Practical functional C#

Retired

This book is no longer available for sale.

Practical functional C#

A practical guide to the language-ext C# functional Library

About the Book

This book is focused on the practical use of language-ext functional library in C#. We will break down the Sample projects and see where functional programming fits in modern Web Application development using Asp.Net Core and Domain Driven Design .

dotnetfiddle:https://dotnetfiddle.net/Authors/120678/dimitrispapadim

Github : https://github.com/dimitris-papadimitriou-chr/Practical-Functional-CSharp

This is a substantial Reduction of the book "Functional Programming in C#with Categories"

About the Author

dimitris papadimitriou
dimitris papadimitriou

I have more than 14 years’ experience as full stack developer and Architect.

I Like to stay in touch with all the latest developments in the field, as well as the foundational Theoretical Computer science and algorithm Analysis and Design

https://www.linkedin.com/in/dimitrispapadimitriou/

Table of Contents

  • 1 Language Functional support
    • 1.1 Pure functions and Side effects ... 5
    • 1.2 Evolution of Delegates in C# ... 8
    • 1.3 Higher-Order Functions /Functions as Data ... 11
    • 1.4 Named parameters and Tuples ... 12
    • 1.4.1 Lambda expressions and tuples ... 14
    • 1.5 Extension Methods ... 16
    • 1.6 Using static directive ... 17
    • 1.7 LINQ support for custom Data structures ... 19
    • 1.8 Currying and partial application ... 19
    • 1.9 The language-ext C# library ... 21
    • 1.9.1 Void is not a real type ... 21
    • 1.9.2 Immutable record types ... 22
  • 2 Functors
    • 2.1 The Identity Functor ... 23
    • 2.2 Which Map methods qualify as Valid ... 24
    • 2.3 List Functor ... 25
    • 2.4 Pattern Matching ... 25
    • 2.5 Folds ... 29
    • 2.5.1 The Basic Functor Mechanics ... 32
    • 2.6 Extending Task to Functor ... 33
    • 2.7 LINQ Native Query syntax: Functor Support ... 34
    • 2.7.1 Using the Linq syntax with Task ... 35
    • 2.8 Maybe Functor aka Option ... 36
    • 2.8.1 Dealing with null ... 36
    • 2.8.2 The Null Object Design pattern ... 36
    • 2.8.3 The Functional equivalent - Maybe as Functor ... 37
    • 2.8.4 Maybe Functor Example ... 40
    • 2.8.5 Maybe in Language-ext / Option ... 41
    • 2.8.6 Maybe Functor Example With language-ext Option ... 42
    • 2.8.7 Folding Maybe ... 43
    • 2.8.8 Using the Linq syntax ... 43
    • 2.9 Either Functor ... 44
    • 2.9.1 Pattern matching for Either ... 45
    • 2.9.2 Using C# 8.0 pattern matching ... 46
    • 2.9.3 Either Functor Example ... 46
    • 2.9.4 Either in Language-ext ... 47
    • 2.9.5 Using Either for exception handling ... 48
    • 2.10 Explicitly Compositing Functor ... 51
    • 2.11 Combining Task and Option – Task> ... 53
    • 2.12 Combining Task and Option – OptionAsync ... 55
    • 2.13 Combining Task and Either – Task> ... 56
    • 2.14 Combining Task and Either – EitherAsync<> ... 58
  • 3 Monads
    • 3.1 The List as a Monad ... 62
    • 3.2 The Identity Monad ... 63
    • 3.3 Maybe Monad ... 64
    • 3.3.1 Using language-ext Option ... 66
    • 3.3.2 Using the LINQ syntax with Option Monad ... 67
    • 3.4 Either Monad ... 68
    • 3.4.1 Using Either Monad for exception handling ... 68
    • 3.4.2 Using language-ext Either ... 69
    • 3.4.3 Using the LINQ syntax with Either Monad ... 70
    • 3.4.4 Using Either for Validation ... 71
    • 3.5 Validation Monad ... 71
    • 3.5.1 Using Validation.Apply to Collect validations ... 72
    • 3.5.2 Conversion Between Either and Validation ... 72
    • 3.6 Task as Monad ... 72
    • 3.7 The Task - Option Monad Combination -Task> ... 73
    • 3.8 The Task - Option Monad Combination -OptionAsync<> ... 75
    • 3.9 The Task - Either Monad Combination -Task> ... 77
    • 3.10 The Task - Either Monad Combination -EitherAsync<> ... 79
  • 4 A Clean Functional Architecture Example
    • 4.1 Download and Setup the Project ... 81
    • 4.2 Evolution of Software Architecture ... 81
    • 4.2.1 Layered Architecture ... 82
    • 4.2.2 Clean Architecture with .NET core ... 82
    • 4.3 A Functional Applications Architecture ... 83
    • 4.4 The Contoso Clean Architecture with .NET core and language-ext ... 84
    • 4.4.1 A list of Patterns and Practices ... 85
    • 4.5 Web Api ... 85
    • 4.6 Domain Model ... 87
    • 4.6.1 Repositories ... 89
    • 4.7 CQRS ... 90
    • 4.8 CQRS and MediatR ... 92
    • 4.8.1 The Command Pattern with a Mediator ... 92
    • 4.8.2 Query Workflow ... 95
    • 4.8.3 Command Workflow ... 98

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