Peter's Blog

Just commenting on things that interest me

Peter’s Programming Principles: Elegance

Programming is an art, not a science. Some people might baulk at the idea that it’s an art, but it is certainly a craft.

Bad programmers write bad code, great programmer write elegant code.

I have read a lot of code in my time. And some of it was so badly written that it was scary.

Conversely, it is a pleasure to read code that is so well-written that it is elegant.

Writing a program involves making dozens (perhaps hundreds) of decisions. It involves solving lots and lots of puzzles.  Solving puzzles is one of the great joys of programming. There always multiple ways to tackle each puzzle. And each decision is an opportunity to move towards elegance, or towards chaos.

I don’t think everyone can be a good programmer. I have worked with people who wrote chaotic code. This code was a nightmare to read, and a nightmare to maintain/enhance.

Some people have the gift of finding the elegance, and some do not. That’s what separates bad programmers, from good programmers, from great programmers.

In my opinion, a great programmer would not be happy just to get a program working. They would not be happy until the program is elegant.

I think it’s acceptable to write a small piece of inelegant code while you’re trying to get something working, or to understand it fully. But once you have that clear picture, you should always rewrite/refactor for elegance.

A simple example of the decisions which a programmer needs to make is when functionality should be delivered inline, when it should be moved out to a separate function/method, and when a new Class is needed.

Elegant code should be easy to read and understand. Badly written code can be a nightmare to understand!

First Example

I have a book called “Java Examples in a Nutshell” (written by David Flanagan) which I cannot throw out (even though it is dated – my edition was written in 1997) because the code is so elegant.

Second Example

This is a link to some Java code which implements the Asteroids game as a Java Applet (it was written a long time ago!)

It is a very faithful recreation of the original game and I think the code (although there is quite a lot of it) is very nicely written and very easy to read.

The main look contains the following:

updateShip();
updatePhotons();
updateUfo();
updateMissle();
updateAsteroids();
updateExplosions();

Makes sense right?!

Aside from the main Class, there is only one other one: “AsteroidsSprite”. This is used to manage all of the “vector graphics”-style objects.

The Class has a method called “isColliding” which takes one argument which is another AsteroidsSprite. So you can easily ask any AsteroidsSprite if it is colliding with any other AsteroidsSprite. Simple as that.

And there is a method called “explode” which takes an AsteroidsSprite as an argument. It creates a set of AsteroidsSprites, one for each line in the original object. And then those  AsteroidsSprite are added to an array called “explosions” and those lines move and fade as they would have in the original game.

In the hands of a less capable programmer than Mike Hall this could have been a real mess. But it’s not. It is elegant.

Conclusion

The different between a mediocre programmer and a great programmer is that the latter can make a series of decision which allow him/her to write elegant code.

 

Peter’s Programming Principles: Simplicity

KISS (or “Keep it Simple Stupid”) is a principle which was created in the 1960s apparently.

Certainly it was something we talked about when I started programming.

It is as true now as it was then.

Apparently Einstein said that ““Everything should be made as simple as possible, but no simpler.” He was a smart guy!

The trick in programming is to resist using something because it’s clever, or because it’s new, or because it’s trendy.

When something is simple, it easier to get right, it’s easier for others to understand, and it’s easier to maintain and enhance.

I have two stories to illustrate this: one new, and one very old.

First Story

The old one was when I was working in Shield Life and going to Trinity College in the evenings.

On my course I learned how you could create files where each record had a pointer to the next record (and optionally a pointer back to the previous record). So when you found the first record in a set, you would easily navigate to the others. And you could have another chain of free records which would could use when you needed to create a new record.

So we had a requirement for an “Outstanding Premium File” (OPF) which would store all of the premiums which made up an individual Direct Debit for the bank. Then if the Direct Debit was declined, you could work out which policies had not been paid so that you could take appropriate actions. I decided that this was a perfect use case for a file with record pointers.

I developed the program and it worked perfectly.

The problem was that, after I left the company, the team decided to re-develop the program using a more traditional approach which everyone could understand and maintain.

So I had ignored the KISS principle and I had developed something that other programmers did not like. I had been seduced by something that seemed to be very clever.

Story Two

The second story is recent. We were developing a solution using SharePoint Online, SPFx, Azure, etc. and the architect and developers decided to use a Term Set in SharePoint to hold data which could have been held in a lookup list.

I could not understand the purpose of using a Term Set for this. Term Sets have an important role to play in some circumstances. But to me it looked like complete overkill for a lookup field.

And it turned out that it introduced a number of unnecessary complexities:

  • We needed to have separate term sets for test and production. Using lists, it would have been as simple as having two sites and independent lists in each.
  • We had to add values to lists using PowerShell and these scripts were made more complex and more troublesome because they had to populate the term sets
  • The client wanted to export the data to Excel. We used the native export at first. But the term set columns were weird when exported to Excel. In the end, we did a custom export.

Conclusion

Einstein was right: it’s best to keep everything as simple as possible, but no simpler

 

Peter’s Programming Principles

I have been developing software for a long time. And over those years, I have come up with an approach to programming and some basic principles.

These are now part of my “guy feeling” when I’m developing something new. But in the coming posts I am going to try to isolate, examine and document them.

I’m calling this series “Peter’s programming principles”. There are a couple of things to say about this:

  • I could not resist the alliteration!
  • I’m not sure when exactly “programming” became “software development”, when “programmers” became “software engineers”, and when “programs” became applications/apps. But I think the old names were just as good.

The principles are all high-level. They are about an approach. If I talk about a specific technology then it will only be to explain the principle.

The principles I am going to describe are:

  • Simplicity
  • Elegance
  • Shibumi
  • Sleep on it
  • Layering
  • Looping
  • Data-Driven

 

COVID-19 Sketch

Wanting to do something challenging and interesting on my IoT DevKit, I decided to do something with a COVID-19 theme (we have so little else to think about these days!).

My idea was simple: to get some statistics from the web and to display them on the built-in screen.

The first step was to choose a suitable API. I chose the “Novel COVID API“.

This API returns data in JSON format. So I need to choose a suitable library for parsing the data. I choose the ArduinoJSON library.

The next step was to decide how to present the data. The device only has a 4 line display with 16 characters per line. So I ended up creating a series of screens to show the data for each country, trying to group the data logically. Because the first line is a different colour, it was fairly obvious that I should reserve that for the country name.

The last step was to decide how to control the display. The device just has two buttons: A is on the left and B is on the right. I decided on the following:

  • You would press button A to move from one country to the next one
  • You would press button B to move from one screen to the next one
  • You would press the two buttons at the same time to go back to the API to get fresh data

To be honest, I am quite pleased with the way the sketch turned out. You can see a video of it in action below. In the video you can see me viewing data for Ireland, USA, UK and the world.

The data which is shown is correct for today: 17th May 2020.

You can access the code here.

MXChip IoT DevKit (AZ3166)

In late 2018 I attended an IoT training session in Microsoft here in Dublin. They gave us all a “DevKit” which can be used to experiment with IoT in conjunction with Microsoft Azure. The device was jointly developed by MXCHIP and Microsoft.

The device is like an Arduino except that it is packed with sensors and also has:

  • A small (4×16) OLED screen
  • A headphone socket
  • An Infrared emitter
  • Built-in Wi-Fi.

Here’s a diagram showing the various components:

And here is a picture of my device:

Because this device has so much built-in capability, I always intended to develop something for it.

And in my next post I will describe my first project.

Arduino Uno

I got my first computer in the 1970s (an Apple ][) and my second in the 1980s (an Atari 800).

I always had an interest in getting my computer to interface with hardware devices but I never really did anything about it.

In 2011 I came across the Arduino platform and I finally had a chance to use a device which straddled the gap between software and hardware. I bought a book called “Arduino Cookbook” and I learned all about “sketches” (software) and “shields” (hardware).

Later that year I bought the “ARDX arduino experimentation kit“.

To be honest, I spent a lot more time reading the book than I did playing with the kit!

In July 2012 I did bring both on a holiday to Kenmare and I managed to create a fairly interesting light display with 8 LEDs.

Included below is a video from that time showing how it worked.

I planned to add a potentiometer to be able to control the speed of the sequences but I don’t think I ever got that working.

Coronavirus, Leo Varadkar and Sarah Connor

So Coronavirus (COVID-19) has been dominating our lives for weeks and week now.

But we do have some control over what happens. We can choose to stay home. We can choose to wash our hands. We can choose to do social distancing.

And we are lucky (unlike some other countries) to have good leadership at this time of crisis. Leo Varadkar is doing a great job. So is Simon Harris. So is Tony Holohan. So are our front-line workers.

But my admiration for Leo Varadkar went up a few notches back in March when he used a line from the Terminator movies during a very serious speech. He quoted the line: “There is no fate but what we make for ourselves”.

At first I was astonished – I thought I must have misheard.

But no – he really did say it. Fair play to him.

Here are the speeches by Leo, Simon and Tony (the line is at 6:14):

Another thing to hate about The Rise of Skywalker

In a recent post I mentioned three things that I hate about The Risable of Skywalker.

Well here is a fourth thing which I missed completely.

Apparently, TRoS has the worst music of any Star Wars movie.

Now obviously John Willians is a genius, and his contribution to the success of Star Wars cannot be overstated.

But apparently something went wrong with TRoS (probably all of the re-shoots and re-edits) and the musical cues from the previous movies are messed up in this movie.

Here is the information from the expert on the subject:

Bruce Lee’s Death

I mentioned Bruce Lee in my last post.

My son (knowing that I am a huge Bruce Lee admirer) bought me the book “Bruce Lee: A Life” by Matthew Polly some time ago.

It’s a big book and I’m ashamed to say that I haven’t read it yet.

I did however manage to read an article by Matthew on history.com where he puts forward a new theory on the cause of Bruce’s death.

In relation to the official cause of death, the article states that “The autopsy had revealed the medical reason—cerebral edema (swelling of the brain)—but the coroner had no idea what had caused it”.

I the absence of an obvious cause, the government accepted a theory that the cause was a “severe allergic reaction to aspirin, or anaphylactic shock”.

Matthew Polly rejects this theory saying that “Lee was a hardcore martial artist who had taken aspirin most of his adult life without any side effects”.

He puts forward an alternative theory that Bruce died from heat stroke and associated this with the fact that “Several months before his death, Lee had an operation to remove the sweat glands from his armpits”.

It’s amazing that new theories about Bruce’s death are emerging 47 years after his death. But it’s a testament to the man (the legend) that people want to know.

Here’s an iconic picture of Bruce from Way of the Dragon:

 

 

Bruce Lee Watch from Casio

I mentioned my hero Bruce Lee in a recent post.

I mentioned Casio watches in a recent post.

This post brings those two topics together as it is about a Bruce Lee watch which has been released by Casio!

I wasn’t sure what I thought about this at first, but I have come to like the idea.

Here’s what you need to know:

  • The watch has a black and yellow colour theme based on Lee’s iconic outfit from Game of Death
  • Bruce Lee’s signature, the Chinese character for his nickname “dragon,” appears at the 3 o’clock position on the dial
  • Bruce’s tenet of “Using no way as a way, having no limitation as limitation” appears on the bezel and on the case in Chinese characters
  • The Jeet June Do symbol (based on Yin and Yang) also appears on the back
  • It’s designed to last with a titanium case and bezel (the bezel is also coated with diamond-like carbon to increase abrasion resistance) and the glass is sapphire crystal with non-reflective interior coating
  • It’s a solar-powered G-SHOCK with Bluetooth
  • It was released this year to celebrate a significant anniversary for Bruce (he would have been 80 on November 27th)
  • Only 300 were made (in Japan) and the RRP is $4,000

So if anyone is looking for something to buy me as a present…

This flashy video was made by Casio to promote the watch

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