haskell-src-1.0.1.5: Support for manipulating Haskell source code

Portabilityportable
Stabilityexperimental
Maintainerlibraries@haskell.org
Safe HaskellNone

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.

Instances

Data HsModule 
Show HsModule 
Typeable HsModule 
Pretty HsModule 

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.

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.

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.

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

Eq HsAssoc 
Data HsAssoc 
Show HsAssoc 
Typeable HsAssoc 
Pretty HsAssoc 

Declarations

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.

Instances

Eq HsMatch 
Data HsMatch 
Show HsMatch 
Typeable HsMatch 
Pretty HsMatch 

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

Eq HsRhs 
Data HsRhs 
Show HsRhs 
Typeable HsRhs 
Pretty HsRhs 

data HsGuardedRhs Source

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

data HsSafety Source

Safety level for invoking a foreign entity

Constructors

HsSafe

call may generate callbacks

HsUnsafe

call will not generate callbacks

Instances

Eq HsSafety 
Data HsSafety 
Ord HsSafety 
Show HsSafety 
Typeable HsSafety 
Pretty HsSafety 

Class Assertions and Contexts

data HsQualType Source

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

Instances

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

Eq HsType 
Data HsType 
Show HsType 
Typeable HsType 
Pretty HsType 

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

Eq HsExp 
Data HsExp 
Show HsExp 
Typeable HsExp 
Pretty HsExp 

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

Eq HsStmt 
Data HsStmt 
Show HsStmt 
Typeable HsStmt 
Pretty HsStmt 

data HsFieldUpdate Source

An fbind in a labeled record construction or update expression.

data HsAlt Source

An alt in a case expression.

Instances

Eq HsAlt 
Data HsAlt 
Show HsAlt 
Typeable HsAlt 
Pretty HsAlt 

data HsGuardedAlt Source

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

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

Eq HsPat 
Data HsPat 
Show HsPat 
Typeable HsPat 
Pretty HsPat 

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

Eq Module 
Data Module 
Ord Module 
Show Module 
Typeable Module 
Pretty Module 

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

Eq HsQName 
Data HsQName 
Ord HsQName 
Show HsQName 
Typeable HsQName 
Pretty HsQName 

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

Eq HsName 
Data HsName 
Ord HsName 
Show HsName 
Typeable HsName 
Pretty HsName 

data HsQOp Source

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

Constructors

HsQVarOp HsQName

variable operator (qvarop)

HsQConOp HsQName

constructor operator (qconop)

Instances

Eq HsQOp 
Data HsQOp 
Ord HsQOp 
Show HsQOp 
Typeable HsQOp 
Pretty HsQOp 

data HsOp Source

Operators, appearing in infix declarations.

Constructors

HsVarOp HsName

variable operator (varop)

HsConOp HsName

constructor operator (conop)

Instances

Eq HsOp 
Data HsOp 
Ord HsOp 
Show HsOp 
Typeable HsOp 
Pretty HsOp 

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

Eq HsCName 
Data HsCName 
Ord HsCName 
Show HsCName 
Typeable HsCName 
Pretty HsCName 

Builtin names

Modules

Main function of a program

Constructors

Type constructors

Source coordinates

data SrcLoc Source

A position in the source.

Constructors

SrcLoc 

Fields

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

Instances

Eq SrcLoc 
Data SrcLoc 
Ord SrcLoc 
Show SrcLoc 
Typeable SrcLoc