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

Addressing some compile-time problems


Although REPL can help explore and tweak correct F# code, it keeps compiler errors intact, as evaluating a code snippet includes compilation by the F# compiler embedded into fsi. And I must admit that some compile-time errors may puzzle an inexperienced F# developer. Here, I will analyze several kinds of such errors and provide advice on how to get rid of them. Before I do this, you should keep in mind that because an initial defect usually gets ingested by type inference as correct code, the reported compilation error is in line with that convoluted type inference determination. That is, type inference often masks the authentic cause of an error. We will go over some occasions of this layout soon.

The if-then return value

One of the easiest-to-grasp occurrences of the similar convoluted determination takes place for the result type of F# if...then... expressions. Usually, it seems counterintuitive that this result cannot be anything but unit. Let's look...