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 alternative syntax for anonymous function performing matching


F# offers a special syntax to define anonymous functions that perform matching, or pattern matching functions (https://docs.microsoft.com/en-us/dotnet/articles/fsharp/language-reference/match-expressions).

This syntax assumes that the anonymous function has a single parameter that is placed at the beginning of the function body in the invisible match construction. Having this alternative way of defining pattern matching anonymous functions just adds to the language succinctness and also better reflects the intent behind defining such kind of functions within the code.

Continuing with coding exercises, in the latest F# script I will rewrite the validate function using the alternative syntax. However, to achieve this, it is required that you address the following problem. The alternative syntax assumes that the pattern matching function has a single argument, while validate has a pair of arguments. The way out would be to apply...