curry-frontend-2.0.0: Compile the functional logic language Curry to several intermediate formats
Copyright(c) Michael Hanus 2003
Martin Engelke 2004
Bernd Brassel 2005
LicenseBSD-3-clause
Maintainerbjp@informatik.uni-kiel.de
Stabilityexperimental
Portabilityportable
Safe HaskellSafe
LanguageHaskell2010

Curry.FlatCurry.Type

Description

This module contains a definition for representing FlatCurry programs in Haskell in type Prog.

Synopsis

Representation of qualified names and (type) variables

type QName = (String, String) Source #

Qualified names.

In FlatCurry all names are qualified to avoid name clashes. The first component is the module name and the second component the unqualified name as it occurs in the source program.

type VarIndex = Int Source #

Representation of variables.

type TVarIndex = Int Source #

Type variables are represented by (TVar i) where i is a type variable index.

type TVarWithKind = (TVarIndex, Kind) Source #

Kinded type variables are represented by a tuple of type variable index and kind.

Data types for FlatCurry

data Visibility Source #

Visibility of various entities.

Constructors

Public

public (exported) entity

Private

private entity

data Prog Source #

A FlatCurry module.

A value of this data type has the form

Prog modname imports typedecls functions opdecls

where

modname
Name of this module
imports
List of modules names that are imported
typedecls
Type declarations
funcdecls
Function declarations
opdecls
Operator declarations

Constructors

Prog String [String] [TypeDecl] [FuncDecl] [OpDecl] 

Instances

Instances details
Eq Prog Source # 
Instance details

Defined in Curry.FlatCurry.Type

Methods

(==) :: Prog -> Prog -> Bool Source #

(/=) :: Prog -> Prog -> Bool Source #

Read Prog Source # 
Instance details

Defined in Curry.FlatCurry.Type

Show Prog Source # 
Instance details

Defined in Curry.FlatCurry.Type

Binary Prog Source # 
Instance details

Defined in Curry.FlatCurry.Type

Pretty Prog Source # 
Instance details

Defined in Curry.FlatCurry.Pretty

data TypeDecl Source #

Declaration of algebraic data type or type synonym.

A data type declaration of the form

data t x1...xn = ...| c t1....tkc |...

is represented by the FlatCurry term

Type t [i1,...,in] [...(Cons c kc [t1,...,tkc])...]

where each ij is the index of the type variable xj

Note: The type variable indices are unique inside each type declaration and are usually numbered from 0.

Thus, a data type declaration consists of the name of the data type, a list of type parameters and a list of constructor declarations.

data TypeExpr Source #

Type expressions.

A type expression is either a type variable, a function type, or a type constructor application.

Note: the names of the predefined type constructors are Int, Float, Bool, Char, IO, Success, () (unit type), (,...,) (tuple types), [] (list type)

Constructors

TVar TVarIndex

type variable

FuncType TypeExpr TypeExpr

function type t1 -> t2

TCons QName [TypeExpr]

type constructor application

ForallType [TVarWithKind] TypeExpr

forall type

data Kind Source #

Kinds.

A kind is either * or k_1 -> k_2 where k_1 and k_2 are kinds.

Constructors

KStar

star kind

KArrow Kind Kind

arrow kind

Instances

Instances details
Eq Kind Source # 
Instance details

Defined in Curry.FlatCurry.Type

Methods

(==) :: Kind -> Kind -> Bool Source #

(/=) :: Kind -> Kind -> Bool Source #

Ord Kind Source # 
Instance details

Defined in Curry.FlatCurry.Type

Read Kind Source # 
Instance details

Defined in Curry.FlatCurry.Type

Show Kind Source # 
Instance details

Defined in Curry.FlatCurry.Type

Binary Kind Source # 
Instance details

Defined in Curry.FlatCurry.Type

data ConsDecl Source #

A constructor declaration consists of the name and arity of the constructor and a list of the argument types of the constructor.

Constructors

Cons QName Int Visibility [TypeExpr] 

data NewConsDecl Source #

A constructor declaration for a newtype consists of the name of the constructor and the argument type of the constructor.

data OpDecl Source #

Operator declarations.

An operator declaration fix p n in Curry corresponds to the FlatCurry term (Op n fix p).

Note: the constructor definition of Op differs from the original PAKCS definition using Haskell type Integer instead of Int for representing the precedence.

Constructors

Op QName Fixity Integer 

Instances

Instances details
Eq OpDecl Source # 
Instance details

Defined in Curry.FlatCurry.Type

Read OpDecl Source # 
Instance details

Defined in Curry.FlatCurry.Type

Show OpDecl Source # 
Instance details

Defined in Curry.FlatCurry.Type

Binary OpDecl Source # 
Instance details

Defined in Curry.FlatCurry.Type

Pretty OpDecl Source # 
Instance details

Defined in Curry.FlatCurry.Pretty

data Fixity Source #

Fixity of an operator.

Constructors

InfixOp

non-associative infix operator

InfixlOp

left-associative infix operator

InfixrOp

right-associative infix operator

Instances

Instances details
Eq Fixity Source # 
Instance details

Defined in Curry.FlatCurry.Type

Read Fixity Source # 
Instance details

Defined in Curry.FlatCurry.Type

Show Fixity Source # 
Instance details

Defined in Curry.FlatCurry.Type

Binary Fixity Source # 
Instance details

Defined in Curry.FlatCurry.Type

Pretty Fixity Source # 
Instance details

Defined in Curry.FlatCurry.Pretty

data FuncDecl Source #

Data type for representing function declarations.

A function declaration in FlatCurry is a term of the form

(Func name arity type (Rule [i_1,...,i_arity] e))

and represents the function "name" with definition

name :: type
name x_1...x_arity = e

where each i_j is the index of the variable x_j

Note: The variable indices are unique inside each function declaration and are usually numbered from 0.

External functions are represented as

Func name arity type (External s)

where s is the external name associated to this function.

Thus, a function declaration consists of the name, arity, type, and rule.

data Rule Source #

A rule is either a list of formal parameters together with an expression or an External tag.

Constructors

Rule [VarIndex] Expr 
External String 

Instances

Instances details
Eq Rule Source # 
Instance details

Defined in Curry.FlatCurry.Type

Methods

(==) :: Rule -> Rule -> Bool Source #

(/=) :: Rule -> Rule -> Bool Source #

Read Rule Source # 
Instance details

Defined in Curry.FlatCurry.Type

Show Rule Source # 
Instance details

Defined in Curry.FlatCurry.Type

Binary Rule Source # 
Instance details

Defined in Curry.FlatCurry.Type

Pretty Rule Source # 
Instance details

Defined in Curry.FlatCurry.Pretty

data Expr Source #

Data type for representing expressions.

Remarks:

  1. if-then-else expressions are represented as function calls:
(if e1 then e2 else e3)

is represented as

(Comb FuncCall (Prelude,"ifThenElse") [e1,e2,e3])
  1. Higher order applications are represented as calls to the (external) function apply. For instance, the rule
app f x = f x

is represented as

(Rule  [0,1] (Comb FuncCall (Prelude,"apply") [Var 0, Var 1]))
  1. A conditional rule is represented as a call to an external function cond where the first argument is the condition (a constraint).

For instance, the rule

equal2 x | x=:=2 = success

is represented as

  (Rule [0]
      (Comb FuncCall (Prelude,"cond")
            [Comb FuncCall (Prelude,"=:=") [Var 0, Lit (Intc 2)],
            Comb FuncCall (Prelude,"success") []]))
  
  1. Functions with evaluation annotation choice are represented by a rule whose right-hand side is enclosed in a call to the external function Prelude.commit. Furthermore, all rules of the original definition must be represented by conditional expressions (i.e., (cond [c,e])) after pattern matching.

Example:

  m eval choice
  m [] y = y
  m x [] = x
  

is translated into (note that the conditional branches can be also wrapped with Free declarations in general):

  Rule [0,1]
    (Comb FuncCall (Prelude,"commit")
      [Or (Case Rigid (Var 0)
            [(Pattern (Prelude,"[]") []
                (Comb FuncCall (Prelude,"cond")
                      [Comb FuncCall (Prelude,"success") [],
                        Var 1]))] )
          (Case Rigid (Var 1)
            [(Pattern (Prelude,"[]") []
                (Comb FuncCall (Prelude,"cond")
                      [Comb FuncCall (Prelude,"success") [],
                        Var 0]))] )])
  

Operational meaning of (Prelude.commit e): evaluate e with local search spaces and commit to the first (Comb FuncCall (Prelude,"cond") [c,ge]) in e whose constraint c is satisfied

Constructors

Var VarIndex

Variable, represented by unique index

Lit Literal

Literal (IntegerFloatChar constant)

Comb CombType QName [Expr]

Application (f e1 ... en) of function/constructor f with n <= arity f

Free [VarIndex] Expr

Introduction of free local variables for an expression

Let [(VarIndex, Expr)] Expr

Local let-declarations

Or Expr Expr

Disjunction of two expressions (resulting from overlapping left-hand sides)

Case CaseType Expr [BranchExpr]

case expression

Typed Expr TypeExpr

typed expression

Instances

Instances details
Eq Expr Source # 
Instance details

Defined in Curry.FlatCurry.Type

Methods

(==) :: Expr -> Expr -> Bool Source #

(/=) :: Expr -> Expr -> Bool Source #

Read Expr Source # 
Instance details

Defined in Curry.FlatCurry.Type

Show Expr Source # 
Instance details

Defined in Curry.FlatCurry.Type

Binary Expr Source # 
Instance details

Defined in Curry.FlatCurry.Type

Pretty Expr Source # 
Instance details

Defined in Curry.FlatCurry.Pretty

data Literal Source #

Data type for representing literals.

A literal is either an integer, a float, or a character constant.

Note: The constructor definition of Intc differs from the original PAKCS definition. It uses Haskell type Integer instead of Int to provide an unlimited range of integer numbers. Furthermore, float values are represented with Haskell type Double instead of Float.

data CombType Source #

Data type for classifying combinations (i.e., a function/constructor applied to some arguments).

Constructors

FuncCall

a call to a function where all arguments are provided

ConsCall

a call with a constructor at the top, all arguments are provided

FuncPartCall Int

a partial call to a function (i.e., not all arguments are provided) where the parameter is the number of missing arguments

ConsPartCall Int

a partial call to a constructor along with number of missing arguments

data CaseType Source #

Classification of case expressions, either flexible or rigid.

Constructors

Rigid 
Flex 

data BranchExpr Source #

Branches in a case expression.

Branches (m.c x1...xn) -> e in case expressions are represented as

(Branch (Pattern (m,c) [i1,...,in]) e)

where each ij is the index of the pattern variable xj, or as

(Branch (LPattern (Intc i)) e)

for integers as branch patterns (similarly for other literals like float or character constants).

Constructors

Branch Pattern Expr 

data Pattern Source #

Patterns in case expressions.