Introduction

Haskell is quite an unusual language. But, despite the considerable number of articles on it, one can often come across the opinion that all this helps only in synthetic examples. Indeed, with simple examples, everything looks simple, but it is much harder to imagine at least a small program in this style, and articles often look at the peculiarities of the language. So I wanted to write a series of articles, during which we will explore the possibilities of the language and try to write a simple chat. Why just chat? Because there is a place and multithreading, and client GUI, and server database. Although I would love to listen to your suggestions, as I myself am wondering how this language is convenient for solving more complex problems.
So if you are interested in it, then I will risk it.

The basics
Data Types, Pattern Matching, and Functions
Classes of types, monads