Contents  i

 Preface  vii

1.1 Program Structure  3

1.2 The Haskell Kernel  4

1.3 Values and Types  4

1.4 Namespaces  5

2.1 Notational Conventions  7

2.2 Lexical Program Structure  8

2.3 Comments  9

2.4 Identifiers and Operators  10

2.5 Numerical Literals  11

2.6 Character and String Literals  12

2.7 Layout  13

3.1 Errors  19

3.2 Variables, Constructors, Operators, and Literals  20

3.3 Curried Applications and Lambda Abstractions  21

3.4 Operator Applications  21

3.5 Sections  22

3.6 Conditionals  23

3.7 Lists  23

3.8 Tuples  24

3.9 Unit Expressions and Parenthesized Expessions  25

3.10 Arithmetic Sequences  25

3.11 List Comprehensions  25

3.12 Let Expressions  27

3.13 Case Expressions  27

3.14 Do Expressions  29

3.15 Datatypes with Field Labels  29

3.16 Expression Type Signatures  32

3.17 Pattern Matching  32

4.1 Overview of Types and Classes  40

4.2 User-Defined datatypes  45

4.3 Type Classes and Overloading  49

4.4 Nested Declarations  55

4.5 Static Semantics of Function and Pattern Bindings  60

4.6 Kind Inference  66

5.1 Module Structure  68

5.2 Export Lists  69

5.3 Import Declarations  71

5.4 Importing and Exporting Instance Declarations  74

5.5 Name Clashes and Closure  74

5.6 Standard Prelude  77

5.7 Separate Compilation  78

5.8 Abstract Datatypes  78

6.1 Standard Haskell Types  81

6.2 Strict Evaluation  84

6.3 Standard Haskell Classes  84

6.4 Numbers  91

7.1 Standard I/O Functions  97

7.2 Sequencing I/O Operations  99

7.3 Exception Handling in the I/O Monad  100

8.1 Module Prelude  104

8.2 Module PreludeList  114

8.3 Module PreludeText  119

8.4 Module PreludeIO  123

9.1 Notational Conventions  125

9.2 Lexical Syntax  126

9.3 Layout  128

9.4 Literate Comments  131

9.5 Context-Free Syntax  133

10.1 Derived Instances of Eq and Ord  140

10.2 Derived Instances of Enum  140

10.3 Derived Instances of Bounded  141

10.4 Derived Instances of Read and Show  142

10.5 An Example  143

11.1 Inlining  145

11.2 Specialization  145

12.1 Library Ratio  150

13.1 Library Complex  154

14.1 Showing Functions  158

14.2 Reading Functions  159

14.3 Miscellaneous  159

14.4 Library Numeric  160

15.1 Deriving Instances of Ix  170

15.2 Library Ix  171

16.1 Array Construction  174

16.2 Incremental Array Updates  175

16.3 Derived Arrays  176

16.4 Library Array  176

17.1 Indexing Lists  181

17.2 “Set” Operations  181

17.3 List Transformations  182

17.4 unfoldr  182

17.5 Predicates  183

17.6 The “By” Operations  183

17.7 The “generic” Operations  184

17.8 Further “zip” Operations  184

17.9 Library List  184

18.1 Library Maybe  192

19.1 Library Char  195

20.1 Naming Conventions  200

20.2 Class MonadPlus  200

20.3 Functions  201

20.4 Library Monad  202