ACCU World of Code

My grandfather, Norman Angier, worked at Churchill’s Toyshop (M.D.1) as the head civilian engineer during WWII. On VE day “Norman Angier felt it was an occasion for fireworks. He therefore acquired a large batch of quite big rockets and proc…

My grandfather, Norman Angier, worked at Churchill’s Toyshop (M.D.1) as the head civilian engineer during WWII. On VE day “Norman Angier felt it was an occasion for fireworks. He therefore acquired a large batch of quite big rockets and proc…

I’ve spent the last couple of days fighting the Android command line to set up a simple project that can run automated tests inside an emulator reliably and repeatably. To make the tests reliable and independent from anything else on my machine, I want…

Made some significant progress for running Tizen on an Orange Pi PC (and hopefully any other SBC with a similar Mali GPU). Main issue was that alignments in TBM (Tizen Buffer Manager) weren’t in sync with what the actual GPU driver expected. With that …

Made some significant progress for running Tizen on an Orange Pi PC (and hopefully any other SBC with a similar Mali GPU). Main issue was that alignments in TBM (Tizen Buffer Manager) weren’t in sync with what the actual GPU driver expected. With that …

I am building a toy project in Rust to help me learn how to deploy things in AWS. I’m considering using Elastic Beanstalk (AWS’s platform-as-a-service) and also Kubernetes. Both of these support deploying via Docker containers, so I am learning how to …

While trying to get Tizen working on my Orange Pi PC, I noticed some strange behaviour in the Linux kernel in that SIGCHLD signals sent to the parent process don’t always set the “si_pid” field correctly. I tracked this down to a bug in the Linux kerne…

While trying to get Tizen working on my Orange Pi PC, I noticed some strange behaviour in the Linux kernel in that SIGCHLD signals sent to the parent process don’t always set the “si_pid” field correctly. I tracked this down to a bug in the Linux kerne…

A corner of the roof of our office building. Even though the sea is just over 350m away to the left, sadly it’s currently off-limits. 2020 is not turning out to be what we expect as – like much of the world – the UK is locked down right now as a resul…

A corner of the roof of our office building. Even though the sea is just over 350m away to the left, sadly it’s currently off-limits. 2020 is not turning out to be what we expect as – like much of the world – the UK is locked down right now as a resul…

is an excellent book by Douglas Adams (isbn 978-0-330-49120-4). As usual I’m going to quote from a few pages. He would insult the universe. That is, he would insult everybody in it. Individually, personally, one by one, and (this was the thing t…

is an excellent book by Douglas Adams (isbn 978-0-330-49120-4). As usual I’m going to quote from a few pages. He would insult the universe. That is, he would insult everybody in it. Individually, personally, one by one, and (this was the thing t…

I was recording some podcast audio tonight and wanted to be able to press a single key when I reached a significant moment, so I could add the times to the show notes. I couldn’t find anything that already did this, so I wrote a tiny bash script. I ran…

is an excellent book by Douglas Adams (isbn 978-0-330-49121-1). As usual I’m going to quote from a few pages. There is another theory which states that this has already happened. The story so far: In the beginning the Universe was created. Thi…

is an excellent book by Douglas Adams (isbn 978-0-330-49121-1). As usual I’m going to quote from a few pages. There is another theory which states that this has already happened. The story so far: In the beginning the Universe was created. Thi…

I previously wrote an overview showing how decision trees work: http://buontempoconsulting.blogspot.com/2019/07/decision-trees-for-feature-selection.html This time, let’s build a decision tree with some data. There are many freely available data …

I previously wrote an overview showing how decision trees work: http://buontempoconsulting.blogspot.com/2019/07/decision-trees-for-feature-selection.html This time, let’s build a decision tree with some data. There are many freely available data …

is an excellent book by Douglas Adams (isbn 978-0-330-49119-8). As usual I’m going to quote from a few pages. Far out in the uncharted backwaters of the unfashionable end of the Western Spiral Arm of the Galaxy lies a small unregarded yellow sun…

is an excellent book by Douglas Adams (isbn 978-0-330-49119-8). As usual I’m going to quote from a few pages. Far out in the uncharted backwaters of the unfashionable end of the Western Spiral Arm of the Galaxy lies a small unregarded yellow sun…

I love Bash tab completion, and I want it for the command I am writing, so it can automatically complete parts of the command line when I run my program. Code Here is the script (install-bash-completion) I wrote to set it up (no need to be root – it in…

I am loving writing code in Rust. So many things about the language and its ecosystem feel so right*. * For example: ownership of objects, expressive type system, compile to native, offline API docs, immutability, high quality libraries. One of the thi…

Got a $20 voucher code for a review of a Rock Pi S SBC. Although the cost of the board is only $13.90, with shipping at just over $8, it’s a bit over $22 in total. When the board arrived, I did actually wonder if shipping could have been made a bit mor…

Got a $20 voucher code for a review of a Rock Pi S SBC. Although the cost of the board is only $13.90, with shipping at just over $8, it’s a bit over $22 in total. When the board arrived, I did actually wonder if shipping could have been made a bit mor…

I tried to describe the main ideas that will help you write decent React code. Maybe it will help you understand the docs a bit more when you read them… Slides: React Concepts slides

I have not found an automated way to generate a nice PDF from some slides written in HTML – if you know of one please add a comment! In the meantime, if you create slides using my HTML Slides template, then you can make a decent-ish-looking PDF like th…

The Software Freedom Conservancy helps Free/Open Source software projects by providing infrastructure, financial structures, and legal help. It is a not-for-profit organisation that is dedicated to software freedom, something that I think is an importa…

What it was like to write a snake game in KotlinJS: Slides: Snake in KotlinJS slides Code: github.com/andybalaam/snake

At my job we have done a great deal of work to remove Guice from our codebase. Here I try to explain why we did that, and try to apply my reasoning to dependency injection frameworks in general. Slides: Dependency Injection frameworks: reasons to avo…

Managed to get kmscube running on my Orange Pi PC with a mainline Linux 5.3 kernel and an updated mesa package from Ubuntu’s ubuntu-x-swat PPA. The amazing thing is that it’s all just mainline now, no board-specific patches needed. Interestingly, a Ras…

Managed to get kmscube running on my Orange Pi PC with a mainline Linux 5.3 kernel and an updated mesa package from Ubuntu’s ubuntu-x-swat PPA. The amazing thing is that it’s all just mainline now, no board-specific patches needed. Interestingly, a Ras…

This week we did a coding workshop exercise: 2 teams implemented the different sides of the SMPP protocol (without speaking to each other) and this morning we tried out connecting them together. We successfully sent a message and received an acknowledg…

I wrote a book about about genetic algorithms and machine learning. You can buy it here. Apart from genetic algorithms and other aspects of machine learning, it includes some swarm algorithms. Where a genetic algorithm mixes up potential solu…

I wrote a book about about genetic algorithms and machine learning. You can buy it here. Apart from genetic algorithms and other aspects of machine learning, it includes some swarm algorithms. Where a genetic algorithm mixes up potential solu…

The title might read a little like click-bait, and there are certainly some nuances and qualifications here. But, hey! That’s what the article is for. Those that know me know that I have been a practitioner of, and advocate for, TDD in C++ for many …

The title might read a little like click-bait, and there are certainly some nuances and qualifications here. But, hey! That’s what the article is for. Those that know me know that I have been a practitioner of, and advocate for, TDD in C++ for many …

I asked twitter who is using decision trees and what for. Most were using them, unsurprisingly, to make decisions. It wasn’t always clear how the trees themselves were built. If you are armed with data, so that each row has some features and a categor…

I asked twitter who is using decision trees and what for. Most were using them, unsurprisingly, to make decisions. It wasn’t always clear how the trees themselves were built. If you are armed with data, so that each row has some features and a categor…

To build a “fat” Jar of your Java or Kotlin project that contains all the dependencies within a single file, you can use the shadow Gradle plugin. I found it hard to find clear documentation on how it works using the Gradle Kotlin DSL (with a build.gra…

Quick quiz! Given the following: Which overload gets called by the following? Alternatives: f(unsigned int) f(int) f(char) No-one knows the type of char + char If you answered 4), congratulations! And if you answered 2), maybe you tried the code on your own computer? Most people will get f(int) when they try this code, but … Continue reading No-one knows the type of char + char →

Everyone knows attempting to figure out what’s happening by resorting to print statements is desperation. Everyone knows you should use TDD, BDD or some xDD to write code well, don’t they? I am desperate. I suggest PDD, print driven development is slow…

Everyone knows attempting to figure out what’s happening by resorting to print statements is desperation. Everyone knows you should use TDD, BDD or some xDD to write code well, don’t they? I am desperate. I suggest PDD, print driven development is slow…

Our mission: to create a self-signed certificate for an Apache web server that allows us to connect to it over HTTPS (SSL/TLS) from a Java program. The tricky bit for me was generating a certificate that contains Subject Alternative Names for my server…

Here is the live version of my talk designed to help you advocate for adopting Kotlin:

Here is the talk CB Bailey and I did at ACCU Conference 2019. This was the first talk I have done with someone else, and I really enjoyed it:

People at work suggested Kotlin was “just syntactic sugar”, so I set out to explain how Kotlin can really make better code, and here is the result: Slides: Examples of Kotlin making your Java code better slides

Slightly jokey video about what a Monad is, but with a genuine explanation, all in just about 5 minutes. First given as a lightning talk at the ACCU Conference in 2019. Slides: What is a Monad? Slides

To spin up a temporary environment with a different Java version without touching your real environment, try this Docker command: docker run -i -t –mount “type=bind,src=$PWD,dst=/code” openjdk:11-jdk bash (Change “11-jdk” to the version you want as li…

My Outdoor Maps app for Samsung Gear/Galaxy watches has finally been approved in the Galaxy Store.

My Outdoor Maps app for Samsung Gear/Galaxy watches has finally been approved in the Galaxy Store.

The ACCU conference happened in Bristol again this year. For my first time ever, I was at a workshop. In fact, I ran a work shop with Chris Simons. We talked about Evolutionary Algorithms in practice. We gave a 90 minute talk later in the week, using t…

The ACCU conference happened in Bristol again this year. For my first time ever, I was at a workshop. In fact, I ran a work shop with Chris Simons. We talked about Evolutionary Algorithms in practice. We gave a 90 minute talk later in the week, using t…

If you’d like to help promote Rabbit Escape, my free software Android/PC game, how about a t-shirt? Use the link below to design your shirt: Rabbit Escape t-shirt Note: there’s no profit in this for us – it’s just for promotion. If you’d like to contr…

When we want to do something later in our Java code, we often turn to the ScheduledExecutorService. This class has a method called schedule(), and we can pass it some code to be run later like this: ScheduledExecutorService executor = Executors.new…

HOWTO: celebrate finishing a project. If you are reading this you might have noticed that the Riverblade website has undergone a bit of a redesign. This is something we’ve been working on for a little while in the background, and we think it’s probabl…

HOWTO: celebrate finishing a project. If you are reading this you might have noticed that the Riverblade website has undergone a bit of a redesign. This is something we’ve been working on for a little while in the background, and we think it’s probabl…

ACCU is an organisation for programmers. Its original focus was C and C++, but now members use a variety of languages, talk about testing and process and how to keep learning. ACCU holds an annual conference in the UK, attended by people from around th…

ACCU is an organisation for programmers. Its original focus was C and C++, but now members use a variety of languages, talk about testing and process and how to keep learning. ACCU holds an annual conference in the UK, attended by people from around th…

The newest feature of Rabbit Escape, water, has been brewing a long time, but we now think it’s ready: Water can flow, it can put out fires, and it can drown rabbits. Rabbots seem to be immune though… Check out the 20 new levels we have released! (T…

Here’s a little script I wrote to avoid copy-pasting the ffmpeg command from superuser every time I needed it. It converts a video to a GIF file by pre-calculating a good palette, then using that palette. Usage: ./to_gif input.mp4 output.gif The file t…

In an insane world, Gradle sometimes seems like the sanest choice for building a Java or Kotlin project. But what on Earth does all the stuff inside build.gradle actually mean? And when does my code run? And how do you make a task? And how do you persu…

I found something difficult in Python, which was a bit of a first, so I wrote a whole blog series about it, and now a whole video: Slides: Python Async Basics slides Blog posts: asyncio basics, large numbers in parallel, parallel HTTP requests, addin…

I attended nor(DEV):con, a tech conference in Norwich, last week. I gave a 45 minute talk which I called “Code your way out of a paper bag”. A majority of my recent talks involve getting out of, and once into, a paper bag. I’ve used this as a vehicle…

I attended nor(DEV):con, a tech conference in Norwich, last week. I gave a 45 minute talk which I called “Code your way out of a paper bag”. A majority of my recent talks involve getting out of, and once into, a paper bag. I’ve used this as a vehicle…

Place the following in a command file, run it within your repo: #!/bin/sh git filter-branch –env-filter ‘ an=”$GIT_AUTHOR_NAME” am=”$GIT_AUTHOR_EMAIL” cn=”$GIT_COMMITTER_NAME” cm=”$GIT_COMMITTER_EMAIL” if [ “$GIT_AUTHOR_EMAIL” = “timp@paneris.o…

Place the following in a command file, run it within your repo: #!/bin/sh git filter-branch –env-filter ‘ an=”$GIT_AUTHOR_NAME” am=”$GIT_AUTHOR_EMAIL” cn=”$GIT_COMMITTER_NAME” cm=”$GIT_COMMITTER_EMAIL” if [ “$GIT_AUTHOR_EMAIL” = “timp@paneris.o…

I’ve been getting very excited about keybase.io recently, not least because it offers secure conversation, and you can have bots. I wrote a quick bot to simulate Arnold Schwarzenegger which I thought I’d share to demonstrate how easy it is. It is based…

Series: operations, images, opacity Not because I was enjoying it, I seemed compelled to continue my quest to understand the performance of various Java 2D drawing operations. I’m hoping to make my game Rabbit Escape faster, especially on the Raspberry…

Series: operations, images, opacity In my previous post I examined the performance of various drawing operations in Java 2D rendering. Here I look at some specifics around rendering images, with an eye to finding optimisations I can apply to my game Ra…

CppOnSea 2019 Phil Nash organised a new conference, CppOnSea, this year. I was lucky enough to be accepted to speak, so attended to two conference days, but not the workshops. There were three tracks, along with a beginners track, run by Tri…

CppOnSea 2019 Phil Nash organised a new conference, CppOnSea, this year. I was lucky enough to be accepted to speak, so attended to two conference days, but not the workshops. There were three tracks, along with a beginners track, run by Tri…

Series: operations, images, opacity I want to remodel the desktop UI of my game Rabbit Escape to be more convenient and nicer looking, so I took a new look at game-loop-style graphics rendering onto a canvas in a Java 2D (Swing) UI. For more on images,…

Most programmers I know are familiar with xkcd, the webcomic of romance, sarcasm, math, and language. In order to create diagrams for my machine learning book, I wanted a way to create something I could have fun with. I discovered that Pytho…

Most programmers I know are familiar with xkcd, the webcomic of romance, sarcasm, math, and language. In order to create diagrams for my machine learning book, I wanted a way to create something I could have fun with. I discovered that Pytho…

It was a pleasure to go to the London Python Meetup organised by @python_london. There were plenty of friendly people and interesting conversations. I gave a talk “Making 100 million requests with Python aiohttp” (slides, Blog post) explaining the basi…