Scala

by: Bogdan Kolbik and Fabian Braun We at MOIA use both Scala and Rust together in one application, and it’s great. Here’s why we do it and how we do it. Why It all started with an application for optimizing vehicle routes. Optimization problems are quite tricky: there can be many…

One misconception when first learning about fold is that it takes a list of elements of a certain type (List[T]) and “reduces” it to a single item of type T. This misconception is aided by one of the most common fold examples: summing a list. Scala Example: List(1, 2, 3…

In this seventh post about cats effects we will continue writing down the most interesting things from the book “Essential Effects” by Aleksandar Prokopec. We are using the Cats Effects 3 library but the book is based on both version 2.2.0 and 3 ⚠️ Continuation Code that will be executed “next”…

In a recent post, I talked about how corecursion is a great solution for removing redundant calculations. However if we’re sticking to a recursive approach, one way we can reduce redundancies is to use memoization. …

Fold is a functional programming pattern that operates over some sequence with a binary operation and a starting value. There are two variants: FoldLeft: Performs the binary operation from the left of the sequence to the right. List(1, 2, 3, 4).foldLeft(0)(_ …

Recursion takes a large problem and breaks it down until it reaches some base cases. One popular example, is the factorial function. def fact(x: Int): Int = if x == 0 then 1 else if x == 1 then 1 else x * fact(x - 1) Though we can similarly…

In functional programming, we often look at a list in terms of its head (first-element) and tail (rest-of-list). This allows us to define operations on a list recursively. For example, how do we sum a list of integers such as [1, 2, 3, 4]? def sum(l : List[Int]): Int =…

Self-types are a way to declare that a trait must be mixed into another trait, even though it doesn’t directly extend it. The self-type definition can be utilized to access the superclass. Further information on this topic can be found here. However, it is assumed that the reader of this…