User:Lenny222/Haskell explained to the busy

You have heard about Haskell but don't have the time to find out what it is?

This page may be for you.

Introduction

What is Haskell?

Haskell is a purely functional, lazy, statically typed programming language

What is a purely functional programming language?

What is good about that?

What is a lazy programming language?

What is good about that?

What is a statically typed programming language

What is good about that?

Why the name "Haskell"?

Haskell is named after the American mathematician Haskell Curry

Basics

Question	Answer
What is the meaning of the double colon "::"?	TODO
What is the meaning of the square brackets "[" and "]"?	TODO
What is the meaning of the colon ":"?	":" is an infix operator that adds an element to the beginning of a list For example: 1 : [2,3] will result in the new list [1,2,3]
What is an infix operator?	Infix operators are normal functions. TODO: symbols, round brackets For example: 5 + 2 is the same as (+) 5 2
Are there any prefix operators?	TODO
What is the meaning of the backtick "`"?	A function enclosed in "`"s can be used as an infix operator. For example: subtract 2 10 is the same as 2 `subtract` 10
What is the meaning of the tick " ' "?	TODO: single characters, common usage in function names
How do you define a function in Haskell?	TODO For example: add x y = x + y
Didn't you say Haskell is statically typed?	It is. TODO
What is the meaning of the double dash "--"?	"-- " (a trailing space is necessary) begins a single-line comment. The rest of the line will be ignored by the compiler. For example: -- Sort the list sort [3,2,4] or sort [3,2,4] -- Sort the list
What is the meaning of "{-" and "-}"?	"{- " (a trailing space is necessary) and "-}" define a block comment. Everything in between will be ignored by the compiler. For example: {- The next line would sort the list, if it wasn't in a block comment sort [3,2,4] -}
What is the meaning of the dollar sign "$"?	"$" is a way to compose functions, but avoid typing too many brackets. For example: foo x = h (g (f x)) is the same as foo x = h $ g $ f x
What is the meaning of the dot "."?	"." is used to compose functions in point-free style, similar to "$". For example: foo x = h $ g $ f x is the same as foo = h . g . f
What is point-free style?	Point-free style is a way to define functions solely as a composition of other functions, leaving out arguments in the definition. For example: takeFive x = take 5 x is the same as takeFive = take 5 in point-free style.
What is the meaning of "data"?	"data" defines a new data type. TODO For example: data colors = Red | Blue | Green
What is the meaning of "deriving"?	TODO
What is the meaning of "newtype"?	TODO
What is the meaning of "type"?	TODO
What is currying?	TODO
What is pattern matching?	TODO
What is the meaning of the backslash "\"?	TODO: multiline strings, lambda function
What is the meaning of the downslash "¦"?	TODO: pattern matching, data types

Advanced

Question	Answer
What is the meaning of "{-#" and "#-}"?	"{-# " (the trailing space is necessay) and "#-}" define compiler pragmas. TODO
What is a Monad?	TODO
What is the meaning of "forall"?	TODO