Beginning Scala 3 A Functional and Object-Oriented Java Language

• Main Author: David Pollak, Vishal Layka, Andres Sacco
• Format: eBook
• Language: English
• Published: Berkeley, CA Apress 2022; Apress L. P
• Edition: 3
• Subjects: Computer Science; Computer Science, general; COMPUTERS; Java; Professional and Applied Computing; Professional Computing; Scala (Computer program language); Software Engineering/Programming and Operating Systems

Learn the latest version of Scala through simple, practical examples. This book introduces you to the Scala programming language, its object-oriented and functional programming characteristics, and then guides you through Scala constructs and libraries that allow you to assemble small components int...

Table of Contents:

• Chapter 14: Scala Best Practices -- General Best Practices -- Recognizing the Functional Style -- Writing Pure Functions -- Leveraging Type Inferencing -- Think Expressions -- Focusing on Immutability -- Keeping Methods Short -- Using Options Instead of Null Testing -- Refactor Mercilessly -- Composing Functions and Classes -- Summary -- Index
• Intro -- Table of Contents -- About the Authors -- About the Technical Reviewer -- Acknowledgments -- Introduction -- Chapter 1: Getting Started with Scala -- Why Use Scala? -- Migrating to Scala 3 -- History -- Installing Scala Tools -- Installing Java JDK -- Installing Scala -- Using Brew -- Using Coursier -- Installing SBT -- Installing the IDE -- Running Code Examples -- Using an IDE -- Manually Using the REPL -- Running Little Blocks -- Compiling and Running Files -- Online Tools -- Summary -- Chapter 2: Basics of Scala -- Variables -- Scala Type Hierarchy -- Any, AnyVal, and AnyRef Types -- Numeric Types -- Types and Range -- Conversion -- Format -- Boolean -- Char -- Unit -- Strings -- Interpolation -- Compare -- Split -- Replace -- Special Characters -- Other Methods -- Date -- Format -- Arrays -- Lists -- Null -- Nothing -- Functions -- Control Structures -- if/then/else Expressions -- for Loops -- while Loops -- match Expressions -- try/catch/finally Blocks -- Comments -- Running Code Without the REPL -- Keywords -- Summary -- Chapter 3: Object-Oriented Modeling -- Concepts of OOP -- From Concepts to Concrete Things -- Classes -- Fields -- Constructors -- Visibility of the Fields -- Auxiliary Constructors -- Providing Default Values -- Private Constructor -- Methods -- Order -- Invoking Methods -- Override Default Methods -- toString -- equals -- Inheritance -- Inner Classes -- Value Classes -- Packages and Imports -- Multiple Imports -- Exclude Class -- Objects -- Defining Singletons -- Companion Objects -- Static Factory -- Opaque Types -- Export Clauses -- Summary -- Chapter 4: Functional Programming -- What Is Functional Programming? -- Pure Functions -- Side Effects -- Referential Transparency -- Expression-Oriented Programming -- Functions, Lambdas, and Closures -- Function Literal/Anonymous Function
• First-Class Functions and Higher-Order Functions -- Functions as Variables -- Functions as Parameters -- Returning a Function -- Closure -- Partially Applied Functions -- Curried Functions -- Function Compositions -- Function Error Handling -- Tail Calls and Tail Call Optimization -- Call-by-Name, Call-by-Value, and General Laziness -- Functional Structures -- Sequence -- Maps -- Sets -- Tuples -- Options -- Instantiating -- Chained Methods -- Functional Operations -- Traversing -- Mapping -- Filtering -- Summary -- Chapter 5: Pattern Matching -- Basic Pattern Matching -- Matching Any Type -- Testing Data Types -- Pattern Matching in Lists -- Pattern Matching and Lists -- Compiler Optimization -- Tableswitch -- Lookupswitch -- Considerations -- Pattern Matching with the Matchable Trait -- Pattern Matching and Case Classes -- Nested Pattern Matching in Case Classes -- Pattern Matching as Functions -- Pattern Matching on Regular Expressions -- Object-Oriented and Functional Tensions -- Shape Abstractions -- Summary -- Chapter 6: Scala Collections -- Scala Collection Hierarchy -- The scala.collection Package -- Sequences -- Sets -- Map -- The scala.collection.immutable package -- Immutable Sequence -- Immutable Set -- Immutable Map -- The scala.collection.mutable package -- Using Immutable Collection Classes -- Vector -- List[T] -- Getting Functional -- Transformation -- Reduxio -- Look Ma, No Loops -- Range -- Stream or LazyList -- Tuples -- Map[K, V] -- Mutable Collections -- Mutable ArrayBuffer -- Mutable Queue -- Mutable Stack -- Performance of the Collections -- Summary -- Chapter 7: Traits and Enums -- Traits -- Using Traits as Mixins -- Traits and Class Hierarchies -- Conflicts of Method Names -- Limiting the Use of a Trait -- Limiting Access by Class -- Limiting Access by Method -- Type Parameters or Type Members -- Passing Parameters on Traits
• Enumerations -- Algebraic Data Types in Enums -- Union and Intersection Types -- Summary -- Chapter 8: Scala Type System -- Unified Type System -- Type Parameterization -- Variance -- Covariant Parameter Types -- Contravariant Parameter Types -- Invariant Parameter Types -- Rules of Variance -- Type Bounds -- Upper Type Bounds -- Lower Type Bounds -- Extension Methods -- Scala 2 Implicit Class -- Scala 3 Given/Using Clauses -- Implicit Conversions -- Givens and Imports -- Using Clauses -- Summary -- Chapter 9: Scala and Java Interoperability -- Scala at a Glance -- Translating Java Classes to Scala Classes -- Translating Java Imports into Scala Imports -- Translating Multiple Constructors -- JavaBean Specification-Compliant Scala Classes -- Java Interfaces and Scala Traits -- Java Static Members and Scala Objects -- Handling Exceptions -- Java Optional and Scala Option -- Use Java Collections in Scala -- Summary -- Chapter 10: DSL and Parser Combinator -- A Closer Look at DSLs -- Internal DSLs -- External DSLs -- Summary -- Chapter 11: Simple Build Tool -- Getting Started with SBT -- Why SBT? -- Installing SBT -- General Commands -- Creating a Hello World Project -- Project Structure -- build.sbt -- Project Folder -- Src Folder -- Build Definition -- LibraryDependencies and Resolvers -- Plugins -- Summary -- Chapter 12: Creating Web Applications -- Architecture Types -- Setting Up the Application -- Application Flow -- Router -- Controller -- Model -- View -- Rest Application -- Defining the Endpoints -- Layers in the Application -- Custom Error Handler -- Summary -- Chapter 13: Testing Your Code -- Testing with ScalaTest -- Writing Your First Test -- Ignoring the Execution of the Test -- Other Ways of Declaring the Test -- Using Matchers to Validate Results -- Tagging Your Test -- Before and After Methods -- Summary