Book Image

F# 4.0 Design Patterns

By : Gene Belitski
Book Image

F# 4.0 Design Patterns

By: Gene Belitski

Overview of this book

Following design patterns is a well-known approach to writing better programs that captures and reuses high-level abstractions that are common in many applications. This book will encourage you to develop an idiomatic F# coding skillset by fully embracing the functional-first F# paradigm. It will also help you harness this powerful instrument to write succinct, bug-free, and cross-platform code. F# 4.0 Design Patterns will start off by helping you develop a functional way of thinking. We will show you how beneficial the functional-first paradigm is and how to use it to get the optimum results. The book will help you acquire the practical knowledge of the main functional design patterns, the relationship of which with the traditional Gang of Four set is not straightforward. We will take you through pattern matching, immutable data types, and sequences in F#. We will also uncover advanced functional patterns, look at polymorphic functions, typical data crunching techniques, adjusting code through augmentation, and generalization. Lastly, we will take a look at the advanced techniques to equip you with everything you need to write flawless code.
Table of Contents (20 chapters)
F# 4.0 Design Patterns
Credits
About the Author
Acknowledgements
About the Reviewer
www.PacktPub.com
Preface

The sequence: Duality of data and calculation


What makes the F# sequence so ambient and versatile is its dual nature. Being a strongly typed generic data collection, it exposes the contained data via two archetypal .NET interfaces of the System.Collections.Generic namespace, namely IEnumerable<T> (https://msdn.microsoft.com/en-us/library/9eekhta0(v=vs.110).aspx) and IEnumerator<T> (https://msdn.microsoft.com/en-us/library/78dfe2yb(v=vs.110).aspx).

These interfaces personify the classic data pull protocol, where a data consumer actively pulls data from the producer. Indeed, the type of seq<'T> in the F# is defined as the following abbreviation:

type seq<'T> = System.Collections.Generic.IEnumerable<'T> 

The preceding line of code means in practice that each F# sequence is a data collection, which can be traversed by getting an enumerator that allows you to stir through the sequence from its head towards its tail, obtaining the values of its elements. The enumerator...