Book Image

Learning C++ Functional Programming

By : Wisnu Anggoro
5 (1)
Book Image

Learning C++ Functional Programming

5 (1)
By: Wisnu Anggoro

Overview of this book

Functional programming allows developers to divide programs into smaller, reusable components that ease the creation, testing, and maintenance of software as a whole. Combined with the power of C++, you can develop robust and scalable applications that fulfill modern day software requirements. This book will help you discover all the C++ 17 features that can be applied to build software in a functional way. The book is divided into three modules—the first introduces the fundamentals of functional programming and how it is supported by modern C++. The second module explains how to efficiently implement C++ features such as pure functions and immutable states to build robust applications. The last module describes how to achieve concurrency and apply design patterns to enhance your application’s performance. Here, you will also learn to optimize code using metaprogramming in a functional way. By the end of the book, you will be familiar with the functional approach of programming and will be able to use these techniques on a daily basis.
Table of Contents (15 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Lazy evaluation in action


Having discussed the basic concept of lazy evaluation, let's dig into lazy evaluation by designing the code in the lazy approach. In this section, we will develop an eager evaluation code first, then refactor that code into the lazy evaluation one. The code we develop will generate a sequence of prime numbers. First, we will use the for loop to iterate the integer number to obtain the prime number in the eager evaluation. The following prime.cpp code is what we are talking about:

    /* prime.cpp */
    #include <iostream>
    #include <cmath>

    using namespace std;

    bool PrimeCheck(int i)
    {
      // All even numbers are not prime number
      // except 2
      if ((i % 2) == 0)
      {
        return i == 2;
      }

      // Calculating the square root of i
      // and store in int data type variable
      // if the argument i is not even number,
      int sqr = sqrt(i);

      // For numbers 9 and below,
      // the prime numbers is simply...