Programming Scala: Scalability = Functional Programming + Objects, 3rd Edition

https://musicboxcle.com/2025/04/db3c4lanyef Foreword Foreword, Third Edition Foreword, First and Second Edition Preface Welcome to Programming Scala, Third Edition How to Read This Book Welcome to Programming Scala, Second Edition Welcome to Programming Scala, First Edition Conventions Used in This Book Using Code Examples Getting the Code Examples O’Reilly Online Learning How to Contact Us Acknowledgments for the Third Edition Acknowledgments for the Second Edition Acknowledgments for the First Edition 1. Zero to Sixty: Introducing Scala Why Scala? The Appeal of Scala Why Scala 3? Migrating to Scala 3 Installing the Scala Tools You Need Building the Code Examples More Tips Using sbt Running the Scala Command-Line Tools Using sbt A Taste of Scala A Sample Application Recap and What’s Next 2. Type Less, Do More New Scala 3 Syntax—Optional Braces Semicolons Variable Declarations Ranges Partial Functions Method Declarations Method Default and Named Parameters Methods with Multiple Parameter Lists A Taste of Futures Nesting Method Definitions and Recursion Inferring Type Information Repeated Parameter Lists Language Keywords Literal Values Numeric Literals Boolean Literals Character Literals String Literals Symbol Literals Function Literals Tuples Option, Some, and None: Avoiding Nulls When You Really Can’t Avoid Nulls Sealed Class Hierarchies and Enumerations Organizing Code in Files and Namespaces Importing Types and Their Members Package Imports and Package Objects Parameterized Types Versus Abstract Type Members Recap and What’s Next 3. Rounding Out the Basics Defining Operators Allowed Characters in Identifiers Methods with Empty Parameter Lists Operator Precedence Rules Enumerations and Algebraic Data Types Interpolated Strings Scala Conditional Expressions Conditional and Comparison Operators for Comprehensions for Loops Generators Guards: Filtering Values Yielding New Values Expanded Scope and Value Definitions Scala while Loops Using try, catch, and finally Clauses Call by Name, Call by Value Lazy Values Traits: Interfaces and Mixins in Scala When new Is Optional Recap and What’s Next 4. Pattern Matching Safer Pattern Matching with Matchable Values, Variables, and Types in Matches Matching on Sequences Pattern Matching on Repeated Parameters Matching on Tuples Parameter Untupling Guards in Case Clauses Matching on Case Classes and Enums Matching on Regular Expressions Matching on Interpolated Strings Sealed Hierarchies and Exhaustive Matches Chaining Match Expressions Pattern Matching Outside Match Expressions Problems in Pattern Bindings Pattern Matching as Filtering in for Comprehensions Pattern Matching and Erasure Extractors unapply Method Alternatives to Option Return Values unapplySeq Method Implementing unapplySeq Recap and What’s Next 5. Abstracting Over Context: Type Classes and Extension Methods Four Changes Extension Methods Build Your Own String Interpolator Type Classes Scala 3 Type Classes Alias Givens Scala 2 Type Classes Scala 3 Implicit Conversions Type Class Derivation Givens and Imports Givens Scoping and Pattern Matching Resolution Rules for Givens and Extension Methods The Expression Problem Recap and What’s Next 6. Abstracting Over Context: Using Clauses Using Clauses Context Bounds Other Context Parameters Context Functions Constraining Allowed Instances Implicit Evidence Working Around Type Erasure with Using Clauses Rules for Using Clauses Improving Error Messages Recap and What’s Next 7. Functional Programming in Scala What Is Functional Programming? Functions in Mathematics Variables That Aren’t Functional Programming in Scala Anonymous Functions, Lambdas, and Closures Methods as Functions Purity Inside Versus Outside Recursion Tail Calls and Tail-Call Optimization Partially Applied Functions Versus Partial Functions Currying and Uncurrying Functions Tupled and Untupled Functions Partial Functions Versus Functions Returning Options Functional Data Structures Sequences Maps Sets Traversing, Mapping, Filtering, Folding, and Reducing Traversing Mapping Flat Mapping Filtering Folding and Reducing Left Versus Right Folding Combinators: Software’s Best Component Abstractions What About Making Copies? Recap and What’s Next 8. for Comprehensions in Depth Recap: The Elements of for Comprehensions for Comprehensions: Under the Hood Translation Rules of for Comprehensions Options and Container Types Option as a Container? Either: An Alternative to Option Throwing exceptions versus returning either values Try: When There Is No Do Validated from the Cats Library Recap and What’s Next 9. Object-Oriented Programming in Scala Class and Object Basics: Review Open Versus Closed Types Classes Open for Extension Overriding Methods? The Template Method Pattern Reference Versus Value Types Opaque Types and Value Classes Opaque Type Aliases Opaque type aliases and matchable Value Classes Supertypes Constructors in Scala Calling Supertype Constructors Export Clauses Good Object-Oriented Design: A Digression Fields in Types The Uniform Access Principle Unary Methods Recap and What’s Next 10. Traits Traits as Mixins Stackable Traits Union and Intersection Types Transparent Traits Using Commas Instead of with Trait Parameters Should That Type Be a Class or Trait? Recap and What’s Next 11. Variance Behavior and Equality Parameterized Types: Variance Under Inheritance Functions Under the Hood Variance of Mutable Types Improper Variance of Java Arrays Equality of Instances The equals Method The == and != Methods The eq and ne Methods Array Equality and the sameElements Method Equality and Inheritance Multiversal Equality Case Objects and hashCode Recap and What’s Next 12. Instance Initialization and Method Resolution Linearization of a Type Hierarchy Initializing Abstract Fields Overriding Concrete Fields Abstract Type Members and Concrete Type Aliases Recap and What’s Next 13. The Scala Type Hierarchy Much Ado About Nothing (and Null) The scala Package Products, Case Classes, Tuples, and Functions Tuples and the Tuple Trait The Predef Object Implicit Conversions Type Definitions Condition Checking Methods Input and Output Methods Miscellaneous Methods Recap and What’s Next 14. The Scala Collections Library Different Groups of Collections Abstractions with Multiple Implementations The scala.collection.immutable Package The scala.collection.mutable Package The scala.collection Package The scala.collection.concurrent Package The scala.collection.convert Package The scala.collection.generic Package Construction of Instances The Iterable Abstraction Polymorphic Methods Equality for Collections Nonstrict Collections: Views Recap and What’s Next 15. Visibility Rules Public Visibility: The Default Visibility Keywords Protected Visibility Private Visibility Scoped Private and Protected Visibility Recap and What’s Next 16. Scala’s Type System, Part I Parameterized Types Abstract Type Members and Concrete Type Aliases Comparing Abstract Type Members Versus Parameterized Types Type Bounds Upper Type Bounds Lower Type Bounds Context Bounds View Bounds Intersection and Union Types Intersection Types Rules for intersection types Union Types Rules for union types Rules for union and intersection types together Phantom Types Structural Types Refined Types Existential Types (Obsolete) Recap and What’s Next 17. Scala’s Type System, Part II Match Types Dependently Typed Methods Dependent Method and Dependent Function Types Dependent Typing Path-Dependent Types Using this Using super Stable Paths Self-Type Declarations Type Projections More on Singleton Types Self-Recursive Types: F-Bounded Polymorphism Higher-Kinded Types Type Lambdas Polymorphic Functions Type Wildcard Versus Placeholder Recap and What’s Next 18. Advanced Functional Programming Algebraic Data Types Sum Types Versus Product Types Properties of Algebraic Data Types Final Thoughts on Algebraic Data Types Category Theory What Is a Category? Functor The Monad Endofunctor The Semigroup and Monoid Categories Recap and What’s Next 19. Tools for Concurrency The scala.sys.process Package Futures Robust, Scalable Concurrency with Actors Akka: Actors for Scala Actors: Final Thoughts Stream Processing Recap and What’s Next 20. Dynamic Invocation in Scala Structural Types Revisited A Motivating Example: ActiveRecord in Ruby on Rails Dynamic Invocation with the Dynamic Trait DSL Considerations Recap and What’s Next 21. Domain-Specific Languages in Scala Internal DSLs External DSLs with Parser Combinators About Parser Combinators A Payroll External DSL Internal Versus External DSLs: Final Thoughts Recap and What’s Next 22. Scala Tools and Libraries Scala 3 Versions Command-Line Interface Tools Coursier Managing Java JDKs with Coursier The scalac Command-Line Tool The scala Command-Line Tool The scaladoc Command-Line Tool Other Scala Command-Line Tools Build Tools Integration with IDEs and Text Editors Using Notebook Environments with Scala Testing Tools Scala for Big Data: Apache Spark Typelevel Libraries Li Haoyi Libraries Java and Scala Interoperability Using Java Identifiers in Scala Code Scala Identifiers in Java Code Java Generics and Scala Parameterized Types Conversions Between Scala and Java Collections Java Lambdas Versus Scala Functions Annotations for JavaBean Properties and Other Purposes Recap and What’s Next 23. Application Design Recap of What We Already Know Annotations Using @main Entry Points Design Patterns Creational Patterns Structural Patterns Behavioral Patterns Better Design with Design by Contract The Parthenon Architecture Recap and What’s Next 24. Metaprogramming: Macros and Reflection Scala Compile Time Reflection Java Runtime Reflection Scala Reflect API Type Class Derivation: Implementation Details Scala 3 Metaprogramming Inline Macros Staging Wrapping Up and Looking Ahead A. Significant Indentation Versus Braces Syntax Bibliography Index