EuroClojure by Cognitect

Carin Meier

Cognitect

Keynote: Genetic Programming and Beyond with clojure.spec

Clojure.spec allows us to generate test data based on our specifications. But what about generating a clojure.spec program based off of data? With genetic programming, we’ll explore creating clojure.spec creatures that consume data for food. Then, we’ll breed, mutate, and evolve them until we have a perfect fitting spec for our data. Finally, we'll take a step back and think about how clojure.spec gives us the ability to have our programs describe themselves and what that means to AI and self-repairing code.

David Nolen

Cognitect

Now what?

Daniel Lebrero

IG

Automating resilience testing with Clojure and Docker

If you have read Michael Nygard's "Release it!" you know that a downstream service going down is just one of the many modes of failure that your new service will need to handle in production, and it is not even the worse one.

To make your system resilient, you also have to worry about networks going slow, disks getting full or third party services disappearing.

But how can we test those scenarios and make them part of our build pipeline?

During the presentation you will learn how to create a Clojure test suite that will use Docker to automate your resilience testing.

Dragan Djuric

University of Belgrade, Faculty of Organizational Sciences

Clojure is not afraid of the GPU

Today's hot topics, data science and machine learning, offer many algorithms that can turn lifeless data into useful information. Based on math-heavy theory, relying on number crunching, often billions and billions of raw operations must be performed quickly. Clojure can be teamed up with hardware accelerators or GPUs to offer both a cozy dynamic REPL environment and the speed and power of low-level hardware optimizations for numerical computations. In this talk, I present a few libraries tailored by the Clojure's measure, that can help achieve state-of-the-art performance: ClojureCL to direct the GPU, Neanderthal to help with vectorization and linear algebra, and Bayadera's incredibly fast MCMC engine. Clojure may not be able to compete with R and Python in the off-the-shelf machine learning, but for high-performance customized algorithms - it can be THE secret sauce.

Eric Weinstein

Hulu

Machine Learning with Clojure and Apache Spark

Machine learning has become an incredibly popular field of research in the last few years. While there's no shortage of libraries and tutorials in languages like Python and Java, there's relatively little in the world of Clojure. In this talk, we'll dive into machine learning with Clojure and Apache Spark! We'll start out comparing the Flambo and Sparkling libraries by building a binary classifier, then move on to exploring image recognition with a convolutional neural network developed with DeepLearning4J. You'll come away with a solid grasp of introductory theory as well as practical approaches to developing models and neural networks in Clojure.

Frederic Peschanski

UPMC

Live-coding Mathematics: your first Clojure proof

Have you heard about the lambda-calculus, dependent types, intuitionistic v.s. classical logic, or the Curry-Howard correspondence?

During this talk you will learn much about these, but not presented in the usual academic way... No! Clojure and Emacs/Cider will serve as learning vehicles, throughout a gently-paced live-coding Mathematics session !

For this we will use LaTTe, an open source proof assistant library for Clojure, probably one of the most addictive single-player puzzle game ever!

NB: no greek letters were harmed during the preparation of this talk.

Jean-Louis Giordano

Zimpler

A tale of ClojureScript in Production at a Payment Company

This is the story on how we moved to a Single Page Application using ClojureScript for our new payment checkout at Zimpler (a mobile payment company), the challenges we faced along the way, and how we setup the (optimal?) tooling for devs and designers alike. A tale of Figwheel, Amazon, re-frame, gulp, cache-busting, time-traveling debuggers, Honeybadgers, REPL-driven tests and broken iOS JIT compilers.

Daniel Janus

Rebased

A case study of natural language processing in Clojure

While Clojure is not a very popular choice for a language in which to implement natural language processing (NLP) tools, in this talk I'll show that it’s not only a feasible choice, but also a practical and pragmatic one.

I'll present two Clojure-based utilities, Smyrna and Skyscraper, that together allow to convert a series of texts in a morphologically rich language (Polish) to an easily and efficiently searchable corpus and to perform statistical analyses on this corpus. I'll also demonstrate a fairly large (>100M words) corpus built with these tools, the Polish Parliamentary Proceedings Processor (P4). I'll describe each of the tools in turn, how they fit together, and how Clojure allows for having the code concise and expressive while remaining performant.

I'll put the talk in context by comparing Skyscraper and Smyrna to other similar tools, and also look briefly at Smyrna’s ClojureScript and re-frame-based UI.

Malwine Gier

Microsoft

Arne Brasseur

Lambda Island

ClojureBridge Europe

ClojureBridge are fun, free and, welcoming workshops for learning programing and getting started with Clojure for groups of people that aren't well represented in our sector. Many workshops have been held around the world, including Europe. They inspire people to realize tech or art projects or switch careers. The Berlin chapter is especially active, with a workshop happening every six months. We love to share some of our experiences, both the challenges and the successes.

Michael Reitzenstein

Bookwell

Bare Metal Clojure with clojure.spec

Clojure provides powerful abstractions and dynamic typing, and its high performance is enabled only through the amazing optimizations provided by the powerful JITs in JVM, V8 et al.

Using Clojure's new spec and gen features, it's possible to generate specialized versions of Clojure code for constrained specifications, eliminating much of the boilerplate and branch heavy code, which can then be translated into efficient C.

This talk follows optimization of the humble (fn fib [n]) in its most naive form, using a series of generally applicable techniques to transform it from a O( 2ⁿ ) to a O( log n ) algorithm, generating efficient C that would be difficult to match by hand.

Michał Marczyk

Aviso

Priority Search Queues: 1.5-dimensional tree search

Priority Search Queues are an interesting abstract data type that simultaneously supports sorted map and priority queue operations in such a way that an entry's position in the map's sort order depends on its key, but its priority, as used by the priority queue operations, depends on its value. Additionally, these aspects of PSQs mesh together, so that one can iterate over precisely those entries whose keys fall in between a certain pair of keys and whose values are less than some particular value, in effect performing a 1.5-dimensional search of the PSQ.

PSQs have been given a particularly elegant presentation and implementation - in Haskell - by Ralf Hinze in his 2001 paper "A Simple Implementation Technique for Priority Search Queues". This talk aims to examine the main ideas behind Hinze's concrete realization of PSQs, to briefly compare it to Edward M. McCreight's original PSQ implementation from the "Priority Search Trees" paper of 1985, and finally to place PSQs in a Clojure context.

Mike Pearson

University of Cambridge, DPMMS

Communicating Risk Reactively

An experience report on how Clojurescript, React and Rum helped develop a project that started as a medical animation of risk adjusted mortality data, and rapidly morphed into a single page web site tackling some controversial and tricky issues. It's a story of researchers learning the needs of users and changing how they communicate, and of one programmer trying to keep up.

As an appendix, I shall add some thoughts and demonstrations of custom plots written in clojurescript for researchers who use R.

Peter Brachwitz

Cisco

Clojure is a Foreign Country: Combining Datomic with Scala

What happens if you use Datomic from a non-Clojure application? How well do Datomic's concepts and its advertised strengths hold up when used from a Scala application? Expect an experience report from the battlefield of the day-to-day. I will talk about mistakes we made, benefits we reaped and explore what foreignness means when talking about technological solutions.

Simon Belak

GoOpti

Living with spec

We instrumented 15k LOC codebase with spec so you don't have to (but probably should). Validation; testing; destructuring; composable "data macros" via conformers; we've tried spec in all its multifaceted glory. This talk is a distillation of lessons learned interspersed with musing on how spec alters development flow and one's thinking.

Srihari Sriraman

nilenso

Making machines that make music

Music synthesis is commonplace in Clojureland. However, modeling Carnatic (south indian classical) music, then generating and machine-learning it has been attempted by only a few, and is a very interesting problem to solve.

This talk is the story of my journey in bridging the gap between machine and human music. We will teach machines the fundamental concepts, create models that identify Carnatic music, and then build models that allow the machines to learn music themselves, and in the process, teach us.

The talk will (obviously) include demos of comparisons of machine and human (my) music, code snippets of implementation in Clojure/Overtone, and pretty melographs.

Thomas Neuhalfen

freelancer

GeoRepl - Interactive Geometry with Clojure

GeoRepl is an OpenSource software written entirely in Clojure using Quil as basic GUI framework. GeoRepl is an interactive geometry application which lets you examine and manipulate the symbolic representations of the geometric constructions in a Clojure Repl as well. GeoRepl follows a concept of user interaction allowing the user to draw intuitively and "menue-less" using freehand symbol recognition, snapping, dragging and dashing.