Erlang is WTF?

As you know from a recent post, I am not into language bashing but I recently came across a witty one liner that sort of resonated with me: "C is fast, Ruby is beautiful and Erlang is WTF?" I might substitute a functional language (like Lisp or Haskel for Ruby) but the basic message is a valid one. Erlang as some cool ideas but they are packaged into a slow and rather ugly (syntactically) implementation.

How do you know when you have mastered a new programming language

This is a minor continuation of my thoughts from The Law of the Excluded Middle does not apply to Programming Languages.

One sure sign that you have mastered a language is when you can create a fairly comprehensive list about what sucks about the language (while simultaneously appreciating why some of this suckiness is a necessary evil).

When you first meet a new language that floats your boat, there is a tendency is to fall in love. This happened to me not too long ago with Erlang. You think, "This language is great. Such and such is so hard to do in Language X and look how easy it is in Language Y.

Well, much like in the real world of human relationships you don't really know what love means until you get married! When you get married to a language (commit to developing a multi-year non-trivial system in it) then your love is surely tested. You learn about the languages warts and its tendency to leave its socks outside the hamper, squeeze the tooth paste from the top and leave the toilet seat in an inconvenient position!

If you still love the language with its warts and all, then you have some of the necessary (but not necessarily sufficient) hallmarks of a master. Either that, or you ave a really good therapist.

p.s. Erlang and I broke up but we are still friends! On a happier note, my long term mistress (Mathematica) and I are really making sparks fly! Hope C++ doesn't catch us.

Communicating Sequential Processes

My recent interest in Erlang has motivated me to reread C.A.R. Hoare's classic Communicating Sequential Processes . If you are interested in software development and concurrency then I implore you to read (and re-read) this important work. If you won't take my word for it then consider the words of Edsger W. Dijkstra.

The most profound reason [the manuscript was eagerly awaited] , however, was keenly felt by those who had seen earlier drafts of his manuscript, which shed with surprising clarity new light on what computing science could—or even should—be. To say or feel that the computing scientist’s main challenge is not to get confused by
the complexities of his own making is one thing; it is quite a different
matter to discover and show how a strict adherence to the tangible and quite
explicit elegance of a few mathematical laws can achieve this lofty goal. It
is here that we, the grateful readers, reap to my taste the greatest benefits
from the scientific wisdom, the notational intrepidity, and the manipulative
agility of Charles Antony Richard Hoare.

Erlang Über Alles

Ralph Johnson, from Gang of Four Fame, has some nice things to say about Erlang.

Er, which lang to use?

I have been fretting over which programming language to use to build my first Semantic Vector Space and Wisdi implementation. This was a big decision. On one hand, I was tempted to uses C++ because am an expert in it and have become enamored with modern C++ development techniques that are exemplified by the STL and Boost libraries. I also knew I can make the code smoking fast. On the other hand, I knew I would wrestle with all the usual issues that C++ developers wrestle with (pointer corruption, memory management, increasing build times) and they would distract from an effort that is still much more R than D.

A compromise seemed to be Java 5 (or 6). Generics removed some of my disdain for the language. However, generics are not C++ templates and sometimes having half of something can be more painful than having none.

I also (very briefly) considered Ruby, Python and even Mathematica but none of these would do for reason that are both logical and admittedly emotional.

This past Wednesday a received a copy, fresh of the press, of Programming Erlang: Software for a Concurrent World by Joe Armstrong. That clinched it for me.

The great thing about Erlang is that I practically knew it already because many of the constructs related to list processing and pattern matching are similar or identical to two languages I am comfortable (Prolog and Mathematica). The second trait was that it is an very clean functional language and I always wanted to do a large development project in a functional language. Third, and unique for functional languages, it lets you go way down close to the metal and manipulate arbitrarily complex binary structures with out escaping to C. Fourth, you can escape to C. Fifth, and by far the most important, Erlang will scale due to its elegant concurrency model and it will do so with out all the typical headaches associated with writing concurrent code. And finally, I imagine the capability of hot swapping will be welcome when exposing ones creations to the world and getting that first bug report.

Now, Erlang is not perfect; no language is. It sacrifices type safety and does not have a good security model for distributed computing. However, when almost all your D is to drive R then these issues are less important.

So it begins this weekend. Me and Erlang are about to become quite intimate. Time to brew a big pot of coffee. See you on Monday.