The first day was broken into two session, each in a tutorial style. For the first session I was in the Building Robust Servers Using Erlang presented by Martin Logan from Orbitz. This stumbled a bit at the beginning, I think Martin was hoping people would be more familiar with Erlang as a language so he could delve into how to build a robust server. It picked up in the end though and I think he successfully drove his message home. The people I talked to after the session expected it to be a basic description on how to write Erlang but were impressed by the power of OTP, especially the supervisor model. A few people remarked that Erlang seemed great for anything that needed to be long running, so I think Martin was successful.
I jumped between all of the presentations in the second session.
- F# - This was interesting, I hadn't seen F# much before. The presenter was teaching it through an ant simulation and had a contest with prizes.
- Camlp4 and Template Haskell - I was a bit let down by what I saw of this one. It didn't seem like the presenters really gave a good introduction to templating languages. They presented a problem and let everyone work on it and would go around answering any questions. I wish my laptop battery was working so I could have taken a shot at playing with Camlp4. To their credit they were very helpful when asked but the initial presentation seemed lacking to me. Perhaps it was just too far over my head at this time.
- Scala and Lift - This was the presentation that I had the least interest in but I think was the most well done. David's presentation was interactive and had no slides. He simply wrote code with you and explained what it did and I think that worked well. Everyone I talked to after seemed impressed by what Lift was capable of accomplishing so easily.
Day 2 was all talks done in serial. I enjoyed most of the talks quite a bit. Yaron Minksy from Jane Street started out by saying something I think was important and easy to forget if you are heavily in the FP community. Despite the clear progress FP seems to be making (F# in Visual Studio, Real World Haskell, FP's in several big companies), we really aren't growing like we'd like to think. For most people management either says no to a functional language or it has to be snuck in through the back door. That is why they chose the keynote to be about F#. Microsoft including it in Visual Studio is a big leap and probably the biggest news in terms of FP going mainstream. But is it enough? We'll find out in the coming years.
- F# - This was the keynote presented by Luke Hoban from Microsoft and he painted a really great picture of F#. His talk spanned how they introduce F# to non-functional programmers, a demo of F#, and some experiences in productizing it. The integration with Visual Studio was topnotch. Luke showed off how easy it is to create a GUI, handle events, and run asynchronous code. It almost made me wish I was running Windows, it looked so nice. The power of F#, to me, was making GUIs. The language looked like it had to be weakened a bit in order to successfully exist in the .Net ecosystem but if I ever find myself working on Windows I will gladly use F#. How much will F# be adopted by mainstream programmers? Who knows, I'm hoping quite a bit though.
- Scaling Scala at Twitter - I knew Twitter used Scala but I did not realize they were such a large Scala shop. Scala was another language that seemed to have good representation at CUFP. I am still not sold on it but people seem to be doing great things with it. This talk was mostly about experiences in building the geolocation in Twitter. It was impressive that geolocation was built very quickly by two engineers who had no Scala or Java experience. There were two takeaways from this talk. The first is that the data center is the new computer. When you are designing a distributed application you really need to think differently about it than you would a non distributed application. This should not be a surprise if you really think about it but the emphasis seemed to be that in many cases people don't realize there is a difference. The second was that we should be honest about GC and realize it is a leaky abstraction. It would be nice if the application could get information back from the GC. The application really knows best how to handle working under heavy load and it would be nice if it could query the GC to figure out what kind of load it is under. I am not quite sure how much I buy the second one, couldn't the application monitor itself based on some metric relevant to its operations and modify its behavior based on that?
- Cryptol, a DSL for Cryptographic Algorithms - This was from the people at Galois. I don't know much about Galois other than dons works there and they do Haskell, but it looks like they get nice government contracts too. I had no idea how complex the world of cryptology is. I knew the algorithms were sophisticated but not the rest of it. Cryptol seems powerful but much of the talk was over my head.
- Naïveté vs. Experience - or, How We Thought We Could Use Scala and Clojure, and How We Actually Did - This talk was by Michael Fogus and my favorite. MIchael was entertaining and insightful. Most of this talk was about Scala and it included why they moved to Scala from Java, what they expected to use in Scala, what they actually did use in Scala, and the problems with Scala. Michael talked a lot about how he convinced his team to move to Scala as well. The experiences were positive but it did take a lot of convincing. The slides to his talk can be found here.
- Reactive Extensions (Rx): Curing Your Asynchronous Programming Blues - Sadly Erik Meijer was unable to present this. I forgot to write down the name of who did present it, Wes something, but he did a great job. Rx looks really cool. I don't know how it scales up in writing an application but Wes was able to throw together some interesting programs very quickly using Rx. Rx is a Reactive Programming library for .Net. In short, it treats events like a collection and you simply iterate over the collection to get events (you can even use LINQ). This makes writing even driven software easier to think about and easier to compose events together. All of his examples were in C# but, because Rx is on .Net, it can be used seamlessly with F# (is the impression that I got).
- Eden: An F#/WPF framework for building GUI tools - Eden is built by the Credit Suisse guys so they were unable to actually show Eden, however a subset of its functionality was built for the talk. This showed off more of how pretty GUIs can be created with F#. WPF has really great graphics and looked easy to produce. The portion of Eden shown was using a graph-based layout to calculate output on demand. It is difficult to explain succinctly but this talk showed off GUIs in F# as well as how easy it is to create asynchronous code. F#'s two strongest points seem to be OCaml's two weakest points.
- Functional Language Compiler Experiences at Intel - The speaker couldn't talk too much about what they were working on (apparently Intel is making a functional language designed to be used for their processors with many many cores) they they did have some interesting meta-things to say. The first was, even in the FP world, sometimes you just want impurity. The second was, if your FP language is going to allow you to write code imperatively, don't make the syntax terrible. In this case they were writing SML. Finally, it is harder to teach someone FP if they have programming experience than something completely fresh. In their case they were looking at 8 - 12 months before really getting a return from the people they were training.
- Riak Core: Building Distributed Applications Without Shared State - This talk was great. Rusty from Basho gave a great look at the important functionality in Riak. Riak is broken into three components: Riak Core - a core library for building robust distributed applications in Erlang, Riak KV - A key-value store using Riak Core, and Riak Search - a full text search engine using Riak Core. The message here, again, was the data center is the computer. I thought Riak's usage of virtual nodes was interesting too, and it seemed obvious in hindsight. Rather than break your distributed application up by physical nodes, create a ton of virtual nodes (more than you'll ever have of physical nodes) and then map those to physical nodes. Take sharding, for example, if you map to physical nodes, once you add a new physical node you'll have to repartition your shards all over again. But if you have a few hundred virtual nodes, adding a physical node just means you have to remap some data to it and point the new virtual nodes at it, but your upstream code doesn't need to change at all. Riak Core helps take care of the virtual node mapping for you as well as how to push data around when you add or take away physical nodes.
- Functional Programming at Freebase - I was excited for this talk but sadly let down. This involved rewriting Freebase's query language parser and executor from Python to OCaml. It looked more like mental masturbation to me though. Several times I found myself simply wonder why some choices were made. Many of the choices came off as wishing he were writing Haskell. In the end the speaker got a 10x speed up, which was pointed out to not be very good, and it looked like they had to go through a lot of headaches a long the way.
- ACL2: Eating One's Own Dogfood - I was unable to attend this talk.
I enjoyed CUFP quite a bit. It was great to meet the people I read papers from or see on videos about my favorite languages. In terms of being mainstream, Scala seemed to be making the fastest gains, most likely because it is so close to Java, it is an easy switch. In many ways I felt like we are all slowly catching up to Haskell. Many of the technical ideas presented here have already existed in Haskell for quite awhile and I could almost see the frustration on faces of the Haskell people wondering why the rest of us haven't figured out that we should be writing it. I'm hoping that next year the number of companies adopting functional languages continues to grow so we can see more examples of FP in industry at the next CUFP.