Eta compiles Haskell code to Java/JVM bytecode. It supplies a Foreign Function Interface for interoperating with Java code. Many existing Haskell libraries (e.g. lens, Servant, QuickCheck) are ported to Eta so it's possible to use them for many traditionally Java environments, including Amazon Lambda functions, Kinesis consumers and Spark jobs.

The Nix expression language allows writing functions to specify builds. The Nix build tool takes these expressions and instantiates them into static build instructions. These instructions can then be realised and turned into outputs. At each step Nix' tooling provides a layer of purity.

Using Eta and Nix together, we can use Haskell functions for applications and Nix functions for builds, then deploy them to Java environments!

Following Tony and Alois' Introduction to Haskell syntax and tools, we will work through the first few modules of Data61's Functional Programming Course. These modules cover writing functions for the optional and list data types.

We will complete enough exercises to cover basic data types, functions and polymorphism. We'll practice the techniques of equational reasoning, parametricity and type/hole driven development. After completing these modules, you should be able to use the techniques to attempt most other exercises in the repository.

This workshop has the same requirements as Tony's introduction, along with a download of a recent version of the fp-course repository (https://github.com/data61/fp-course).

My team works on Atlassian Marketplace, a project which started 10 years ago and uses Scala, Haskell and Nix. The Marketplace code uses concepts such as applicative functors, monad transformers and lenses. People joining the team mostly learned concepts as they needed to, through experimentation and asking questions.

Last year we started hosting functional programming classes for more fundamental and broad understanding. We've been using the Data61 (formerly NICTA) Functional Programming Course with a lot of success. This talk will describe how we teach FP, what we've learned about teaching FP and the challenges we face.

PureScript is a small, typed, functional programming language which compiles to JavaScript. Some of the goals are to require no runtime by compiling to minimal JavaScript and to provide a simple Foreign Function Interface to interact with existing JavaScript. PureScript has seen some commercial adoption and has many libraries available for writing functional web front-ends.

This workshop will cover writing an interactive web application using PureScript. 

We are constantly presented with trade-offs when writing software. What are the trade-offs when applying functional programming? What costs arise? When is it not worth doing? When should pragmatism kick in and when should we start using side-effects?

This talk will give you some tools to be able to answer the above questions for both functional programming and types. The tools have been refined over many professional years of both doing and not doing purely functional programming.