistics Finland compared the performance of some short APL phrases across several versions of Dyalog. Of course, this can be important in an application like PxEdit which processes thousands of text files; a fraction of a second difference processing a single file can lead to several minutes across a job.

Vali-Matti Jantunen on Dyalog performance across versions.

We hope Veli-Matti will forgive us for the performance regressions found in v18.2 (although not slower than v17.1). However, for us it was no surprise, and next Karta Kooner reflected on some of the assumptions made when changes, intended to improve performance, had been implemented over the lifetime of Dyalog APL. He is looking for volunteers to run a version of the interpreter which can gather usage statistics, so please get in touch if you can do this.

Karta Kooner analyses performance in the interpreter.

Presenting the final features of his special Dyalog ’22 Conference Edition of the interpreter, John Daintree talked about the state of asynchronous programming in the interpreter now. Eventually he showed us an interface, in the from of an ⎕AWAIT system function, to unify Spawn (F&⍵) threads, .NET Tasks and Futures and Isolates.

John Daintree with some ideas about asynchronous programming.

Finally, Aaron Hsu’s Co-dfns report showed a new public API for the parser which could be useful for static analysis of existing code and better error reporting within co-dfns. The new code generator written in APL opens the door to targeting more platforms more easily in the future.

Aaron Hsu presents an update on co-dfns.

Today’s presentations (links to recordings will be added as they become available):

• U06: From “I Developed and Tested It” to “I Developed, and My CI Tested It” – Lars Stampe Villadsen
• U07: Automating Application Builds with AWS – Norbert Jurkiewicz
• D07: Test Your Code! – Michael Baas
• U08: Semi-Globals and Multi-Threading are Like Chalk and Cheese – Elena Paviotti
• D08: Implementing the Convolutional Neural Network U-Net in APL – Rodrigo Girão Serrão
• U09: APL on the Side – Justin Dowdy
• U10: Scheduling Array Operations – Juuso Haavisto
• U11: Performance of Dyalog APL – A Historical Perspective – Veli-Matti Jantunen
• D09: Performance Improvements in Set Operations – Karta Kooner
• D10: 2022 Conference Edition Part 3a – Future(s) – John Daintree
• D10: 2022 Conference Edition Part 3b – Future(s) – John Daintree
• D11: Report on Co-dfns – Aaron Hsu

Follow

Links to recordings from this day of the user meeting are at the bottom of this post.

We were welcomed to the 2nd day of the user meeting by managing director (CEO) Gitte Christensen. Everybody could appreciate the emotion and sentiment when she noted the distinct “APL Hum” apparent in the atmosphere at this year’s event.

Managing Director Gitte Christensen welcomes us to the user meeting.

In some exciting news, Stine Kromberg announced that Dyalog’s board of directors have approved an APL fund for education and science. She also made a call to action for members of the APL community to present their stories to the wider world.

Stine Kromberg announces the APL fund

Morten Kromberg’s road map provided an overview of the multitude of projects and requirements Dyalog is to address in the upcoming years. From the need for new APLers to be recruited to replace those career programmers leaving the fold, to developing tools and training resources that can help all users navigate the modern, complex world of interconnected software development and making the user experience more pleasant and consistent across different platforms.

Morten Kromberg presents the roadmap of activity at Dyalog.

Morten later returned to speak about the status of project and package managers for Dyalog. While Carlisle Group’s Dado is an excellent recommendation for those who can adopt its tools and workflow, Dyalog Ltd has employed the help of APLTeam to develop the more agnostic Tatin package manager and Cider project manager, with the hopes of providing a more flexible and extensible set of tools to meet a wider range of needs.

In a double bill of talks from John Daintree, we were shown a special 2022 Conference Edition of the Dyalog interpreter which has features stemming from both internal discussions and projects and our users’ requests and ideas. He reiterated some of the complications of input and output in Dyalog, but showed how the conference edition can more intelligently handle output from the various sources – for example error messages, quad output ⎕←message and output from system commands.

In his second talk, he demonstrated a system for piece-by-piece debugging of inline APL code and functions. We think you will agree that being able to step through the evaluation of a single line of APL has massive implications for teaching, writing and understanding APL.

John Daintree demonstrates inline “token by token” debugging.

Charles Brenner from DNA-View took us on a journey of his discovery of a method of performing numerical integrations in high dimensional spaces – using a kind of Riemann summation (analogous to the rectangle or trapezium methods) using simplexes (multidimensional generalisation of triangle and tetrahedrons).

Charles Brenner talks about numerical integration

Gilgamesh Athoraya presented a recent project by Tiamatica AB to migrate a process planning system from mainframe APL2 to Dyalog in the cloud. This large undertaking began with creating a bridge from Dyalog to APL2, and the challenge continues as code must be migrate to Dyalog while being able to fold in updates made by the APL2 team still maintaining the current software.

Gilgamesh Athoraya talks about migrating APL2 mainframe to Dyalog in the cloud.

Another APL2 conversion, Mark Wolfson of BIG provided some fascinating insights into the world of Jewelers in North America. Many of these business have managed to resist the trend of becoming parts of large conglomerates and have stayed as small, often family owned businesses. This has meant that they usually don’t have sophisticated software for managing their sales and inventories. Mark’s system uses APL to ingest data from an incredible variety of formats and provide insights to help these businesses thrive.

Mark Wolfson gives insight into the world of North American Jewellery retailers.

Unfortunately, Kimmo Linna from Finnair could not join us in person due to his obligations as a pilot. Fortunately for us, his time away from the cockpit during the pandemic led to him developing useful tools and workflows that he was able to show us remotely via video feed. He is using DuckDB to store data and Vega-lite to present it visually, all being driven from Dyalog Jupyter notebooks and connected using bridges that he has published and made available for free on GitHub.

Kimmo Linna presents his Dyalog/DuckDB/Vega-lite/Jupyter workflow

To finish the day, new recruit on the development team Peter Mikkelsen talked about a personal project from before he joined Dyalog: an APL implementation for the Plan9 research operating system. As he explained, it may be lacking performance, documentation and even users, but we could see from his approach and language design choices that he is someone who can bring great ideas to the interpreter development team.

Peter Mikkelsen shows message passing in APL9

Today’s presentations:

• Welcome to Dyalog ’22 – Gitte Christensen and Stine Kromberg
• The Road Ahead – Morten Kromberg
• D03: 2022 Conference Edition Part 1 – Past – John Daintree
• U01: One-Time Pure Mathematician Corrupted by Exposure to APL Loses Moral Compass and Discovers, after Several Mis‑Steps, a Useful Numerical Integration Method – Charles Brenner
• U02: Lift-Off from APL2 Mainframe to Dyalog in the Cloud – Gilgamesh Athoraya
• U03: Rebuilding a Production APL Environment using Dyalog – Mark Wolfson
• D04: 2022 Conference Edition Part 2 – Present – John Daintree
• D05: The P words…Projects and Packages – Morten Kromberg
• U04: A Modern APL Workbench – Kimmo Linna
• U05: An APL to Vega-lite Interface – Kimmo Linna
• D06: APL9 from Outer Space – Peter Mikkelsen

Follow

Arriving to meet the warm sea air is already a refreshing change as this year’s long, hot summer started to close in the weeks leading up to this year’s user meeting. Of course, for some with less far to travel, the warmth is a familiar comfort.

Apartments at the Real Marina in Olhão, Portugal

As delegates arrived on Sunday night we were treated to a lovely surprise – a birthday cake to celebrate Tony Corso’s birthday! Happy Birthday, Tony!

Today we kicked off the user meeting with workshops, giving delegates hands-on experience with a range of Dyalog offerings for application development.

Attendees of Rich Park and Rodrigo Girão Serrão’s language workshops explored different ways to express ideas in APL using both tried and true idioms in the morning and newer language features in the afternoon – they compared expressiveness and performance implications in difference circumstances.

Morten and Josh got participants up to speed with using and maintaining code which lives outside of your workspace in text files, while Richard Smith and Bjørn Christensen showed how to manage and interact with data from outside of the workspace.

Brian Becker guided delegates into the world of SAAS (Software As A Service). It is encouraging to see how straightforward having APL code talk to the outside world can be. As usual, however, the complexities reveal themselves as you delve deeper in to specific use cases and circumstances.

Morten and Josh show how to store source code as text files using Link

Without a doubt, getting to meet our users face to face has already proved to be the greatest enjoyment of the meeting so far. Some familiar faces long since last seen, and others only over a screen. Discussing ideas face to face still retains a value impossible to quantify.

Overall a fantastic beginning to the week and we cannot wait to experience the rest of this week!

Follow