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

Exploring quotations and metaprogramming


The last feature I want to cover among the advanced patterns of F# use is Code Quotations (https://docs.microsoft.com/en-us/dotnet/articles/fsharp/language-reference/code-quotations). This feature is quite mind-bending, allowing you to work with the program code as if it is data, and evaluate these "program as data" pieces when needed and in the needed manner.

The feature review

Looking at this feature from the more operational angle, a program piece may be represented as an expression tree representing the code but without running the code generation off this representation. This allows for arbitrary execution behavior when the expression tree is to be evaluated. It can be evaluated as F# code or as source to generate JavaScript code or even as GPU-executed code or in any other feasible manner.

The cool thing about quoted expressions is that they are typed, they can be spliced together from parts, or they can be decomposed into parts using active patterns...