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

Function parameters and arguments


In our sample function definition given by the following code (Ch3_1.fsx):

let circleArea radius = 
  System.Math.PI * radius * radius 

The radius identifier represents the function parameter, that is, the name for a value that is expected to be transformed by the function. The value supplied for the parameter upon the function use represents the function argument, as shown when we apply our function in the following code line:

circleArea 15.0 

15.0 is the function's argument in the preceding line.

The tuples preview

At this point, in order to reveal the further details about function parameters, a certain notion would be required, which logically belongs to a completely different language facility, specifically to data types. I'm talking about tuples. As it doesn't seem feasible to build an ideally straight storyline, I will provide a necessary preview here and then revisit the subject of tuples in later chapters.

A tuple (https://msdn.microsoft.com/en-us/library...