I.The Language	7
1.What is Haskell?	9
Functional Programming Concepts 	9
Values 	9
Expressions 	9
Functions and Parameters 	9
Recursion 	9
Functions as Values 	9
Strictness vs. Laziness 	10
A Comparison with Procedural and Object-Oriented Languages 	10
A Comparison with Other Functional Languages 	10
2.Using Haskell Code	11
Using a Haskell Interpreter: HUGS 	11
Using a Haskell Compiler: GHC 	11
Using Haskell with Web Servers 	11
Using Haskell for CGI 	11
Using Haskell with mod_haskell 	11
3.Values and Expressions	13
Values 	13
Literals 	13
Names 	13
Expressions and Precedence 	13
Calling Functions 	13
Expressions that Produce Functions 	14
"Changing State" by Creating New Values 	14
4.Naming your Expressions	15
Naming an Expression 	15
The Basic Syntax 	15
Layout 	15
Using C-style Braces and Semicolons 	15
Reusing a Named Expression 	15
Why We Haven't Mentioned Types Yet 	15
Inferring a Type 	15
The Type of a Function 	16
Telling Haskell the Type When It Can't Figure It Out 	16
5.Defining Your Own Operators	17
Defining an Operator 	17
Setting Precedence 	17
Operators are Just Syntactic Sugar 	17
6.HaSh, or Using Haskell for a Shell	19
Hugs: A Calculator on Steroids 	19
The Prelude: All the Usual Suspects 	19
Loading Other Modules 	19
Handling IO with White Gloves 	19
Laziness - Change Nothing Until It Must 	19
Using >>=, >>, and return 	20
A Little Formalism: The Class "Monad" 	20
Haskell as a Shell 	20
File IO 	20
Shell Commands 	20
7.Software Engineering	21
Using Modules 	21
Exports 	21
Imports 	21
Using Classes 	21
Defining a Class 	21
Defining an Instance 	21
Deriving a Class 	21
II.A Brief Cookbook	23
8.Grep	25
Our Specification: Simple Grep 	25
Command-line Parameters 	25
File Manipulation 	25
Searching and Outputting Results 	25
9.A JPEG Codec and Browser	27
Our Specification: JPEG file formats and OpenGL Display 	27
A Desecription of JPEG 	27
Encoding (Hint - the description is the code) 	27
Decoding 	27
An External Library: OpenGL 	27
10.Database Access	29
Our Specification: Web Logs in SQL Databases 	29
Parsing the Log File 	29
Parsing Web-Search-Style Queries 	29
Data Mining 	29
III.The Libraries	31
11.Array	33
Exports 	33
From This Module 	33
From Others 	33
Classes 	33
Types and Constructor 	33
Instances 	33
Functions and Operators 	34
12.Char	35
Exports 	35
From This Module 	35
From Others 	35
Classes 	35
Types and Constructor 	35
Instances 	35
Functions and Operators 	36
13.Complex	37
Exports 	37
From This Module 	37
From Others 	37
Classes 	37
Types and Constructor 	37
Instances 	37
Functions and Operators 	38
14.IO	39
Exports 	39
From This Module 	39
From Others 	39
Classes 	39
Types and Constructor 	39
Instances 	39
Functions and Operators 	40
15.Ix	41
Exports 	41
From This Module 	41
From Others 	41
Classes 	41
Types and Constructor 	41
Instances 	41
Functions and Operators 	42
16.List	43
Exports 	43
From This Module 	43
From Others 	43
Classes 	43
Types and Constructor 	43
Instances 	43
Functions and Operators 	44
17.Locale	45
Exports 	45
From This Module 	45
From Others 	45
Classes 	45
Types and Constructor 	45
Instances 	45
Functions and Operators 	46
18.Maybe	47
Exports 	47
From This Module 	47
From Others 	47
Classes 	47
Types and Constructor 	47
Instances 	47
Functions and Operators 	48
19.Monad	49
Exports 	49
From This Module 	49
From Others 	49
Classes 	49
Types and Constructor 	49
Instances 	49
Functions and Operators 	50
20.Numeric	51
Exports 	51
From This Module 	51
From Others 	51
Classes 	51
Types and Constructor 	51
Instances 	51
Functions and Operators 	52
21.Prelude	53
Exports 	53
From This Module 	53
From Others 	53
Classes 	53
Types and Constructor 	53
Instances 	53
Functions and Operators 	54
22.Random	55
Exports 	55
From This Module 	55
From Others 	55
Classes 	55
Types and Constructor 	55
Instances 	55
Functions and Operators 	56
23.Ratio	57
Exports 	57
From This Module 	57
From Others 	57
Classes 	57
Types and Constructor 	57
Instances 	57
Functions and Operators 	58
24.System	59
Exports 	59
From This Module 	59
From Others 	59
Classes 	59
Types and Constructor 	59
Instances 	59
Functions and Operators 	60