Clojure/West 2015

Random number generation is unsettled territory in the Clojure ecosystem. The language's built-in mutable random number generator is not helpful for more purely functional approaches. An immutable, splittable RNG has an ideal interface, but is challenging to implement robustly. This talk will motivate the topic by showing how switching to splittable RNGs makes the implementation of test.check (the property-based testing library) more solid, and describe an implementation of a splittable RNG in Clojure based on recent research.

• Sat, Jan 1, 09:00 - 09:40

Zelkova is a library for Functional Reactive Programming (FRP) that lets you compose your Clojure or ClojureScript application as a graph of "signals" defined using pure functions. It is heavily inspired by Elm, a language which embraces an innovative flavour of first-order FRP as its central paradigm. This talk will show Zelkova in action, demonstrating how it can be used together with GUI libraries like Om and Reagent to solve practical problems while making state management unexpectedly fun.

• Sat, Jan 1, 09:00 - 09:40

Lisps are a great starting point for teaching computer science since they allow introduction of essential concepts, such as functional abstraction, recursion, and higher-order functions. Clojure provides additional benefits for novice programmers due to its rich set of data structures and predefined functions, easy access to concurrent processing, and an active open source and industry community. However, in order to introduce Clojure in an introductory programming class for students with no programming experience, one has to address several challenges, such as non-beginner-friendly error messages and a lack of a beginner-friendly IDE. In this talk I will discuss progress that my students and I have made towards filling in the missing pieces for incorporating Clojure into an introductory class.

• Sat, Jan 1, 09:50 - 10:30

Sonian's been using Clojure in production, at large scale, for 6 years. In that time, we've developed a common foundation for back-end Clojure services, embodied in our SAFE codebase. For this talk, I'll walk through the major features of that foundation, explaining the reasons each was chosen and how they work together to make building new Clojure services easier.

• Sat, Jan 1, 09:50 - 10:30

Debugging Clojure code has traditionally been something of a black art. Cursive provides a complete JVM debugger based on the one provided in IntelliJ, including breakpoints, stepping and expression evaluation. In this talk, we'll see some of the features that Cursive provides to make debugging easy and discuss some tricks and tips for debugging Clojure code. We'll also discuss the JDI that the debugger is based on, and how some of its limitations affect debugging functional languages.

• Sat, Jan 1, 10:40 - 11:20

Clojurescript community has been slow to embrace Garden, a simple library for rendering CSS in Clojure/ClojureScript. Conceptually similar to Hiccup, Garden allows you to design pages and layouts like a functional programmer: plain-old data structures, functions, and abstractions. In this talk I will focus on responsive grid techniques popularized by Bootstrap, Susy, Flexbox, followed by a live-coding session. We will explore how to implement fluid, responsive, nested, and even DIY grids with Garden, and render CSS3 on the server or client. We will end with a demo of a page designed in Garden, rendered with Om, to showcase the benefits of using Clojurescript all the way.

• Sat, Jan 1, 10:40 - 11:20

Suppose you'd like to teach Clojure in your local community and are the first person to do--where would you start? You'd need a nice and clear curriculum with focused exercises and simple-but-engaging apps; however, soon, you'd find that writing such curriculum on your own is a difficult task. That's why ClojureBridge curriculum team has been collaborating on its own new Clojure curriculum, so that people from all backgrounds can enjoy coding in Clojure. It is as if the team is walking, sometimes staggering, on a long and winding road leads to a better curriculum for beginners. In this presentation, you'll learn what the curriculum team has accomplished so far, what work is on the horizon, and how you can offer your input, ideas, and help now.

• Sat, Jan 1, 13:00 - 13:40

While the software industry contemplates how to increase diversity in its ranks, what if Clojure could be the very tool to spread Clojure (and programming in general) to the world of non-English speakers? By seriously considering the macro perspective, we can see how simple ideas can lead to opportunities for lasting change. How far could we extend these efforts in Clojure-esque simplicity? Find out what makes Clojure uniquely suited to supporting other human languages.

• Sat, Jan 1, 13:00 - 13:40

Have you ever wanted to try your hand at designing and building a language, only to be driven away by ancient and obtuse tools? Clojure makes an excellent sandbox for quickly designing and prototyping new language ideas. This talk lays out a roadmap for the aspiring language inventor, from design to parsing to building a runtime.

• Sat, Jan 1, 13:50 - 14:30

Yieldbot's data platform is built on top of clojure. I will cover some of our experience using clojure for data (sciencing and platform). I will cover our two major open source projects, marceline, a clojure dsl for apache storm/trident, and flambo, a clojure dsl for apache spark.

• Sat, Jan 1, 13:50 - 14:30

To reach a diagnosis, a medical professional must now consider not only a sea of symptoms, but also an increasing number of factors: genotypes, functional genetics, proteomics, etc.. Caretakers, insurers, governments, medical researchers and most of all patients are looking technology satisfy their disparate goals. I will describe how our team is using Clojure, Datomic and React to provide a more humane medium for real-time collaboration. The primary focus of is to propose systems that scale well with high intrinsic sociological complexity. I will give a development log of how we are attempting to enable all parties in the healthcare ecosystem to create interactions, giving agency to the machine to participate on their behalf in the moment medical encounter.

• Sat, Jan 1, 14:40 - 15:20

Good Clojure practice emphasizes programming with immutable data. Another practice which can greatly simplify your code is declarative programming via pattern matching. Powerful pattern matching libraries such as core.match and defun give Clojure pattern matching abilities that rival Prolog and Erlang. This session is an experience report and best practices from extensive use of pattern matching libraries in recent open source Clojure projects.

• Sat, Jan 1, 14:40 - 15:20

Arcadia is the integration of Clojure into the Unity 3D game engine and development environment. Unity exports to nearly all major gaming platforms, while Clojure's functional data and capacity for live programming and optimizing macros provide unique benefits to game developers. We will discuss progress since our last release, the internals of the Arcadia compiler, and the ramifications of industrial game development in Clojure, with live usage demos.

• Sat, Jan 1, 15:40 - 16:20

Arcadia is the integration of Clojure into the Unity 3D game engine and development environment. Unity exports to nearly all major gaming platforms, while Clojure's functional data and capacity for live programming and optimizing macros provide unique benefits to game developers. We will discuss progress since our last release, the internals of the Arcadia compiler, and the ramifications of industrial game development in Clojure, with live usage demos.

• Sat, Jan 1, 15:40 - 16:20

Programmers hate Excel, but we often have to deliver results as spreadsheets. This is what we miss: used correctly Excel is a tool of tremendous expository power that can enable richer communication. I'm going to show you what makes a spreadsheet beautiful and how you can create beautiful spreadsheets from pure Clojure data structures using the Excel templates library. Along the way, we'll discuss how to use spreadsheets to enhance understanding of quantitative data throughout our organizations.

• Sat, Jan 1, 15:40 - 16:20

Because they are computed, generative art systems necessarily explore a state space, but many of their state spaces exhibit wild variations in visual interestingness across their domain. This makes them unsatisfying to use in live performance, since they'll lapse into the boring parts and resetting the state to restore it is visually unpleasant. In this talk I'll give an introduction to generative art with a focus on iterated fractal systems in particular, which have some absolutely fascinating portions of state space alongside very boring ones. I'll present Many Worlds, a system that visualizes state space traversals ahead of time remotely to allow the user to find a compelling state path in an interactive, iterative way.

• Sat, Jan 1, 16:30 - 17:10

Gather round and hear the harrowing tale of how Chris saved his Chickens from the evil raccoons using Clojure on a BeagleBone Black to automatically shut and lock the coop door at night and open it in the morning, using ambient light sensors to ascertain the time of day. Learn what it took to get Clojure running on the BBB, what some of the challenges were, and how Clojure handled for device programming. Get a sneak peak of libraries being extracted from this project, which you'll be able to use for general purpose device programming. Bask in glorious victory with Clojure and the dancing chickens.

• Sat, Jan 1, 08:45 - 09:05

Mobile development is the next great frontier for the Clojure ecosystem. Traditionally, mobile Clojure apps have been trapped in a WebView, resulting in limited capabilities and a less-than-steallar user experience. This is no longer the case. Come hear about production examples leveraging the existing Clojure ecosystem to build real, native mobile applications. No strings, caveats, or restrictions.

• Sat, Jan 1, 09:10 - 09:50

Queues, it seems, are back in fashion. This is exciting, as queues let us explore problem spaces that were unreachable by pure, immutable primitives. But queues, and the execution models that drive them, are very different than what we're used to. Naive use of libraries like core.async will create brittle, unpredictable systems that fall over when we least expect. This talk will cover the basics of queueing theory, and its practical application in Clojure systems large and small.

• Sat, Jan 1, 09:10 - 09:50

Figwheel is a tool that helps ClojureScript programmers. It facilitates a live interactive programming workflow and much more. In this talk, I will go over the main ideas behind Figwheel and demonstrate how it works. I will explore several tricks to help people get the most out of using it. The goal of this talk is for attendees to walk away with a solid understanding of Figwheel and its use.

• Sat, Jan 1, 10:00 - 10:40

There are many resources to help you build Clojure applications. Most however use trivial examples that rarely span more than one project. What if you need to build a big clojure application comprising many projects? Over the three years that we've been using Clojure at WalmartLabs, we've had to figure this stuff out. In this session, I'll discuss some of the challenges we've faced scaling our team and code base as well as our experience using Clojure in the enterprise.

• Sat, Jan 1, 10:00 - 10:40

I will describe my current research on building computer systems that can recognize visual situations. While much effort in computer vision has focused on identifying isolated objects in images, what people actually do is recognize coherent situations—collections of objects and their interrelations that, taken together, correspond to a known concept, such as “a child’s birthday party”, or “a man walking a dog on the beach”, or “two people about to fight”, or “a blind person crossing the street”. Enabling computers to flexibly recognize visual situations would create a flood of important applications in fields as diverse as medical diagnosis, interpretation of scientific imagery, enhanced human-computer interaction, and personal information organization. Situation recognition by humans may appear on the surface to be effortless, but it relies on a complex dynamic interplay among human abilities to perceive objects, systems of relationships among objects, and analogies with stored knowledge and memories. No computer vision system yet comes close to capturing these human abilities. In this talk I will describe research—currently in early stages—on bridging the gap between low-level perception and higher-level image understanding by integrating a cognitive model of concepts and analogy-making with a brain-inspired “deep network” for lower-level vision.

• Sat, Jan 1, 10:50 - 11:30