haskell-src-1.0.2.0: Support for manipulating Haskell source code

Copyright(c) The GHC Team, 1997-2000
LicenseBSD-style (see the file libraries/base/LICENSE)
Maintainerlibraries@haskell.org
Stabilityexperimental
Portabilityportable
Safe HaskellNone
LanguageHaskell98

Language.Haskell.Syntax

Contents

Description

A suite of datatypes describing the abstract syntax of Haskell 98 http://www.haskell.org/onlinereport/ plus a few extensions:

  • multi-parameter type classes
  • parameters of type class assertions are unrestricted

This module has been changed so that show is a real show. For GHC, we also derive Typeable and Data for all types.

Synopsis

Modules

data HsModule Source

A Haskell source module.

Constructors

HsModule SrcLoc Module (Maybe [HsExportSpec]) [HsImportDecl] [HsDecl] 

Instances

data HsExportSpec Source

Export specification.

Constructors

HsEVar HsQName

variable

HsEAbs HsQName

T: a class or datatype exported abstractly, or a type synonym.

HsEThingAll HsQName

T(..): a class exported with all of its methods, or a datatype exported with all of its constructors.

HsEThingWith HsQName [HsCName]

T(C_1,...,C_n): a class exported with some of its methods, or a datatype exported with some of its constructors.

HsEModuleContents Module

module M: re-export a module.

Instances

data HsImportDecl Source

Import declaration.

Constructors

HsImportDecl 

Fields

importLoc :: SrcLoc

position of the import keyword.

importModule :: Module

name of the module imported.

importQualified :: Bool

imported qualified?

importAs :: Maybe Module

optional alias name in an as clause.

importSpecs :: Maybe (Bool, [HsImportSpec])

optional list of import specifications. The Bool is True if the names are excluded by hiding.

Instances

data HsImportSpec Source

Import specification.

Constructors

HsIVar HsName

variable

HsIAbs HsName

T: the name of a class, datatype or type synonym.

HsIThingAll HsName

T(..): a class imported with all of its methods, or a datatype imported with all of its constructors.

HsIThingWith HsName [HsCName]

T(C_1,...,C_n): a class imported with some of its methods, or a datatype imported with some of its constructors.

Instances

data HsAssoc Source

Associativity of an operator.

Constructors

HsAssocNone

non-associative operator (declared with infix)

HsAssocLeft

left-associative operator (declared with infixl).

HsAssocRight

right-associative operator (declared with infixr)

Instances

Declarations

data HsDecl Source

Constructors

HsTypeDecl SrcLoc HsName [HsName] HsType 
HsDataDecl SrcLoc HsContext HsName [HsName] [HsConDecl] [HsQName] 
HsInfixDecl SrcLoc HsAssoc Int [HsOp] 
HsNewTypeDecl SrcLoc HsContext HsName [HsName] HsConDecl [HsQName] 
HsClassDecl SrcLoc HsContext HsName [HsName] [HsDecl] 
HsInstDecl SrcLoc HsContext HsQName [HsType] [HsDecl] 
HsDefaultDecl SrcLoc [HsType] 
HsTypeSig SrcLoc [HsName] HsQualType 
HsFunBind [HsMatch] 
HsPatBind SrcLoc HsPat HsRhs [HsDecl] 
HsForeignImport SrcLoc String HsSafety String HsName HsType 
HsForeignExport SrcLoc String String HsName HsType 

Instances

data HsConDecl Source

Declaration of a data constructor.

Constructors

HsConDecl SrcLoc HsName [HsBangType]

ordinary data constructor

HsRecDecl SrcLoc HsName [([HsName], HsBangType)]

record constructor

Instances

data HsBangType Source

The type of a constructor argument or field, optionally including a strictness annotation.

Constructors

HsBangedTy HsType

strict component, marked with "!"

HsUnBangedTy HsType

non-strict component

Instances

data HsMatch Source

Clauses of a function binding.

Constructors

HsMatch SrcLoc HsName [HsPat] HsRhs [HsDecl] 

Instances

data HsRhs Source

The right hand side of a function or pattern binding.

Constructors

HsUnGuardedRhs HsExp

unguarded right hand side (exp)

HsGuardedRhss [HsGuardedRhs]

guarded right hand side (gdrhs)

Instances

data HsGuardedRhs Source

A guarded right hand side | exp = exp. The first expression will be Boolean-valued.

Constructors

HsGuardedRhs SrcLoc HsExp HsExp 

Instances

data HsSafety Source

Safety level for invoking a foreign entity

Constructors

HsSafe

call may generate callbacks

HsUnsafe

call will not generate callbacks

Instances

Class Assertions and Contexts

data HsQualType Source

A type qualified with a context. An unqualified type has an empty context.

Constructors

HsQualType HsContext HsType 

Instances

type HsContext = [HsAsst] Source

type HsAsst = (HsQName, [HsType]) Source

Class assertions. In Haskell 98, the argument would be a tyvar, but this definition allows multiple parameters, and allows them to be types.

Types

data HsType Source

Haskell types and type constructors.

Constructors

HsTyFun HsType HsType

function type

HsTyTuple [HsType]

tuple type

HsTyApp HsType HsType

application of a type constructor

HsTyVar HsName

type variable

HsTyCon HsQName

named type or type constructor

Instances

Expressions

data HsExp Source

Haskell expressions.

Notes:

  • Because it is difficult for parsers to distinguish patterns from expressions, they typically parse them in the same way and then check that they have the appropriate form. Hence the expression type includes some forms that are found only in patterns. After these checks, these constructors should not be used.
  • The parser does not take precedence and associativity into account, so it will leave HsInfixApps associated to the left.
  • The Pretty instance for HsExp does not add parentheses in printing.

Constructors

HsVar HsQName

variable

HsCon HsQName

data constructor

HsLit HsLiteral

literal constant

HsInfixApp HsExp HsQOp HsExp

infix application

HsApp HsExp HsExp

ordinary application

HsNegApp HsExp

negation expression - exp

HsLambda SrcLoc [HsPat] HsExp

lambda expression

HsLet [HsDecl] HsExp

local declarations with let

HsIf HsExp HsExp HsExp

if exp then exp else exp

HsCase HsExp [HsAlt]

case exp of alts

HsDo [HsStmt]

do-expression: the last statement in the list should be an expression.

HsTuple [HsExp]

tuple expression

HsList [HsExp]

list expression

HsParen HsExp

parenthesized expression

HsLeftSection HsExp HsQOp

left section (exp qop)

HsRightSection HsQOp HsExp

right section (qop exp)

HsRecConstr HsQName [HsFieldUpdate]

record construction expression

HsRecUpdate HsExp [HsFieldUpdate]

record update expression

HsEnumFrom HsExp

unbounded arithmetic sequence, incrementing by 1

HsEnumFromTo HsExp HsExp

bounded arithmetic sequence, incrementing by 1

HsEnumFromThen HsExp HsExp

unbounded arithmetic sequence, with first two elements given

HsEnumFromThenTo HsExp HsExp HsExp

bounded arithmetic sequence, with first two elements given

HsListComp HsExp [HsStmt]

list comprehension

HsExpTypeSig SrcLoc HsExp HsQualType

expression type signature

HsAsPat HsName HsExp

patterns only

HsWildCard

patterns only

HsIrrPat HsExp

patterns only

Instances

data HsStmt Source

This type represents both stmt in a do-expression, and qual in a list comprehension.

Constructors

HsGenerator SrcLoc HsPat HsExp

a generator pat <- exp

HsQualifier HsExp

an exp by itself: in a do-expression, an action whose result is discarded; in a list comprehension, a guard expression

HsLetStmt [HsDecl]

local bindings

Instances

data HsFieldUpdate Source

An fbind in a labeled record construction or update expression.

Constructors

HsFieldUpdate HsQName HsExp 

Instances

data HsAlt Source

An alt in a case expression.

Constructors

HsAlt SrcLoc HsPat HsGuardedAlts [HsDecl] 

Instances

data HsGuardedAlts Source

Constructors

HsUnGuardedAlt HsExp

-> exp

HsGuardedAlts [HsGuardedAlt]

gdpat

Instances

data HsGuardedAlt Source

A guarded alternative | exp -> exp. The first expression will be Boolean-valued.

Constructors

HsGuardedAlt SrcLoc HsExp HsExp 

Instances

Patterns

data HsPat Source

A pattern, to be matched against a value.

Constructors

HsPVar HsName

variable

HsPLit HsLiteral

literal constant

HsPNeg HsPat

negated pattern

HsPInfixApp HsPat HsQName HsPat

pattern with infix data constructor

HsPApp HsQName [HsPat]

data constructor and argument patterns

HsPTuple [HsPat]

tuple pattern

HsPList [HsPat]

list pattern

HsPParen HsPat

parenthesized pattern

HsPRec HsQName [HsPatField]

labelled pattern

HsPAsPat HsName HsPat

@-pattern

HsPWildCard

wildcard pattern (_)

HsPIrrPat HsPat

irrefutable pattern (~)

Instances

data HsPatField Source

An fpat in a labeled record pattern.

Constructors

HsPFieldPat HsQName HsPat 

Instances

Literals

data HsLiteral Source

literal. Values of this type hold the abstract value of the literal, not the precise string representation used. For example, 10, 0o12 and 0xa have the same representation.

Constructors

HsChar Char

character literal

HsString String

string literal

HsInt Integer

integer literal

HsFrac Rational

floating point literal

HsCharPrim Char

GHC unboxed character literal

HsStringPrim String

GHC unboxed string literal

HsIntPrim Integer

GHC unboxed integer literal

HsFloatPrim Rational

GHC unboxed float literal

HsDoublePrim Rational

GHC unboxed double literal

Instances

Variables, Constructors and Operators

newtype Module Source

The name of a Haskell module.

Constructors

Module String 

Instances

data HsQName Source

This type is used to represent qualified variables, and also qualified constructors.

Constructors

Qual Module HsName

name qualified with a module name

UnQual HsName

unqualified name

Special HsSpecialCon

built-in constructor with special syntax

Instances

data HsName Source

This type is used to represent variables, and also constructors.

Constructors

HsIdent String

varid or conid

HsSymbol String

varsym or consym

Instances

data HsQOp Source

Possibly qualified infix operators (qop), appearing in expressions.

Constructors

HsQVarOp HsQName

variable operator (qvarop)

HsQConOp HsQName

constructor operator (qconop)

Instances

data HsOp Source

Operators, appearing in infix declarations.

Constructors

HsVarOp HsName

variable operator (varop)

HsConOp HsName

constructor operator (conop)

Instances

data HsSpecialCon Source

Constructors with special syntax. These names are never qualified, and always refer to builtin type or data constructors.

Constructors

HsUnitCon

unit type and data constructor ()

HsListCon

list type constructor []

HsFunCon

function type constructor ->

HsTupleCon Int

n-ary tuple type and data constructors (,) etc

HsCons

list data constructor (:)

Instances

data HsCName Source

A name (cname) of a component of a class or data type in an import or export specification.

Constructors

HsVarName HsName

name of a method or field

HsConName HsName

name of a data constructor

Instances

Builtin names

Modules

prelude_mod :: Module Source

main_mod :: Module Source

Main function of a program

main_name :: HsName Source

Constructors

unit_con_name :: HsQName Source

tuple_con_name :: Int -> HsQName Source

list_cons_name :: HsQName Source

unit_con :: HsExp Source

tuple_con :: Int -> HsExp Source

Type constructors

unit_tycon_name :: HsQName Source

fun_tycon_name :: HsQName Source

list_tycon_name :: HsQName Source

tuple_tycon_name :: Int -> HsQName Source

unit_tycon :: HsType Source

fun_tycon :: HsType Source

list_tycon :: HsType Source

tuple_tycon :: Int -> HsType Source

Source coordinates

data SrcLoc Source

A position in the source.

Constructors

SrcLoc 

Fields

srcFilename :: String
 
srcLine :: Int
 
srcColumn :: Int
 

Instances