Why OO Sucks

(by Joe Armstrong)

When I was first introduced to the idea of OOP I was skeptical but didn’t know why – it just felt “wrong”. After its introduction OOP became very popular (I will explain why later) and criticising OOP was rather like “swearing in church”. OOness became something that every respectable language just had to have.

As Erlang became popular we were often asked “Is Erlang OO” – well, of course the true answer was “No of course not” – but we didn’t to say this out loud – so we invented a serious of ingenious ways of answering the question that were designed to give the impression that Erlang was (sort of) OO (If you waved your hands a lot) but not really (If you listened to what we actually said, and read the small print carefully).

At this point I am reminded of the keynote speech of the then boss of IBM in France who addressed the audience at the 7th IEEE Logic programming conference in Paris. IBM prolog had added a lot of OO extensions, when asked why he replied:

“Our customers wanted OO prolog so we made OO prolog”

What is the exact difference between parallel and concurrent programming ?

Parallelism is about speeding things up, whereas concurrency is about dealing with simultaneity or nondeterminism.

When we talk about parallel programming, typically we are interested in reducing execution times by taking advantage of hardware’s ability to do more than one thing at once, whether by vectorization, instruction-level parallelism (superscalar architectures), or multiprocessing (multiple cores or processors). Parallel programming does not imply a particular programming model, and many techniques and languages for parallel programming are at various stages of development or adoption.