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