Erlang First Impressions

I attended an Erlang training Saturday January 22, 2011 taught by Kevin Smith (twitter) of much Erlang fame. I first met him last year when he did an Riak presentation to the Charlotte Ruby group. Anyway he is an excellent instructor (maybe a couple to many emacs plugs ;) and it was an amazing class. It was so good I feel like my brain is a little hung over from the experience (or maybe the beer we had after). In an effort to try to medicate I figured I would write up my thoughts.

The good:

• Concurrency #1 implementation detail
• Runtime reload of code
• Shell
• Atoms
• Pattern matching parameter over loading / conditional methods
• Message passing as core part of language is easy and wonderful
• Monitor / Subervisor to restart services that fail

The bad:

• Strings (this is pretty bad since it is the most used datatype)
• Contextual termination ",", ";", "." can all terminate a line / function (I almost like it but don't)
• Syntax is 30 years old and has not aged well
• Immutable types

Erlang make concurrency very easy in some ways by making a lot of other programming very difficult. Writing simple service oriented things like key/values stores or simple, reliable CRUD task it is perfect for. Where as for algorithms, string processing and other complex operations it is a poor solution for. Unfortunately I don't have many concurrent distributed problems where the difficult part is getting the concurrency right. However I now understand why databases like CouchDB and Riak are written in erlang. At the moment I am not writing a lot of simple services however I can see how it would be helpful in the future for simple services.