Scala resources

Here is the list of my favorite articles collected during my 10 years of language practice.

Best practices

• Why are Default Parameter Values Considered Bad in Scala?
• try-with-resources
• scala-best-practices
• ADT
• referential transparency

Type System

Awesome overview

• Kinds of types in Scala, A master piece, highly recommended read
• Scala’s Types of Types
• Types in Scala

Specific topics

• Phantom Types in Scala phantom types never get instantiated. They are used to encode type constraints.
• Type members are [almost] type parameters type members VS type parameters.
• When are two methods alike?
• A short introduction to the Aux pattern a trick to overcome a limitation with path dependent type.
• Generalized Algebraic Data Types in Scala
• Returning the “Current” Type in Scala An F-bounded type is parameterized over its own subtypes. trait Pet[A <: Pet[A]]. And also subtyping VS ad-hoc polymorphism.
• Fake Theorems for Free why you should not use Object#equals and Object#hashCode
• Compiler plugin for making type lambdas (type projections) easier to write
• Generalized type constraints in Scala (without a PhD), About <:< and =:= syntax
• Avoiding Unnecessary Object Instantiation with Specialized Generics, @specialized
• Type classes in Scala
• Generics of a Higher Kind
• Overcoming type erasure in Scala

Category theory

• Functors, Applicatives, And Monads In Pictures
• The Essence of the Iterator Pattern
• Free Monoids and Free Monads
• Monoid Morphisms, Products, and Coproducts
• A tale on Semirings
• How can we map a Set?, on coyoneda

Advanced - Free monad VS tagless final

• Stackless Scala With Free Monads
• On Free Monads
• Introduction to Tagless final
• Exploring Tagless Final pattern for extensive and readable Scala code

Concurrency

• An IO monad for cats
• Shared State in Functional Programming
• Why should you care about RT
• Thread Pools
• Talk - Intro to Cats-Effect (Gavin Bisesi)
• Talk - The Making of an IO - Daniel Spiewak

Various

• Implicit Design Patterns in Scala
• Scrap Your Cake Pattern Boilerplate: Dependency Injection
• A brief tour of Scala: two classic problems, Fibonacci …

Blogs

• Runar Bjarnason, author of Functional Programming in Scala
• Rob Norris a.k.a. tpolecat, author of doobie
• Li Haoyi, author of ammonite
• Eric Torreborre, author of specs2
• Travis Brown, author of circe
• Typelevel, the blog of the typelevel organization
• Erik Bruchez