Yearly Archives: 2023

Dyalog ’23 Day 2: Looking Into the Future

Posted on by

The weather improved today – the sunshine was a refreshing feeling as we awoke to a new day of forward-thinking presentations.

As usual, we began with Gitte Christensen’s welcoming address in which she spoke of the exciting new growth happening at Dyalog Ltd. Five new employees have joined since we met in Portugal last year for Dyalog ’22, addressing our increasing needs for tools, administration, IT support, testing, and marketing. In addition, approximately a quarter of the delegates at Dyalog ’23 are attending for the first time. However, we also said goodbye to Geoff Streeter, one of the original implementers of Dyalog, as he retired this year (read about Geoff and his charity work in this blog post “Not All Heroes Wear Capes”). Gitte herself is stepping down from managing the company at the end of the year, and has been spending the last couple of years training her replacement as CEO, Stine, to take over in January 2024.

Gitte Christensen welcomes us to the user meeting for her last time as CEO

There are two large projects that Gitte has been championing before her retirement. The first is the formation of the APL Trust Fund – a charitable foundation to enable individuals and companies who have enjoyed and benefited from APL to pay it forward with a fund dedicated to science and technology research, and in particular that which can help promote the use and development of APL. The second is a new website for Dyalog Ltd, which is progressing well; she showed us a preview of the home page and a searchable library of APL videos.

Morten Kromberg then presented his insight into what this rapidly growing team is up to. After reflecting on the milestones of historic Dyalog development, such as the introduction of namespaces and the Win32 GUI interface, he talked about many of the ongoing projects that will be presented this week as well as his hopes for version 20.0 and beyond. For example, Dyalog on 64-bit ARM processors, academic collaborations in quantum computing, metallurgy and teaching; tools for asynchronous programming; package management; performance improvements, an application health monitor, and much, much more.

Morten Kromberg gives an overview of new development work happening at Dyalog Ltd

Next, John Daintree presented an update to the so-called Token-by-Token (TBT) Tracing – or is it primitive debugging? or should it be called “Bit-by-Bit Poking”?! The ability to do fine-grained tracing function-by-function within expressions clearly has incredible potential for development, teaching, and learning APL. Those with a tacit aversion can see exactly how derived functions and trains are executed, and everyone can benefit from seeing the values of variables in the debugger as expressions are traced.

Then Adám Brudzewsky presented his ideas on how to address a range of issues when you want to assign a variable but the name itself is variable – this is often a problem when using namespaces as dictionaries, for example. Although possible, he showed how incredibly unwieldy it currently is to do this with good performance. He proposed system functions for getting name-value pairs (⎕NV), getting a name (⎕NG) and setting a name (⎕NS). If you recognise the last one, luckily his proposal is a consistent extension of the current ⎕NS system function.

Peter Mikkelsen had another system function proposal as he elucidated current issues with the way we call shell commands from Dyalog with ⎕SH and ⎕CMD. His proposed new system function might include features such as whether to error on a non-zero exit code and ways to redirect input and output. This proposal is quite concrete, and if all goes well it might see its way into version 20.0.

Acknowledging that it might be of little interest to some users and yet deeply fascinating for (and requested by) others, Richard Smith gave us a privileged view into the technical content of the workspace and how memory allocation works. Essential viewing for users concerned with performance, the “pocket allocation algorithm” shows what really happens when a WS FULL error occurs.

John Daintree and Richard Smith discuss the internal workings of the interpreter

Furthering the discussion of interpreter performance, Karta Kooner continued the analysis he presented last year of the performance of set functions that use search algorithms, such as membership ∊ and index-of ⍳. His heat maps of performance using different data types with arrays of sizes ranging up to 1,000 or 20,000 elements, showed v18.0 having unexpected degradation in many cases. Of course, it is significantly faster in some cases, so Karta intends to address the algorithm selection issues and then re-introduce successful algorithms from v18.0.

On the topic of concurrent programming, Stig Nielsen of SimCorp demonstrated using .NET tasks to implement “APL Worker Bees”. By exporting an APL class as a .NET assembly, a main APL process can be used to control many interpreters working in parallel across all of the cores of the machine. In contrast to isolates, these are several APL interpreters running in the same machine process, which Stig needed when migrating his specific application to the cloud.

Mark Wolfson

Mark Wolfson returned to the stage after his fascinating presentation last year in Portugal to talk about his efforts streamlining a complex data processing and analysis pipeline. Previously, he had used C# tools to ingest data from over 40 different software systems used by U.S. jewellery retailers and some APL “black boxes” to normalise the data. He has been able to replace all of that with Dyalog tools, allowing him to rapidly make changes that previously took days, weeks, or months. He has also shown these tools to members of his C# team and said that they really resonated and he now has C# programmers wanting to learn APL! Mark urges the APL community to promote APL as an excellent “glue” language to bind together the already-familiar tools used by programmers.

Kai Jaeger

Of course, the APL world still needs its own tools. Kai Jaeger has been developing the APLTree library for many years. We saw a brief history of Kai’s library of tools before he provided an update, including the move to make them available on the Tatin package manager that he has been developing for Dyalog. There was news of specific updates to packages such as FiRe (Find and Replace), which is a tool for searching and replacing within code and names in a Dyalog workspace, and the addition of new packages for reporting code coverage during testing, an FTP client, accessing the GitHub API, and using SMTP for email. He also introduced the Launchy application, which is useful for users when starting Dyalog when they have multiple versions installed.

In the last talk of the day, Morten shared the status of package management in Dyalog more broadly. In exciting news, he demonstarted how the Cider project manager now supports adding both Tatin and NuGet dependencies to an APL project, making it easy to use the dozens of APL packages or hundreds of thousands of .NET packages.

After dinner we were treated to some light entertainment in the form of a remote presentation by Ray Cannon, who has been experimenting with synthesising music from APL. Hearing the development of sounds from simple sine waves through to added overtones creating a fairly convincing organ was quite fascinating, and the synchronised animation of falling piano keys to J.S.Bach’s Toccata and Fugue in D minor was magical.

Today’s presentations:

Email, RSS Follow

Dyalog ’23 Day 1: Welcome to Denmark!

Posted on by

We have returned to the (very windy this time!) shores of Elsinore in Denmark for our annual user meeting, Dyalog ’23!

Today saw the usual range workshops in which everybody could get involved learning the intricacies of a range of topics with the support of experts from Team Dyalog and friends.

In the morning, users in part 1 of the Projects and Packages workshop started consuming APL packages using the Tatin package manager. While many existing users have gone decades without these very convenient additions, we see packages as an important part of APL’s future.

In the Tacit Techniques workshop, participants learned the basics of function composition operators and function train syntax. They practised spotting patterns to make explicit code more succinct, and even those who only started using APL earlier this year had great success converting explicit functions into those that do not mention their arguments.

Meanwhile, users who wanted a challenge tackled an advanced workshop focussing on common pitfalls when writing code that performs well.

Projects and Packages workshop with Morten Kromberg, Kai Jaeger, and Gilgamesh Athoraya

In the afternoon, we hit the rate limit on the GitHub API during the session on web services, as presumably everyone on the venue’s Wi-Fi network had the same I.P. address! Fortunately, after each user successfully configured a web service on their own machine, everyone could experiment as much as they wanted to.

In part 2 of the Projects and Packages workshop, participants managed to publish their own APL packages to the Tatin test registry for others to use. Now that they’ve had a taste, we hope to see more become available on the main Tatin registry in the future!

The development masterclass took participants through some basic and some lesser-known features of Dyalog’s Integrated Development Environments. Some newer APLers said that they learned a lot, and even more experienced users said they had benefitted and would take the materials back to their organisations to share with others.

Adám Brudzewsky and Stefan Kruger host a masterclass on the features of the IDEs

Conversation over dinner included catching up with long-time friends and making new ones, stories of onboarding new APLers (some of them in attendance), and hearing about personal and professional achievements of the last few years. There’s excitement in the air this evening, and we can’t wait to start a fantastic few days of presentations tomorrow!

Email, RSS Follow

Welcome Stefan Kruger

Posted on by

Stefan Kruger recently joined Dyalog Ltd from IBM, where he worked on distributed databases for many years.

Stefan spent a long time at university doing research in signal processing; after that he worked in several start-ups that were closely tied to the academic world. Then, taking a step away from technology for a while, Stefan pursued his interests in climbing and skiing, chasing winter around the globe until the money ran out.

Once safely back in gainful employment, Stefan set himself a goal of learning a new programming language each year, favouring those that are less mainstream…”the weirder, the better!”. This path has led him through such languages as Zig, Clojure, Elixir, Racket, Haskell, and many more. Once he discovered APL he was hooked. Recognising the need for more accessible resources while learning APL, Stefan wrote Learning APL, an introductory book for programmers familiar with other languages; he also edited together APL Cultivations, which covers most aspects of basic APL programming as well as some more in-depth lessons.

Stefan lives in Bristol with his wife Sarah, two cats, one dog, and n+1 bikes. He enjoys back country skiing in arctic Scandinavia or Canada during his winter holidays. In the summer, he stays active by road biking, especially climbing the classic cols in the Alps — strictly “type 2” fun.

We’re glad to have Stefan on board at Dyalog Ltd; his background and drive for continuous learning should be a positive contribution to our team, and we look forward to seeing his contributions to the APL community.

Email, RSS Follow

Employee Spotlight: Peter

Posted on by

This week marks the first anniversary of Peter joining Dyalog Ltd. He is one of the newest additions to Team Dyalog and we couldn’t be more excited for his future here. We were able to pry him away from the interpreter to catch up with him and see what his time has been like so far.

Peter joined Team Dyalog after studying at Aalborg University, where he received his Bachelor’s degree in computer science. APL made an impression on him when he heard about it in 2021; he found it fresh and pleasantly new. APL (and Dyalog APL) were different from other programming languages he had dealt with.

Most days Peter is deeply involved with Dyalog’s interpreter; he improves it by implementing cool new features and fixing any annoying bugs. Peter really enjoys the affable and cooperative culture here at Dyalog Ltd, “It is a very friendly crowd, and everyone is willing to help me with whatever issue comes up.” He also enjoys his role in the development team. He finds it challenging and fulfilling to work on issues that require him to look at and understand a part of code that he hasn’t seen before…it’s like solving a puzzle for him, and when things start to ‘click’ he gets really motivated because he knows, “that the system is becoming more and more robust with every bug fix.” Peter’s role requires a lot of critical thinking, “I think the most important skill is to be able to navigate and make sense of old code on your own.”

When he’s not improving the heart of Dyalog, you can find Peter spending his time outside! (I know, shocking for a programmer!) He enjoys scenic walks in the picturesque nature local to him in Denmark, which is a huge juxtaposition from staring at screens for a living.

Peter is a great addition to the team, and we wish him all the best on his one-year anniversary at Dyalog Ltd.

Email, RSS Follow

Welcome Jada Andrade

Posted on by

Jada moved to the United Kingdom in 2015 to pursue a degree in law with politics at the University of Manchester. On graduation she relocated to Reading in the south of England, where she took on various temporary positions in administration during the Covid-19 pandemic.

Jada first heard about APL when her partner, Rich Park, joined Dyalog Ltd in October 2018. Since then, she has attended various Dyalog Ltd events as a guest, including Dyalog ’19 and Dyalog ’22, and found the enthusiasm and passion of the APL community infectious, despite having little to no experience in computing. Attending these events left Jada with a very positive impression of Dyalog Ltd, particularly with the logistical planning and administrative organization evident from the smooth running of each event. She was also in the unique position of being able to interact with Dyalog Ltd employees prior to joining the company, fostering good relationships through casual communication.

Therefore, when the possibility of joining Team Dyalog as an administration assistant and office manager was brought up, she immediately jumped on the opportunity and officially joined the company towards the end of March 2023. She hopes to lessen the current workload of the administration team, and enjoys the varied nature of her role as she gets to explore legal, finance, customer relations and office management tasks.

Outside work, Jada enjoys improving her running skills, taking long walks in the bountiful nature of Berkshire, occasionally canoeing, discovering cool Japanese manga, and making delicious dishes in the kitchen.

Email, RSS Follow

Formal Proposal for APL Array Notation – Seeking Feedback

Posted on by

One of the defining features of the APL language is the ability to denote numeric vectors directly through juxtaposition — separating the elements by spaces, as in 0 1 1 2 3 5 8. The notation for character “vectors” is similar to that for “strings” in most other languages, using quotes to denote the start and end of a list of characters. When generalised arrays were added to the language in the early 1980s, the most popular APL dialects extended the vector notation to allow nested arrays to be written using so-called strand notation, allowing the juxtaposition of sub‑expressions producing arrays to form a one-dimensional array — as in:

      (2+2) (FOO 42) MAT

Strand notation works well for small, relatively simple one-dimensional arrays. As soon as arrays are too large to be represented on a single line of code, deeply nested, rank greater than one, or (in APL systems that support them) contain namespaces or objects, APL requires the use of primitives or system functions to assemble them from simple components.

The flexibility of the APL language has allowed many APL programmers to work around the issue, either by implementing custom array notations or by using the ability of most APL interpreters to simply store arrays within saved workspaces without having an actual source form of the data. Within specific applications, domain specific notations can be very successful, but readability is poor for anyone not trained in the specific variation used — or who is missing the tooling required to interpret them — as well as sometimes having significant run-time cost.

Recently, the need for a better notation for arrays has grown within the Dyalog APL community:

  • The switch to text-based sources means that arrays that represent constants, enumerations or initial values — that arguably constitute part of the source of an application — need a textual representation if they are to be managed using the same tools as functions and operators.
  • The increased use of namespaces and name/value pairs as arguments to both user-defined and system functions makes the lack of a good notation for namespaces painful.

Dyalog Ltd intends to implement core language support for a notation that makes it possible to write most arrays literally, without requiring the use of primitive functions, over multiple lines of source where this increases readability. It can be used to write nested arrays, and arrays of rank greater than one. The notation also describes many namespaces/objects, providing both inline and anonymous definitions.

Acknowledgements

Although I used the word “recently” above, the foundations for the notation which gradually evolved into the proposal that we are publishing today were laid by Phil Last at Dyalog’15 in Sicily. At Dyalog, Adam Brudzewsky has been the torch bearer and is the author of the current proposal. We would also like to recognise the contributions of Marshall Lochbaum and dzaima, who have acted as sounding boards and have implemented notations similar to that proposed here in the APL-derivative BQN and in dzaima/APL respectively.

Download the full proposal document

Experimentation within Dyalog APL

Experimental implementations using APL models are available within some tools in the Dyalog eco-system, such as the Link tool (which supports the representation of code and data in Unicode text files) and the functions Serialise and Deserialise within the namespace ⎕SE.Dyalog.Array. You can also try it out in the interactive online sandbox.

Providing feedback

Dyalog Ltd is keen to have feedback from the array language community on the notation proposed here, so that we can feel confident about the design before we proceed with our implementation. Our hope is that we will be able to keep the differences between future array notations within the family of array languages to a minimum.

You can leave feedback below or in the APL Orchard chatroom, the APL Farm’s #apl channel, the r/apl and r/apljk subreddits, and the comp.lang.apl newsgroup, all of which we will monitor. (See APL Wiki for information about these forums.) In addition, we have created a topic in our own forum. If you prefer not to comment publicly, then please send comments by e-mail. We will update the discussion page for APL Wiki’s Array notation design considerations article to contain a record of significant feedback.

Email, RSS Follow