Programming languages worth learning

Prelude

Programming languages have always been a passion of mine and through the years I’ve learnt quite a few of them. The first one was Pascal, some 13 years ago, and the last was Scala, just a couple of months ago.

Although the authors of many languages claim that the language they created is the greatest thing after hot water, this is rarely the case. Most of the “unique” features are not quite unique, and the truly unique stuff is often just useless. I don’t believe that there is a single greatest and unparallelled language, but I do believe that some languages are more valuable them others in term of both theory(the concepts around which they revolve) and practice(the chances of you landing a job with them or simply getting a task done).

In this blog post I’ll review the ten or so languages that I’ve found to be most enlightening/helpful for me over the years. I think that every professional software engineer should have at least a passing knowledge of them.

C

The C programming language has been around for about forty years now (it appeared in 1973). While it’s often viewed as a higher level assembly language today in the era of Java, .Net and Python, C remains the sole choice for doing serious system programming - writing drivers, all kinds of servers and virtual machines.

Learning C also give you an insight to the inner working of the computer, like memory management and native data types (based on a CPU’s registries).

The best way to get started with C hasn’t changed in the past 20+ years - just pick a copy of “The C Programming Language” by K&R.

Lisp

Lisp is worth learning for the profound enlightenment experience you will have when you finally get it; that experience will make you a better programmer for the rest of your days, even if you never actually use Lisp itself a lot.

– Eric S. Raymond, How to Become a Hacker

One of the oldest programming languages around - created in 1958 and still relevant today. Important for its unique code is data approach, advanced code generation facilities (macros) and the ability to develop software in incremental and interactive fashion.

Although many of the features that originally made it truly unique (like garbage collection, if expression, function objects) are now found in many modern languages, Lisp still offers some compelling alternatives for those interested to explore it.

These days Common Lisp is considered the canonical Lisp dialect - a multi-paradigm language with excellent support for imperative, functional and object-oriented programming. Another popular dialect is Scheme which is a simpler language focused mainly on functional programming and until recently was a popular choice for teaching introductory programming classes in many major US universities (recently it’s being displaced by Python).

You cannot start with a better introduction to Common Lisp than Peter Seibel’s “Practical Common Lisp”. If you fancy Scheme more take a look at the classic text “Structure and Interpretation of Computer Programs”. A good source of exercises for aspiring Lisp programmers are the “99 Lisp Problems”.

Java

Let’s face it - if you’re in the market for jobs a third of them are about Java EE or Android development (the other two thirds are probably related to PHP and .NET). The language is not quite elegant, but the platform is truly magnificent. Although there are many other languages targeting the JVM (Scala, Groovy, Clojure, JRuby, Jython - just to name a few) Java is still predominant by a wide margin and this is unlikely to change soon. It’s actually the most popular programming language in the world.

I’ve taught a couple of introductory Java programming courses (in Bulgarian), but I’d recommend the “Core Java” book over my lectures any day of the week.

Haskell

Functional programming has been gaining popularity in recent years with the rise of parallel computers, and of the pure functional programming languages Haskell is probably the closest to the mainstream. It features great ideas like type inference, lazy evaluation, monads, pattern matching. As with Lisp many of the features of Haskell can be found in more impure packages(like Scala and Clojure), but Haskell is still the top pure functional language in my humble opinion.

There are great free Haskell learning resources on-line like “Learn you a Haskell for great good” and “Real world Haskell”

Perl

Once the undisputed king of the Internet Perl has recently fallen down from grace in its battle with the newer generation of dynamic languages like PHP, Ruby and Python. While I wouldn’t advise anyone to start writing Web or Enterprise apps with Perl it’s still the best language for writing administration and helper scripts with minimum fuss and maximum developer throughput. It features the greatest support for text processing ever and an extremely flexible (albeit a bit of confusing) syntax.

Perl CPAN is probably the largest collection of third party libraries for a single language ever assembled.

Pick up a copy of “Learning Perl” or just browse the excellent perldoc and start coding in Perl right away.

Clojure

Clojure is a Lisp dialect with an unique support for parallel and concurrent programming and runs on top of the venerable JVM. If you’re looking to do some serious parallel programming look no further. Other than that you’ll find in Clojure a superb collection of functional data structures, pervasive use of laziness, higher order functions and tail-call optimizations, and some rather novel ideas on the topics of state and identity. Clojure also cleans up a bit the traditional Lisp syntax (read this as Clojure has fewer parentheses than say Common Lisp).

To get started I recommend you to watch the free Clojure screencasts on YouTube.

Prolog

The most famous language from the logic programming family. Solving a problem like a sudoku puzzle in Prolog will be an eye opening experience for any developer. While it’s unlikely that you’ll ever use it practice the ideas found in it, Prolog will truly expand your thinking horizons.

A good starting point in your journey to Prolog will be “Learn Prolog Now”. You may do a follow up with the collection of programming puzzles “Prolog problems”.

Ruby

A pure object oriented dynamic scripting language with a very nice support for metaprogramming. It has versions written in Java (JRuby) and .Net (IronRuby) which makes it easy to integrate it with any software for those popular platforms. The language became popular with the rise of the Ruby on Rails web framework, but it has many potential applications that don’t involve RoR or web development.

“Programming Ruby” and “The Ruby Programming Language” are two of the best introductory Ruby books around.

Python

A pure object oriented dynamic scripting language with a focus on simplicity, readability and maintainability. Popular for development of web applications, GUI applications and system administration utilities. Driven by the motto “There is only one way to do it” and the philosophy “It comes with battery included”. Python is Google’s darling and is widely used by the IT giant.

A nice free on-line book about Python is “Dive into Python 3”.

C#

The flagship language of the .NET platform. Similar in many aspects to Java C# is never-the-less ahead then Java in the innovations department - first to introduce concepts like Generics and Attributes to the mainstream programmers. It features some nice improvements over Java like properties, flexible namespaces and limited type inference.

The primary reason it’s included in this list, however, is simply the sheer amount of job openings for C## developers. In my home country (Bulgaria) about a third of all programming positions are C## related.

My favourite C# book happens to be “C# in Depth”. You might happen to enjoy it as well.

Scala

An interesting blend of pure object orientation and functional programming with some concurrency support baked in (actors). Of the current crop of JVM languages, next to Clojure, Scala looks most promising. It features an advanced static type system (more advanced than Haskell’s), state of the art Java integration, support for pattern matching, extractors and other functional goodness. If any language has a chance of displacing the Java programming language it must be Scala… Even the father of Java James Gosling acknowledged that if he decided to replace Java with another language it would be Scala.

Start your journey to Scala mastery with “Programming in Scala”.

JavaScript

We cannot conclude this whirlwind tour of notable programming languages without mentioning the King of the Web, the language that drove the Web 2.0 revolution - JavaScript. Although it has a terrible name (JavaScript shares nothing with Java), a questionable programming model built around mutating global variables, and prototype instead of class inheritance, it is supported virtually everywhere (most web browsers have built-in JavaScript interpreters) and any web developer will do well to learn some JavaScript.

Epilogue

We cannot be experts in ten or twenty programming languages - I’m certain of that. I do, however, believe that all the ideas and techniques that we discover in different programming languages will generally enrich our thinking and make us better software engineers in principle.

P.S. If you’re wondering why a certain “great” language X is not on the list keep in mind that this is my personal (and highly subjective) point of view on the subject. Who knows, in some dark and twisted place there may very well be people who consider BASIC a programming language masterpiece…