software development – Page 15 – Kev's Development Toolbox

August 18, 2015

Uncle Bob: “Make the Magic Go Away” – why you should learn some Assembly

I’ve been spending some spare time learning some ARM Assembly (and sharing from of my experiences here, here and here).

In the early 90s at college I did a module on 68000 Assembly on the Atari ST, but I haven’t done any since. I remember being amazed at how complicated and it was to implement even the most simplest of code, since you’re dealing with a very limited set of instructions, using instructions that the CPU itself understands. At the same time though you gained an insight into what goes on under the covers, how the computer itself works – how the CPU’s registers are used, and how data is transferred from registers to memory and vice versa. It’s computing at it’s most elemental level, you’re working with the bare metal hardware.

Since I’ve also recently been playing around with random stuff on the Raspberry Pi, I thought I’d take a look at the ARM CPU and learn some ARM Assembly. I felt a need to get back to basics and learn about the architecture of ARM CPUs and what makes them tick. As much as this sounds pretty hardcode and crazy, ARM CPUs are showing up pretty much everywhere and you probably don’t even know it. There’s a good chance at least one if not more of you mobile devices you currently and have owned over the past few years has been powered by an ARM CPU. So given the memory and CPU contraints of small form factor devices, and also IoT type devices, it’s not completely off the wall to be interested in learning some ARM Assembly.

Anyway, back to my original point. If you want to understand what makes a computer tick (literally), you can’t go far wrong by learning some Assembly. You’ll get a far better understanding of what goes on under the covers, and a new appreciation of just how much abstraction there is in today’s high level languages (Java, C#, Objective-C etc) – how much they do for you without you even really have to know what’s going on under the covers. But if you really want to get a deeper understanding, you lift the hood/bonnet and start poking around in the engine, right?

It surprised me when I came across this post by Uncle Bob recently:

http://blog.8thlight.com/uncle-bob/2015/08/06/let-the-magic-die.html

Bob comments on the continual search within the industry to find the perfect language or library. We’re continually re-inventing languages and frameworks, but there’s really nothing revolutionary different being ‘invented’ – they’re all solving the same problems, and not really offering anything new. Bob even goes as far to say there really hasn’t been anything new in computer languages for 30 years.

The unusual thing is that we seem to get caught up in the promise that maybe the next big language or framework ‘solves all problems’ and does it better than all other languages and frameworks before, but there’s still really nothing new.

Bob’s point:

But there is no magic. There are just ones and zeros being manipulated at extraordinary speeds by an absurdly simple machine. And that machine needs discrete and detailed instructions; that we are obliged to write for it.

And continues:

I think people should learn an assembly language as early as possible. I don’t expect them to use that assembler for very long because working in assembly language is slow and painful (and joyous!). My goal in advocating that everyone learn such a language is to make sure that the magic is destroyed.

And here’s it is, the reason why you should learn Assembler:

If you’ve never worked in machine language, it’s almost impossible for you to really understand what’s going on. If you program in Java, or C#, or C++, or even C, there is magic. But after you have written some machine language, the magic goes away. You realize that you could write a C compiler in machine language. You realize that you could write a JVM, a C++ compiler, a Ruby interpreter. It would take a bit of time and effort. But you could do it. The magic is gone.

I don’t know exactly what prompted me recently to start learning Assembler, but these comments from Uncle Bob resonated with me. If you don’t know how a computer works, how do you expect to understand what is going on when you develop code to run on it?

So there you go. Bob said it. Go learn Assembler. Maybe you’ll learn something.

August 1, 2015

The Unavoidable Compromise of Business Driven Development

Given enough money, time, experience, technical experience and creative input, time has shown as an industry we can build awesome things. Unless you’re working on a self-funded project with unlimited supplies of cash and time, it’s unlikely that most of us will ever have the experience of working with minimal or no resource constraints.

Software development in ‘the real world’ is really no different from any other business, and the concept of the Triple Constraint has been well understood in Project Management for some same. This describes the inter-relationship between 3 attributes of:

schedule
scope
cost

and how they interact to affect quality of the final product. At a high level, it’s generally understood that you can have ‘any two’ of these, but it’s impossible to have all three at the same time. Each of these attributes translates to desirable qualities of:

fast (deliver the product in less time)
good (include all desired features)
cheap (deliver at low cost)

So, you can have fast and good but it won’t be cheap, or you can have fast and cheap but it won’t meet all your requirements (some features will have to be left out).

So back to the original topic. How is software development a compromise? Invariably because your client or your company wants all these things: “we want it developed in an impossibly short amount of time (get it ready for tomorrow), we want this massive list of features (and no, we’re not prepared to leave any out), and oh by the way, we only have enough money to pay for 1 developer to work for 8 hours”.

While technology can go some way to helping produce more for less (code generation etc), the reality is that software development in the real world is not a technical problem. It is a business problem of negotiating contracts and managing expectations. For the technologist, this is the continual struggle – pretty much everything you work on will be under less than ideal conditions.

Business Driven Development (BDD). Welcome to the Real World.

May 26, 2015

Sometimes the simplest solutions are the best solutions

How many times have you seen or written code like this (in any language):

[code]
if(someFlag){
someFlag = false;
}
else{
someFlag = true;
}
[/code]

I’ve written code myself like this many times, and seen it in many places too. Usually for toggling display of some content: “if it’s hidden, show it; otherwise, hide it”.

Recently I’ve been spending a lot of time learning and coding an app using AngularJS and I keep seeing this pattern repeatedly in many code examples:

[code]

someFlag = !someFlag;

[/code]

When I first saw a statement like this it took me a couple of seconds to understand the purpose, but then when it clicked I laughed out loud in one of those ‘ahah!’ moments, as the outcome of this code is exactly the same as the code above.

When we translate design to code, sometimes thinking in logical, procedural steps hurts the ability to translate to code that best uses the features of the language or platform that you are running on. Sometimes the simplest solutions really are the best solutions, although maybe it takes a different thought process to get there.

March 21, 2012

Ted Neward: Junior developers need to unlearn what they think they know

This is a great commentary by Ted Neward on a blog post on the pitfalls of junior developers: the importance of asking questions, and realizing as a junior developer (and we all have areas where we are junior developers, regardless of industry experience), you don’t know everything.