IL.Type

The module IL defines the intermediate language which will be compiled into abstract machine code. The intermediate language removes a lot of syntactic sugar from the Curry source language. Top-level declarations are restricted to data type and function definitions. A newtype definition serves mainly as a hint to the backend that it must provide an auxiliary function for partial applications of the constructor (Newtype constructors must not occur in patterns and may be used in expressions only as partial applications.).

Type declarations use a de-Bruijn indexing scheme (starting at 0) for type variables. In the type of a function, all type variables are numbered in the order of their occurence from left to right, i.e., a type '(Int -> b) -> (a,b) -> c -> (a,c)' is translated into the type (using integer numbers to denote the type variables) '(Int -> 0) -> (1,0) -> 2 -> (1,2)'.

Pattern matching in an equation is handled via flexible and rigid Case expressions. Overlapping rules are translated with the help of Or expressions. The intermediate language has three kinds of binding expressions, Exist expressions introduce a new logical variable, Let expression support a single non-recursive variable binding, and Letrec expressions introduce multiple variables with recursive initializer expressions. The intermediate language explicitly distinguishes (local) variables and (global) functions in expressions.

Note: this modified version uses haskell type Integer instead of Int for representing integer values. This provides an unlimited range of integer constants in Curry programs.

Data types

data Module

Constructors

Module ModuleIdent [ModuleIdent] [Decl]

Instances

Eq Module

Methods

(==) :: Module -> Module -> Bool

(/=) :: Module -> Module -> Bool

Show Module

Methods

showsPrec :: Int -> Module -> ShowS

show :: Module -> String

showList :: [Module] -> ShowS

data Decl

Constructors

DataDecl QualIdent Int [ConstrDecl]

ExternalDataDecl QualIdent Int

FunctionDecl QualIdent [(Type, Ident)] Type Expression

ExternalDecl QualIdent Type

Instances

Eq Decl

Methods

(==) :: Decl -> Decl -> Bool

(/=) :: Decl -> Decl -> Bool

Show Decl

Methods

showsPrec :: Int -> Decl -> ShowS

show :: Decl -> String

showList :: [Decl] -> ShowS

data ConstrDecl

Constructors

ConstrDecl QualIdent [Type]

Instances

Eq ConstrDecl

Methods

(==) :: ConstrDecl -> ConstrDecl -> Bool

(/=) :: ConstrDecl -> ConstrDecl -> Bool

Show ConstrDecl

Methods

showsPrec :: Int -> ConstrDecl -> ShowS

show :: ConstrDecl -> String

showList :: [ConstrDecl] -> ShowS

data Type

Constructors

TypeConstructor QualIdent [Type]

TypeVariable Int

TypeArrow Type Type

TypeForall [Int] Type

Instances

Eq Type

Methods

(==) :: Type -> Type -> Bool

(/=) :: Type -> Type -> Bool

Show Type

Methods

showsPrec :: Int -> Type -> ShowS

show :: Type -> String

showList :: [Type] -> ShowS

data Literal

Constructors

Char Char

Int Integer

Float Double

Instances

Eq Literal

Methods

(==) :: Literal -> Literal -> Bool

(/=) :: Literal -> Literal -> Bool

Show Literal

Methods

showsPrec :: Int -> Literal -> ShowS

show :: Literal -> String

showList :: [Literal] -> ShowS

data ConstrTerm

Constructors

LiteralPattern Type Literal

literal patterns

ConstructorPattern Type QualIdent [(Type, Ident)]

constructors

VariablePattern Type Ident

default

Instances

Eq ConstrTerm

Methods

(==) :: ConstrTerm -> ConstrTerm -> Bool

(/=) :: ConstrTerm -> ConstrTerm -> Bool

Show ConstrTerm

Methods

showsPrec :: Int -> ConstrTerm -> ShowS

show :: ConstrTerm -> String

showList :: [ConstrTerm] -> ShowS

Typeable ConstrTerm

Methods

typeOf :: ConstrTerm -> Type

data Expression

Constructors

Literal Type Literal

literal constants

Variable Type Ident

variables

Function Type QualIdent Int

functions

Constructor Type QualIdent Int

constructors

Apply Expression Expression

applications

Case Eval Expression [Alt]

case expressions

Or Expression Expression

non-deterministic or

Exist Ident Expression

exist binding (introduction of a free variable)

Let Binding Expression

let binding

Letrec [Binding] Expression

letrec binding

Typed Expression Type

typed expression

Instances

Eq Expression

Methods

(==) :: Expression -> Expression -> Bool

(/=) :: Expression -> Expression -> Bool

Show Expression

Methods

showsPrec :: Int -> Expression -> ShowS

show :: Expression -> String

showList :: [Expression] -> ShowS

Expr Expression

Methods

fv :: Expression -> [Ident]

Typeable Expression

Methods

typeOf :: Expression -> Type

data Eval

Constructors

Rigid

Flex

Instances

Eq Eval

Methods

(==) :: Eval -> Eval -> Bool

(/=) :: Eval -> Eval -> Bool

Show Eval

Methods

showsPrec :: Int -> Eval -> ShowS

show :: Eval -> String

showList :: [Eval] -> ShowS

data Alt

Constructors

Alt ConstrTerm Expression

Instances

Eq Alt

Methods

(==) :: Alt -> Alt -> Bool

(/=) :: Alt -> Alt -> Bool

Show Alt

Methods

showsPrec :: Int -> Alt -> ShowS

show :: Alt -> String

showList :: [Alt] -> ShowS

Expr Alt

Methods

fv :: Alt -> [Ident]

Typeable Alt

Methods

typeOf :: Alt -> Type

data Binding

Constructors

Binding Ident Expression

Instances

Eq Binding

Methods

(==) :: Binding -> Binding -> Bool

(/=) :: Binding -> Binding -> Bool

Show Binding

Methods

showsPrec :: Int -> Binding -> ShowS

show :: Binding -> String

showList :: [Binding] -> ShowS