Learn Haskell Fast and Hard

I really believe all developers should learn Haskell. I don’t think everyone needs to be super Haskell ninjas, but they should at least discover what Haskell has to offer. Learning Haskell opens your mind. Mainstream languages share the same foundations: variablesloopspointersdata structures, objects and classes (for most) Haskell is very different. But learning Haskell can be hard. This article will certainly be hard to follow. The conventional method to learning Haskell is to read two books. In contrast, this article is a very brief and dense overview of all major aspects of Haskell. The article contains five parts: Introduction: a short example to show Haskell can be friendly.Basic Haskell: Haskell syntax, and some essential notions.Hard Difficulty Part: Functional style; a progressive example, from imperative to functional styleTypes; types and a standard binary tree exampleInfinite Structure; manipulate an infinite binary tree! 01_basic/10_Introduction/00_hello_world.lhs Introduction ou

Haskell for all You Could Have Invented Monads! (And Maybe You Already Have.) If you hadn't guessed, this is about monads as they appear in pure functional programming languages like Haskell. They are closely related to the monads of category theory, but are not exactly the same because Haskell doesn't enforce the identities satisfied by categorical monads. Writing introductions to monads seems to have developed into an industry. There's a gentle Introduction, a Haskell Programmer's introduction with the advice "Don't Panic", an introduction for the "Working Haskell Programmer" and countless others that introduce monads as everything from a type of functor to a type of space suit. But all of these introduce monads as something esoteric in need of explanation. Many of the problems that monads try to solve are related to the issue of side effects. Side Effects: Debugging Pure Functions In an imperative programming language such as C++, functions behave nothing like the functions of mathematics. f,g :: Float -> Float f',g' :: Float -> (Float,String) which implies that

Haskell for all: Introductions to advanced Haskell topics Many people bemoan the sharp divide between experts and beginning Haskell programmers. One thing I've noticed is that "advanced" Haskell topics all have one thing in common: there exists only one good tutorial on that topic and only the experts have found it. This post is a collection of links to what I consider to be the definitive tutorials on these topics. Monads Monads are technically not an advanced Haskell topic, but I include this topic in the list because the vast majority of monad tutorials are terrible and/or misleading. In my opinion, the best monad tutorial (Titled: "You could have invented monads") was written 8 years ago by Dan Piponi and nobody has ever improved on it since. Monad Transformers One thing that perpetually boggles me is that the blogosphere has almost no posts explaining how to use monad transformers. Parsing Outsiders comment that monads only exist to paper over Haskell's weaknesses until they discover monadic parsers. Free Monads Coroutines Lenses Church encoding