2020 Retrospective (and What's Coming in 2021)
7 min read • • Retrospective
In this article, I'll recap 2020's highlights, share key insights and achievements, and unveil exciting plans for the future of Rock the JVM
Founder | Rock The JVM
Articles written by 'Daniel Ciocîrlan'
Daniel Ciocîrlan
Software engineer and best-selling instructor. I'm an avid fan of Scala, Kotlin, functional programming, big data and streaming. As of May 2023, I've taught more than 80000 people all over the world.
2021 Retrospective (Blog, Socials, and More!)
5 min read • • Retrospective
Wrap up 2021 with us as we review the year's highlights and achievements at Rock the JVM
Founder | Rock The JVM
3 Fun Call-by-Name Tricks in Scala
5 min read • • Guide
Maximize call-by-name semantics in Scala: control when your results are evaluated
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4 Handy Ways to Read Files in Scala
3 min read • • Explanation
Master file reading in Scala with ease: compare it to other languages and discover how our simple API approach is almost as straightforward as Python's read()
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5 Fun Code Expressiveness Tricks in Scala
4 min read • • Guide
Scala is an incredibly expressive language: discover hidden features that even experienced developers might miss!
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8 Pattern Matching Tricks in Scala
7 min read • • Guide
Pattern matching is one of the most powerful Scala features: learn to use it to the max and write your best Scala code
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A Backtracking Sudoku Solver in Scala
13 min read • • Explanation
Master solving Sudoku and other constraint-satisfaction problems with recursive backtracking in Scala
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A Fresh Perspective on Monads: Generalizing Chained Computations
6 min read • • Guide
Explore a fresh perspective on monads: Discover new angles on this familiar concept with Rock the JVM
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A Comprehensive Guide to Choosing the Best Scala Course
12 min read • • Guide
Discover the best Scala course for your learning journey: explore recommended courses and libraries such as Cats Effect, ZIO, and Apache Spark
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A Monad Is a Monoid in the Category of Endofunctors: Scala Explanation
12 min read • • Explanation
What's the problem?
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A Scala Project with Akka, Cats, and Cassandra
30 min read • • Guide
Akka, Cats, and Cassandra in a larger Scala project integrating multiple pieces of the Scala ecosystem
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Abstract Classes vs Traits in Scala: Practical Differences
3 min read • • Explanation
Abstract classes and traits share a lot of overlap in Scala: discover how they actually differ
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Akka HTTP Loves JSON: 3 Libraries You Can Integrate into Akka HTTP
8 min read • • Guide
Akka HTTP needs JSON like humans need water: discover how to integrate Spray-Json, circe, and Jackson into Akka HTTP
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Akka HTTP to Heroku in 10 Minutes
5 min read • • Guide
Easily deploy your first Akka HTTP service to Heroku in minutes
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Akka Streams Backpressure Explained
10 min read • • Guide
Discover how Akka Streams implements backpressure, a key component of the Reactive Streams specification, in this detailed demonstration
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Akka Typed: Actor Discovery with Akka Receptionist
11 min read • • Guide
A common pattern in Akka Typed: discovering how to find actors not explicitly passed around
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Akka Typed Actors: Stateful and Stateless
7 min read • • Guide
Akka Typed has transformed actor creation: in this article, we explore various methods for managing state within Akka actors
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Akka Typed: Adapting Messages Explained
8 min read • • Guide
Learn how to organize code, messages, domains, and logic in an Akka application with Scala
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Akka Typed: How the Pipe Pattern Prevents Anti-Patterns
6 min read • • Explanation
Discover how Akka Typed revolutionizes actor protocol definitions and dramatically enhances actor mechanics
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ALL the Joins in Spark DataFrames
7 min read • • Explanation
Spark supports more types of table joins than you might expect: discover the different join options in this article
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An Introduction to Monads in Scala
9 min read • • Explanation
A Scala tutorial on Monads that starts with practical needs and builds up from scratch: derive the monad patterns (laws) with no assumptions
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Broadcast Joins in Apache Spark: An Optimization Technique
7 min read • • Explanation
Broadcast joins in Apache Spark are a highly effective technique for boosting performance and avoiding memory issues, offering great value for optimization
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Building a Full-Stack Scala 3 Application with the Typelevel Stack
26 min read • • Guide
Unlock the secrets to crafting a full-stack Scala 3 application from scratch: dive into Cats Effect, doobie, http4s, and Tyrian and build robust, modern software with ease
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Cats Effect 3: Introduction to Fibers
6 min read • • Explanation
An Introduction to Asynchronous Computations with Fibers in Cats Effect 3, Tailored for Scala 3
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Cats Effect 3: Racing IOs Explained
5 min read • • Guide
Following the introduction to concurrency in Cats Effect: explore advanced techniques for managing racing IOs and fibers
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Cats: Essential Type Class Hierarchy Explained
9 min read • • Explanation
Cats is a complex library for Scala: This article deconstructs the major type classes and explains their connections
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Comparing Akka Streams, Kafka Streams and Spark Streaming
14 min read • • Guide
Explore how Akka Streams, Kafka Streams, and Spark Streaming stack up and find out which one is best for your use case
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Controllable Futures in Scala Explained
3 min read • • Explanation
Learn how to handle deterministic Futures in Scala using Promises in this article
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Create Your Own Custom String Interpolator
4 min read • • Guide
Discover how to create your own custom string interpolator that feels like a native feature of Scala
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Custom Pattern Matching in Scala
6 min read • • Guide
Pattern matching is one of Scala's most powerful features: discover how to customize it and create your own patterns in this article
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Demystifying Variance Positions in Scala
11 min read • • Explanation
Explore the infamous 'covariant type occurs in contravariant position' problem in Scala: discover effective solutions and best practices
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Deploy a Scala Application to AWS Lambda
4 min read • • Guide
Deploying Scala Code to AWS Lambda Is a Breeze: Discover Our Step-by-Step Tutorial to Guide You Through the Process
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Enums in Scala 3: Quickly Explained
3 min read • • Explanation
Scala 3 Introduces Enums: A Major Update with Significant Implications
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Eta-Expansion and Partially Applied Functions in Scala
5 min read • • Explanation
Explore the intriguing world of eta-expansion: Discover how methods and functions interact in Scala, revealing insights that can elevate your coding game
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Evaluation Modes in Scala Explained
4 min read • • Explanation
Explore core Scala constructs from a fresh perspective and uncover new insights into their use and application
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Exploiting Implicit Ambiguity in Scala
6 min read • • Explanation
Discover how to use Scala's implicit resolution to enforce type relationships at compile time
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Finagle: Twitter's RPC Library for Scala
10 min read • • Explanation
Discover Finagle: a powerful yet deceptively simple library for building distributed systems, offering built-in HTTP support, seamless load balancing, and more
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Free Monads in Scala Explained
16 min read • • Explanation
A tutorial on Free Monads in Scala: Explore how they work and discover their benefits
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Functional Collections in Scala
7 min read • • Explanation
Discover a powerful Scala feature that many developers overlook: a concise guide to functional collections that could revolutionize your Scala programming
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Getting Started with Scala Generics
8 min read • • Explanation
Scala generics are a breeze for Java developers, but what about those coming from Python or JavaScript?
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Getting Started with Scala Options
9 min read • • Explanation
Scala Options are among the first concepts we encounter: Discover what they do, why they're useful, and their importance in programming
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Higher-Order Functions for Object-Oriented Programmers
5 min read • • Explanation
For OO programmers looking to dive into functional programming in Scala: a gentle introduction to functions working with other functions
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How Akka Typed Incentivizes Writing Good Code
5 min read • • Explanation
Explore how Akka Typed integrates good practices directly into the API
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How Does the '20 Seconds' Idiom Work in Scala?
4 min read • • Explanation
Various idioms like '20.seconds' seem built into Scala: discover how these idioms work
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Idiomatic Error Handling in Scala
9 min read • • Guide
Error handling can be one of the most frustrating aspects of programming: let's explore how Scala offers better and worse ways to manage it
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Immutable Linked Lists in Scala With Call-By-Name and Lazy Values
10 min read • • Guide
Discover how to harness lazy values and call-by-name techniques to craft a fully immutable doubly-linked list in Scala
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Lenses, Prisms, and Optics in Scala
6 min read • • Explanation
Inspect, extract, and modify deeply nested data structures in Scala with ease: discover a powerful method to handle complex data effortlessly
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Make a Snake Game with Scala in 10 Minutes
12 min read • • Guide
The ultimate 10-minute guide to building a Snake game in Scala: learn fast and code smarter
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Much Ado About Nothing in Scala
4 min read • • Explanation
Explore the `Nothing` type in Scala: A short trip to nothingness and its unexpected usefulness
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Mutability in Scala Quickly Explained
5 min read • • Explanation
Although frowned upon by FP purists, creating and managing mutable data structures is important in any language: Explore Scala's first-class mutability features
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N-Queens in Scala: How to Approach Algorithm Questions
1 min read • • Explanation
Learn how to tackle a Google-style algorithm interview question in Scala using pure functional programming
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Objects and Companions in Scala
5 min read • • Explanation
This article is for beginner Scala programmers: an introduction to singleton objects and companion objects, exploring their uses, benefits, and best practices
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Organizing Services with ZIO and ZLayers
12 min read • • Guide
ZIO layers (ZLayers) help structure complex services into independent, composable, and easy-to-understand modules: discover how they can simplify your architecture
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Refined Types in Scala Quickly Explained
5 min read • • Explanation
Explore how to impose constraints on values at compile time using the Refined library
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Repartition vs Coalesce in Apache Spark
5 min read • • Explanation
Clarifying the differences between two essential repartitioning operations in Apache Spark
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Scala 3: Anti-Givens Quickly Explained
4 min read • • Guide
Discover a Scala 3 trick few developers know: leveraging the absence of a given instance to enforce type constraints
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Scala 3: Extension Methods Quickly Explained
4 min read • • Explanation
Deconstructing extension methods: one of the most exciting features of the upcoming Scala 3
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Scala 3: General Type Projections
7 min read • • Explanation
Scala's general type projections are considered unsound and were removed in Scala 3: discover what this means and how it affects your code
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Scala 3: Given and Using Clauses
7 min read • • Explanation
Explore Scala 3's given/using clauses: a crucial feature for modern Scala programming, and learn how to leverage them effectively
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Scala 3: Givens and Implicits Quickly Explained
5 min read • • Explanation
This quick article demonstrates how Scala 3's given instances integrate seamlessly with Scala 2's implicits
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Scala 3: Givens vs Implicits Quickly Explained
7 min read • • Explanation
Building on the previous article's insights into givens, let's explore how they stack up against the traditional Scala implicits
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Scala 3: Indentation Quickly Explained
6 min read • • Explanation
Some people love it, some hate it: Scala 3's indented syntax might surprise you with its potential to enhance your code structure
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Scala 3: Mastering Path-Dependent Types and Type Projections
5 min read • • Explanation
Unlock advanced programming techniques with Scala 3: explore dependent types, methods, and functions in this concise tutorial
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Scala 3: Match Types Quickly Explained
7 min read • • Explanation
Scala 3 comes with lots of new features: in this episode, we dive into match types, a powerful tool for pattern matching on types and more accurate type checking
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Scala 3: New Types Quickly Explained
7 min read • • Explanation
Explore the Game-Changing New Types in Scala 3: What We're Eagerly Anticipating
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Scala 3: Opaque Types Quickly Explained
4 min read • • Explanation
Explore opaque type aliases in Scala 3 and learn how to define new types with zero overhead
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Scala 3: Traits Quickly Explained
4 min read • • Explanation
This article delves into Scala 3's advanced trait functionalities, building on our previous explorations of the language's new features
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Scala 3: Type Lambdas Quickly Explained
4 min read • • Explanation
Exploring type lambdas in Scala 3: a quick yet powerful structure that will elevate your high-level thinking
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Scala Testing with ScalaTest: A Beginner's Guide to Testing Styles
7 min read • • Guide
In this article, we explore the main testing styles in Scala and ScalaTest: understanding what terms like 'FunSuite' and 'FlatSpec' really mean
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Self-Types in Scala: A Quick Overview
3 min read • • Explanation
Self-types are a powerful way to enforce type constraints in Scala: learn to use them effectively in just a few minutes
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Semigroups and Monoids in Scala
8 min read • • Explanation
This article provides a gentle introduction to Monoids and Semigroups, exploring functional abstractions and the workings of the Cats library
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Sending HTTP Requests with Scala and Akka in 5 Minutes
4 min read • • Guide
Learn to use Akka HTTP with Scala and send HTTP requests in just a few minutes with the Akka HTTP server DSL
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Sort Lists in Scala with Tail Recursion
6 min read • • Guide
Master List Sorting with Tail Recursion in Scala: Enhance Your Functional Programming Skills and Boost Your Interview Readiness!
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Stateful Streams with Apache Pulsar and Apache Flink
22 min read • • Guide
Discover how to integrate Apache Pulsar with Apache Flink: perform advanced data enrichment using state from multiple topics
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Streaming Analytics with Apache Pulsar and Spark Structured Streaming
13 min read • • Explanation
Explore Apache Pulsar's role in event streaming and computing: discover practical use cases and learn when to integrate advanced computing engines for sophisticated stream processing
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Sync, Async, and (Non-)Blocking in Scala and Akka
5 min read • • Explanation
We explore the trade-offs between three parallel coding styles in Scala and Akka: focusing on thread usage and other effects
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Tagless Final in Scala Quickly Explained
12 min read • • Explanation
Demystify the tagless final pattern in Scala: it's not about type classes
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The Big Kotlin Tutorial: Comprehensive Guide
38 min read • • Guide
Learn Kotlin with the ultimate, comprehensive, and hands-on guide
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The Brilliance of Materialized Values in Akka Streams
7 min read • • Explanation
Demystify one of the hardest concepts in Akka Streams: materialized values made simple
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The Differences Between Null, Nothing, Nil, None, and Unit in Scala
4 min read • • Explanation
Discover the different flavors of 'nothing-ness' in Scala and how they impact your code
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Things That Don't Make Sense: Scala Loops
5 min read • • Opinion
Daniel dives into another rant about learning (and teaching) Scala with loops: Are they truly useful?
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Things That Don't Make Sense: Scala Variables
3 min read • • Opinion
Daniel shares a candid rant on the challenges of learning and teaching Scala with variables
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Top 10 Skills and Mental Models for Becoming a Scala Developer
10 min read • • Guide
Mastering Scala can be simple: discover 10 key mental skills to excel as a Scala developer
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Type-Level Programming in Scala 3: Part 1 - Comparing Types
9 min read • • Guide
Harness the power of givens to infer type relationships in Scala 3: at compile time
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Type-Level Programming in Scala 3: Part 2 - A Quicksort on Types
16 min read • • Guide
Level 90 of type-level programming: implementing a real sorting algorithm on lists as types
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Type-Level Programming in Scala: Part 1 - Numbers and Comparisons
7 min read • • Guide
Harness the full power of Scala's type system: let the compiler infer complex type relationships for you at compile time
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Type-Level Programming in Scala: Part 2 - Adding Numbers as Types
11 min read • • Guide
We continue exploring type-level power in Scala: adding numbers as types at compile time
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Type-Level Programming in Scala: Part 3 - Sorting Lists
17 min read • • Guide
The final chapter in our type-level trilogy: mastering list sorting at compile time
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Types, Kinds, and Type Constructors in Scala
6 min read • • Explanation
Discover Scala's powerful type system: explore type organization, type constructors, and their significance
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Underscores are Overloaded in Scala!
4 min read • • Explanation
Scala syntax can be confusing: discover almost all uses of underscores and why understanding their inconsistent philosophy is worthwhile
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Understanding Spark DAGs (Directed Acyclic Graphs)
6 min read • • Guide
Discover the essential skill for optimizing Spark performance: mastering the Spark UI and understanding the job execution graph
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Understanding Spark Query Plans
6 min read • • Guide
In this article, you'll learn one of the most important Spark skills: reading how your job will run, which is foundational for any further Spark optimization
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Use Akka Streams' Graph DSL: Quickly Explained
7 min read • • Guide
Explore Akka Streams' powerful Graph DSL and learn how to get started quickly with our easy guide
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What Is Referential Transparency and Why Should You Care?
7 min read • • Explanation
Discover how referential transparency boosts your productivity as a functional programmer in Scala and why it's crucial
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What the Functor? Exploring Functors in Depth
5 min read • • Explanation
Explore one of the most essential concepts in pure functional programming: the Functor, a crucial but abstract idea that will challenge your understanding
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Why are Scala Type Classes Useful?
4 min read • • Explanation
FP fans discuss the challenge of type classes in pure functional programming with Scala: why are they difficult, and why do we really need them?
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Why Is Contravariance So Hard in Scala?
4 min read • • Explanation
Unravel the complexities of Scala's powerful type system with our deep dive into contravariance: we simplify and demystify its challenging aspects
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