e.near Tech Blog

Monads for the rest of us

There are a lot of articles around explaining functional programing and some of the theory and reasoning behind it. Most monad explanations are good if you understand the theory behind it. However, if you come from a practical standpoint, not so much. You will see the running joke that the first rule of Monads is that if once you understand the concept you lose the ability to explain it. This means you should not expect a lot from this post, because either I don’t understand the concept or the explanation is not very good. Either way, the aim here is to prescribe the monad as a good engineering tool.

Book Review: Functional and Reactive Domain Modelling

The Book Functional and Reactive Domain Modeling (Debasish Ghosh) is one of the most interesting books I have read lately, in the realm of Scala. This is not another beginner Scala book, neither a functional programming primer. It is a much needed tour on domain modeling with functional patterns and concepts, reactive systems and modern software development in Scala. If you want to know how in the world one can use Akka streams, free monads and actors interacting with each other, this book is a great starting point :).

Building Web applications with Scala.js and React - Part 1

As a Scala programmer developing Web applications, it is usually uncomfortable to move from a tidy, functional, and type-safe Scala back-end to an often subpar JavaScript front-end. Luckily for us, there are already some strong and mature alternatives to the Web’s (not so) lovely lingua franca.

Bits of Shapeless part 2: Generic Derivation

This is the second installment in a series of articles about Shapeless. The first post explained heterogeneous lists (HLists) and how to use them to do type-level recursion. Building on this ground, we will now talk about Generic derivation of case classes and sealed trait hierarchies. Along the way we shall cover other related subjects such as singleton-typed literals, products, coproducts (and labelled versions of those) and shapeless syntax goodies.

LX Scala

On April 9, Scala developers from Portugal, Spain and the UK gathered in Lisbon for LX Scala to discuss Scala’s present and future trends. These are my notes from the talks…

Hands on function composition with monad transformers

When using functional programming languages like Scala, developers spend a lot of their time composing functions and effects. One of the most common ways to express composability is to use monads. However, composing functions that return different monads can become quite messy and, without the right tools, quickly turn into a massive headache. That’s where Monad Transformers, which are the main focus of this post, come in handy!

Building a lexer and parser with Scala's Parser Combinators

As part of an ongoing project at e.near, one of our Scala teams was recently tasked with a requirement to build an interpreter for executing workflows which are modelled with a textual DSL. These workflows had to be validated for errors, compiled to a simpler bytecode-like representation and stored, in order to be interpreted with as little overhead as possible.