Haskell's Web Application Interface (WAI- pronounced "why") provides an abstraction between web applications and web servers. This allows many different web frameworks (e.g., Yesod, Spock, and Servant) to share servers like Warp and middlewares.

Haskell's web frameworks offer a wide variety of feature sets, type-level and metaprogramming, and intended use cases. And for most use cases, I would recommend using an existing web framework, which will help you avoid common pitfalls and more quickly address common use cases.

But not today! In this tutorial, we're going to step through building a functioning web server using just the bare-bones WAI interface and Warp as a server. Familiarity with the basics of Haskell will be a plus, but this will be a talk open to all FP and Haskell skill levels.

This full day workshop will focus on applying Haskell to normal, everyday programming. We'll be focusing on getting comfortable with common tasks, libraries, and paradigms, including:

• Understanding strictness, laziness, and evaluation
• Data structures
• Structuring applications
• Concurrency and mutability
• Library recommendations

By the end of the workshop, you should feel confident in working on production Haskell codebases. While we obviously cannot cover all topics in Haskell in one day, the goal is to empower attendees with sufficient knowledge to continue developing their Haskell skillset through writing real applications.

In this talk, we go back to first principles, defining and examining the definition for a cons list, then take a look at the ubiquitous right and left fold functions on a list.

The primary focus of this talk is to develop an intuition for how these functions work so that we can best decide when to apply them. Multiple programming languages will be used to help emphasise the independence of the gained intuition. This talk will generally be interactive with the audience as we solve problems and build confidence in our new knowledge.

Knowing how to apply the various list fold functions is a common question by the student of FP. This talk aims to provide a solid, reliable answer to this question. No prior understanding of list folds is necessary.

The term zipper is a colloquial used to describe n-hole (most often, 1-hole) contexts. That is, a data structure that has a _hole_ or _pointer_ focused on a specific element with the ability to efficiently traverse to its neighbouring elements, providing an elegant solution for the need to efficiently traverse and _modify_ immutable data structures.

In this talk, we will look at examples of zippers for canonical data structures such as lists and other products and sums. We will then define comonads and see the relationship between zippers and comonads.

Most of this talk will be spent on the practical application of zippers in everyday programming. We will solve some simple problems using zippers. We will then contrast why we might use a zipper, compared to a lens.

Finally, for a fun and interesting observation, we will look at the algebraic structure of products and sums, then compute the derivative of these structures. Turns out, a derivative of a data structure is its zipper ("McBride, Conor, et al (2005). ∂ for Data: Differentiating Data Structures").

Going from Java to Erlang is not hard if given proper support. This talk is about the roller coaster journey with Erlang to build a scalable, soft real-time transaction platform. If you are a Java developer struggling to understand and adapt to Erlang this talk is for you.

Language interoperability is the capability of two different programming languages to natively interact as part of the same system. Interoperability is advantageous because different programming languages are optimized for specific tasks, and allowing them to communicate can create better systems.

Apart from the Java language, the most common or well-known JVM languages are:

• Scala, a statically-typed object-oriented and functional programming language
• Clojure, a modern, dynamic, and functional dialect of the Lisp programming language
• Kotlin, a statically-typed language

In this session, we'll demonstrate how your program can interop with different JVM languages.

OCaml is a multi-paradigm programming language with a pragmatic mix of functional and imperative programming features. OCaml, which has been around since 1996, has grown to be a battle tested language, widely deployed and used in production systems. In this talk, we will look at the support for Generalized Algebraic Data Types (GADTs), a powerful generalization of the more mundane Algebraic Data Types (ADTs). We will start with an example of building an interpreter for a small language and add type safety through GADTs. We will then look at a few powerful type-safe design patterns that GADTs enable.

This session is an whirlwind tour of the FP land and is primarily meant for developers wanting to embark on their functional programming journey. We will use Java to understand most of the concepts, however, where it falls short to explain certain concepts, we will use Scala or Groovy or Clojure or even Haskell to demonstrate it. Starting with the basics - introducing the concepts with examples, we will evolve our understanding to take the mystery out of the monads (hopefully!)