Add "Domain Modeling Made Functional" book reference and cover image

Author: IanWitham

learn/files/BookDMMF.png

@@ -131,6 +131,20 @@ Everywhere you look, programming languages are gaining functional features. The
 
 This book started life as a series of blog posts on my Company's website (https://www.softwarepark.cc/blog). The sum of the content is what a developer needs to know to be able to work on one of our F# Line of Business codebases. I have improved and extended the content, upgraded the code to F# 5 and ensured that the code will run in VS Code.
 
+### [Domain Modeling Made Functional](https://pragprog.com/titles/swdddf/domain-modeling-made-functional/)
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+<img src="/learn/files/BookDMMF.png" width=100 height=120 style="float:right;margin:5px 0px 5px 25px;" />
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+_Scott Wlaschin_
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+You want increased customer satisfaction, faster development cycles, and less wasted work. Domain-driven design (DDD) combined with functional programming is the innovative combo that will get you there. In this pragmatic, down-to-earth guide, you’ll see how applying the core principles of functional programming can result in software designs that model real-world requirements both elegantly and concisely—often more so than an object-oriented approach. Practical examples in the open-source F# functional language, and examples from familiar business domains, show you how to apply these techniques to build software that is business-focused, flexible, and high quality.
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+Domain-driven design is a well-established approach to designing software that ensures that domain experts and developers work together effectively to create high-quality software. This book is the first to combine DDD with techniques from statically typed functional programming. This book is perfect for newcomers to DDD or functional programming—all the techniques you need will be introduced and explained.
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+Model a complex domain accurately using the F# type system, creating compilable code that is also readable documentation—ensuring that the code and design never get out of sync. Encode business rules in the design so that you have “compile-time unit tests,” and eliminate many potential bugs by making illegal states unrepresentable. Assemble a series of small, testable functions into a complete use case, and compose these individual scenarios into a large-scale design. Discover why the combination of functional programming and DDD leads naturally to service-oriented and hexagonal architectures. Finally, create a functional domain model that works with traditional databases, NoSQL, and event stores, and safely expose your domain via a website or API.
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+Solve real problems by focusing on real-world requirements for your software.
+
 ### [F# Programming Wikibook](http://en.wikibooks.org/wiki/Programming:F_Sharp)
 
 The wikibook contains a comprehensive guide to F# programming. It covers