I spotted today on reddit an article from O'Reilly Radar titled
Questioning Functional Programming. It's based on a programming contest in which more teams used non-functional languages than functional ones.
[The competition is] notable for two things: the fiendish complexity of the problem and the absence of functional programming languages in the final results. Top place went to a C++ program, with a Perl team right behind in second. In third place was "Team Celestial Badger" using OCaml and C++. In all there were 81 teams using C++, 67 using C, 66 using Haskell, 64 using Python, 52 using OCaml, 48 with Java, and 35 with Perl. Only 4 tried Erlang (the same number as used Delphi).
According to the report from the competition:
...As far as functional programming is concerned, we must conclude that functional languages didn’t fare too well this year (although in the Top 15 there were five users of OCaml and three of Haskell). Better luck next year!
There were 421 teams, of which 122 used functional languages -- about 29% (which ought to be much higher than their rate of adoption by the industry). Still, over 50% of the top 15 places were won by the teams that used functional languages. It looks like good performance to me.
It says to me that we're still in the early days of widespread adoption of functional programming.
I don't think this is what it says. Functional programming languages are obviously less popular than imperative ones. Maybe functional languages will never be as widespread as imperative languages. However, this competition is just a competition. I doubt it says much about language adoption by the industry now or in the future. (By the way, has anyone heard of Ruby? :) ) If anything, this competition suggests that functional programming languages are quite widespread, given their high rate of adoption by the contestants.
Like Ruby, which had tiny uptake until Rails and 37 Signals boosted it into the stratosphere, functional programming languages lack a reason to use them.
If Ruby lacked a reason to be used before 37 Signals, why did DHH use it to create Rails? He could have stuck with PHP. The reason to use Ruby did exist, even if fewer people knew about it.
"Functional programming languages lack a reason to use them." I don't think that great concurrency, scalability, fault tolerance, distributed programming, hot code swapping, Mnesia,
Yaws, and the rest are useless.
(In fact, Amazon has made Erlang much less useless today by
announcing the new 4-core and 8-core options for EC2 instance. I can't wait to get my hands on those :) )
Even those who advocate them [functional languages] aren't comfortable enough with them to push on with them in the face of hard problems.
The teams that were comfortable with functional languages did push on them in the face of hard problems: those teams used functional languages in the contest. They took 8 of the top 15 places, too.
I must say that I disagree with the conclusions of the article.
I'll end this posting with a relevant
message from the Erlang-questions mailing list yesterday:
> Hi.
> Recently, I have been trying to learn a language other than Java.
> Erlang seems to be ready for the prime time (used in the commercial world).
> On the other side, OCaml seems to be a cool and capable language.
> I want to learn something useful and fun.
> Tell what do you think ?
> (if you are Erlang die-hard, please put this aside ;))
>
When I was evaluating Python alternatives for building the core
technology behind MochiAds I tried out a bunch of languages and Erlang
was the only one that was easy for me to learn and had the right
balance of features, performance, and reliability. A year later we
have about 16 machines running 80 Erlang nodes powering about 16
different "components" of our infrastructure and 4 people working on
it at the moment (originally it was just me). It worked out so well
that we rewrote the server component of our MochiBot service in Erlang
and we've been using it to build lots of internal tools such as our
monitoring software, our single sign-on service, etc. as well. None of
us had previous Erlang experience, but we're all very comfortable with
it now.
After about a year with Erlang, I'm not sure I could part with hot
code loading, light-weight processes, and multiplexed socket IO for
writing servers. Also, Mnesia has been really useful to us to
temporarily store "real-time" data (ram_copies) so that we don't have
to make users wait for it to get batched into the SQL databases. The
distribution stuff mostly Just Works once you figure out how to set it
up (though we did have one bad experience with a network partition due
to a switch acting up, it was recoverable manually).
O'Caml is a useful language too, but for writing a network app I can't
really imagine going with anything but Erlang if you're looking for
redundancy and scale. Unless you want to write your own half-baked
Erlang-like system before even trying to solve something a little
closer to your actual problem domain.
-bob
It looks like functional programming must be good for something.
