Librería Portfolio

If you have an imperative (and probably object-oriented) programming background, this hands-on book will guide you through the alien world of functional programming. Author Joshua Backfield begins slowly by showing you how to apply the most useful implementation concepts before taking you further into functional-style concepts and practices.

In each chapter, you'll learn a functional concept and then use it to refactor the fictional XXY company's imperative-style legacy code, writing and testing the functional code yourself. As you progress through the book, you'll migrate from Java 7 to Groovy and finally to Scala as the need for better functional language support gradually increases.

Learn why today's finely tuned applications work better with functional code
Transform imperative-style patterns into functional code, following basic steps
Get up to speed with Groovy and Scala through examples
Understand how first-class functions are passed and returned from other functions
Convert existing methods into pure functions, and loops into recursive methods
Change mutable variables into immutable variables
Get hands-on experience with statements and nonstrict evaluations
Use functional programming alongside object-oriented design


Chapter 1: Introduction
Overview of Concepts in Functional Programming
Functional Programming and Concurrency
Conclusion
Chapter 2: First-Class Functions
Introduction to XXY
Functions as Objects
Anonymous Functions
Higher-Order Functions
Refactoring get Functions by Using Groovy
Conclusion
Chapter 3: Pure Functions
Output Depends on Input
Purifying Our Functions
Side Effects
Conclusion
Chapter 4: Immutable Variables
Mutability
Immutability
Conclusion
Chapter 5: Recursion
An Introduction to Recursion
Recursion
Tail Recursion
Refactoring Our countEnabledCustomersWithNoEnabledContacts Function
Conclusion
Chapter 6: Strict and Nonstrict Evaluations
Strict Evaluation
Nonstrict (Lazy) Evaluation
Laziness Can Create Problems
Conclusion
Chapter 7: Statements
Taking the Plunge
Simple Statements
Block Statements
Everything Is a Statement
Conclusion
Chapter 8: Pattern Matching
Simple Matches
Simple Patterns
Extracting Lists
Extracting Objects
Converting to Pattern Matches
Conclusion
Chapter 9: Functional OOP
Static Encapsulation
Objects As Containers
Code as Data
Conclusion
Chapter 10: Conclusion
From Imperative to Functional
New Design Patterns
Putting It All Together
Conclusion