Date: 2010-07-20 13:11:00

Haskell 2010
Language Report

Simon Marlow
(editor)

Copyright notice.

The authors and publisher intend this Report to belong to the entire Haskell community, and grant permission to copy and distribute it for any purpose, provided that it is reproduced in its entirety, including this Notice. Modified versions of this Report may also be copied and distributed for any purpose, provided that the modified version is clearly presented as such, and that it does not claim to be a definition of the language Haskell 2010.

Contents
Preface
Goals
Haskell 2010: language and libraries
Extensions to Haskell 98
Haskell Resources
Building the language
I The Haskell 2010 Language
1 Introduction
1.1 Program Structure
1.2 The Haskell Kernel
1.3 Values and Types
1.4 Namespaces
2 Lexical Structure
2.1 Notational Conventions
2.2 Lexical Program Structure
2.3 Comments
2.4 Identifiers and Operators
2.5 Numeric Literals
2.6 Character and String Literals
2.7 Layout
3 Expressions
3.1 Errors
3.2 Variables, Constructors, Operators, and Literals
3.3 Curried Applications and Lambda Abstractions
3.4 Operator Applications
3.5 Sections
3.6 Conditionals
3.7 Lists
3.8 Tuples
3.9 Unit Expressions and Parenthesized Expressions
3.10 Arithmetic Sequences
3.11 List Comprehensions
3.12 Let Expressions
3.13 Case Expressions
3.14 Do Expressions
3.15 Datatypes with Field Labels
3.16 Expression Type-Signatures
3.17 Pattern Matching
4 Declarations and Bindings
4.1 Overview of Types and Classes
4.2 User-Defined Datatypes
4.3 Type Classes and Overloading
4.4 Nested Declarations
4.5 Static Semantics of Function and Pattern Bindings
4.6 Kind Inference
5 Modules
5.1 Module Structure
5.2 Export Lists
5.3 Import Declarations
5.4 Importing and Exporting Instance Declarations
5.5 Name Clashes and Closure
5.6 Standard Prelude
5.7 Separate Compilation
5.8 Abstract Datatypes
6 Predefined Types and Classes
6.1 Standard Haskell Types
6.2 Strict Evaluation
6.3 Standard Haskell Classes
6.4 Numbers
7 Basic Input/Output
7.1 Standard I/O Functions
7.2 Sequencing I/O Operations
7.3 Exception Handling in the I/O Monad
8 Foreign Function Interface
8.1 Foreign Languages
8.2 Contexts
8.3 Lexical Structure
8.4 Foreign Declarations
8.5 Specification of External Entities
8.6 Marshalling
8.7 The External C Interface
9 Standard Prelude
9.1 Prelude PreludeList
9.2 Prelude PreludeText
9.3 Prelude PreludeIO
10 Syntax Reference
10.1 Notational Conventions
10.2 Lexical Syntax
10.3 Layout
10.4 Literate comments
10.5 Context-Free Syntax
10.6 Fixity Resolution
11 Specification of Derived Instances
11.1 Derived instances of Eq and Ord
11.2 Derived instances of Enum
11.3 Derived instances of Bounded
11.4 Derived instances of Read and Show
11.5 An Example
12 Compiler Pragmas
12.1 Inlining
12.2 Specialization
12.3 Language extensions
II The Haskell 2010 Libraries
13 Control.Monad
13.1 Functor and monad classes
13.2 Functions
14 Data.Array
14.1 Immutable non-strict arrays
14.2 Array construction
14.3 Accessing arrays
14.4 Incremental array updates
14.5 Derived arrays
14.6 Specification
15 Data.Bits
16 Data.Char
16.1 Characters and strings
16.2 Character classification
16.3 Case conversion
16.4 Single digit characters
16.5 Numeric representations
16.6 String representations
17 Data.Complex
17.1 Rectangular form
17.2 Polar form
17.3 Conjugate
17.4 Specification
18 Data.Int
18.1 Signed integer types
19 Data.Ix
19.1 The Ix class
19.2 Deriving Instances of Ix
20 Data.List
20.1 Basic functions
20.2 List transformations
20.3 Reducing lists (folds)
20.4 Building lists
20.5 Sublists
20.6 Searching lists
20.7 Indexing lists
20.8 Zipping and unzipping lists
20.9 Special lists
20.10 Generalized functions
21 Data.Maybe
21.1 The Maybe type and operations
21.2 Specification
22 Data.Ratio
22.1 Specification
23 Data.Word
23.1 Unsigned integral types
24 Foreign
25 Foreign.C
26 Foreign.C.Error
26.1 Haskell representations of errno values
27 Foreign.C.String
27.1 C strings
27.2 C wide strings
28 Foreign.C.Types
28.1 Representations of C types
29 Foreign.ForeignPtr
29.1 Finalised data pointers
30 Foreign.Marshal
31 Foreign.Marshal.Alloc
31.1 Memory allocation
32 Foreign.Marshal.Array
32.1 Marshalling arrays
33 Foreign.Marshal.Error
34 Foreign.Marshal.Utils
34.1 General marshalling utilities
35 Foreign.Ptr
35.1 Data pointers
35.2 Function pointers
35.3 Integral types with lossless conversion to and from pointers
36 Foreign.StablePtr
36.1 Stable references to Haskell values
37 Foreign.Storable
38 Numeric
38.1 Showing
38.2 Reading
38.3 Miscellaneous
39 System.Environment
40 System.Exit
41 System.IO
41.1 The IO monad
41.2 Files and handles
41.3 Opening and closing files
41.4 Operations on handles
41.5 Text input and output
42 System.IO.Error
42.1 I/O errors
42.2 Types of I/O error
42.3 Throwing and catching I/O errors
Bibliography