haskell-wikibook

Getting set up Haskell Basics This chapter describes how to install the programs you'll need to start codin

Variables and functions (Solutions) Haskell Basics Getting set up Variables and functions Truth values Type ba

Truth values Haskell Basics [edit] In the last chapter, we used the equals sign to define variables and fun

Type basics (Solutions) Haskell Basics In programming, Types are used to group similar values into categori

Haskell uses two fundamental structures for managing several values: lists and tuples. They both work by grouping multip

Type basics II Haskell Basics In this chapter, we will show how numerical types are handled in Haskell and

Next steps (Solutions) Haskell Basics This chapter introduces pattern matching and two new pieces of syntax

Building vocabulary Haskell Basics This chapter will be a bit of an interlude with some advice for studying

Simple input and output (Solutions) Haskell Basics Back to the real world[edit] Beyond internally calculati

Recursion (Solutions) Elementary Haskell Recursion plays a central role in Haskell (and computer science an

Lists II (Solutions) Elementary Haskell Earlier, we learned that Haskell builds lists via the cons operator

Lists III (Solutions) Elementary Haskell Recursion Lists II (map) Lists III (folds, comprehensions) Type decla

Type declarations (Solutions) Elementary Haskell You're not restricted to working with just the types provi

Pattern matching (Solutions) Elementary Haskell In the previous modules, we introduced and made occasional

Control structures (Solutions) Elementary Haskell Haskell offers several ways of expressing a choice betwee

More on functions (Solutions) Elementary Haskell Here are several nice features that make using functions e

Higher-order functions (Solutions) Elementary Haskell At the heart of functional programming is the idea th

Using GHCi effectively Elementary Haskell GHCi assists in several ways toward more efficient work. Here, we

Modules Intermediate Haskell Modules are the primary means of organizing Haskell code. We met them in passi

Standalone programs Intermediate Haskell Let's build a simple Haskell application, i.e. a piece of standalo

Indentation (Solutions) Intermediate Haskell Haskell relies on indentation to reduce the verbosity of your

More on datatypes Intermediate Haskell Enumerations[edit] One special case of the data declaration is the e

Other data structures Intermediate Haskell In this chapter, we will work through examples of how the techni

Classes and types Intermediate Haskell Back in Type basics II we had a brief encounter with type classes as

The Functor class Intermediate Haskell In this chapter, we will introduce the important Functor type class.

Prologue: IO, an applicative functor Monads Prologue: IO, an applicative functor Understanding monads Maybe Li

Understanding monads Monads There is a certain mystique about monads, and even about the word "monad" itsel

Maybe Monads We introduced monads using Maybe as an example. The Maybe monad represents computations which

List (Solutions) Monads Lists are a fundamental part of Haskell, and we've used them extensively before get

do notation Monads Using do blocks as an alternative monad syntax was first introduced way back in the Simp

IO (Solutions) Monads Two defining features of Haskell are pure functions and lazy evaluation. All Haskell

State (Solutions) Monads If you have programmed in any other language before, you likely wrote some functio

Alternative and MonadPlus (Solutions) Monads Prologue: IO, an applicative functor Understanding monads Maybe L

Monad transformers (Solutions) Monads We have seen how monads can help handling IO actions, Maybe, lists, a

Monoids (Solutions) Advanced Haskell In earlier parts of the book, we have made a few passing allusions to

Applicative functors (Solutions) Advanced Haskell When covering the vital Functor and Monad type classes, w

Foldable (Solutions) Advanced Haskell The Foldable type class provides a generalisation of list folding (fo

Traversable (Solutions) Advanced Haskell We already have studied four of the five type classes in the Prelu

Arrow tutorial Advanced Haskell Arrows provide an alternative to the usual way of structuring computations

Understanding arrows (Solutions) Advanced Haskell

Continuation passing style (Solutions) Advanced Haskell Monoids Applicative functors img Foldable Traversable

Zippers (Solutions) Advanced Haskell Theseus and the Zipper[edit] The Labyrinth[edit] "Theseus, we have to

Lenses and functional references (Solutions) Advanced Haskell This chapter is about functional references.

Mutable objects Advanced Haskell Functional purity is a defining characteristic of Haskell, one which leads

Concurrency (Solutions) Advanced Haskell Concurrency[edit] Concurrency in Haskell is mostly done with Haske

Polymorphism (Solutions) Fun with Types Parametric Polymorphism[edit] Section goal = short, enables reader

Existentially quantified types (Solutions) Fun with Types Polymorphism basics img Existentially quantified typ

Advanced type classes (Solutions) Fun with Types Type classes may seem innocuous, but research on the subje

Phantom types (Solutions) Fun with Types Phantom types are a way to embed a language with a stronger type s

img Wikipedia has related information at Generalized algebraic data type GADT (Solutions) Fun with Types

Kinds (Solutions) Fun with Types Polymorphism basics img Existentially quantified types img Advanced type clas

Category theory (Solutions) Wider Theory This article attempts to give an overview of category theory, in s

The Curry–Howard isomorphism (Solutions) Wider Theory Denotational semantics img Equational reasoning Program

Fix and recursion (Solutions) Wider Theory The fix function is a particularly weird-looking function when y

Performance introduction (Solutions) Haskell Performance Execution Model[edit] [edit] Programming is not on

Performance examples (Solutions) Haskell Performance Goal: Explain optimizations step by step with examples

Graph reduction (Solutions) Haskell Performance Notes and TODOs[edit] TODO: Pour lazy evaluation explanati

Laziness (Solutions) Haskell Performance “ Hard work pays off later. Laziness pays off now! – Steven Wrig

In every language, profiling is the first crucial step of performance optimization. Otherwise, it is difficult to unders

Strictness (Solutions) Haskell Performance [edit] Strict evaluation, or eager evaluation, is an evaluation

Algorithm complexity (Solutions) Haskell Performance Complexity Theory is the study of how long a program w

Libraries (Solutions) Libraries Reference Haskell has a rich and growing set of libraries. They fall into s

Maybe (Solutions) Libraries Reference The Maybe data is used with functions that might be unsuccessful. The

IO (Solutions) Libraries Reference The IO Library[edit] Here, we'll explore the most commonly used elements

Random (Solutions) Libraries Reference

Data structures primer Libraries Reference This chapter introduces some of the data structures available fr

Arrays (Solutions) Libraries Reference Haskell'98 supports just one array constructor type, namely Array, w

Maps Libraries Reference The module Data.Map provides the Map datatype, which allows you to store values at

Debugging General Practices [edit] Debug prints are a common way to debug programs. In imperative languages

Testing (Solutions) General Practices Quickcheck[edit] Consider the following function: getList = find 5

Packaging General Practices Debugging Testing Packaging your software (Cabal) Using the Foreign Function Inter

FFI (Solutions) General Practices Debugging Testing Packaging your software (Cabal) Using the Foreign Function

SYB (Solutions) General Practices Debugging Testing Packaging your software (Cabal) Using the Foreign Function

GUI (Solutions) Specialised Tasks Graphical user interfaces (GUI) img Databases img Working with XML img Parsi

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Database (Solutions) Specialised Tasks Introduction[edit] Haskell's most popular database module is HDBC. H

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XML (Solutions) Specialised Tasks There are several Haskell libraries for XML work, and additional ones for

ParseExps (Solutions) Specialised Tasks Graphical user interfaces (GUI) img Databases img Working with XML img

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Syntactic sugar refers to any redundant type of syntax in a programming language that is redundant to the main syntax bu

Solutions to exercises. If you have found an answer that isn't in these articles, but you're sure is correct (by testing

The Haskell wikibook combines original material with the content of some previously existing tutorials. We are extremely

See also: Category:Haskell/Stubs Cleanups[edit] Haskell/Other data structures - tricky one. While the discussion on

This page is an incubator for developing modules which for one reason or another (for instance, for requiring large-scal

Here is a non-exhaustive list of topics covered by the book modules (as of now, covering the first three chapters). Righ

what i would like is a meta-tutorial a list of questions about haskell, what does this do, do you understand this etc a

This portal points to places where you can go if you want to learn Haskell. The Introduction to Haskell on the Haskell

Version 2.3 % Stephen Diehl % March 2016 Stephen Diehl ( ) This is the fourth draft of this document. PDF Vers

img Haskell是一种函数式编程语言。如果学过编程，并想了解Haskell如何工作以及和其它编程语言有何不同，你可以看一下概述。 Haskell有两大特点。第一，它是纯函数性的。如果一个函数在不同的环境下以相同的参数调用两次，那么这两

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