Module FlatCurry.curry
Library to support meta-programming in Curry.
This library contains a definition for representing FlatCurry programs in Curry (type "Prog") and an I/O action to read Curry programs and transform them into this representation (function "readFlatCurry").
Author: Michael Hanus
Version: June 2009
Summary of exported functions:
readFlatCurry
:: String -> IO Prog 
I/O action which parses a Curry program and returns the corresponding FlatCurry program. |
readFlatCurryWithParseOptions
:: String -> FrontendParams -> IO Prog
I/O action which reads a FlatCurry program from a file with respect to some parser options. |
flatCurryFileName
:: String -> String
Transforms a name of a Curry program (with or without suffix ".curry" or ".lcurry") into the name of the file containing the corresponding FlatCurry program. |
flatCurryIntName
:: String -> String
Transforms a name of a Curry program (with or without suffix ".curry" or ".lcurry") into the name of the file containing the corresponding FlatCurry program. |
readFlatCurryFile
:: String -> IO Prog
I/O action which reads a FlatCurry program from a file in ".fcy" format. |
readFlatCurryInt
:: String -> IO Prog
I/O action which returns the interface of a Curry program, i.e., a FlatCurry program containing only "Public" entities and function definitions without rules (i.e., external functions). |
writeFCY
:: String -> Prog -> IO ()
Writes a FlatCurry program into a file in ".fcy" format. |
showQNameInModule
:: String -> (String,String) -> String 
Translates a given qualified type name into external name relative to a module. |
Exported datatypes:
QName
The data type for representing 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 synonym: QName = (String,String)
TVarIndex
The data type for representing type variables.
They are represented by (TVar i)
where i
is a type variable index.
Type synonym: TVarIndex = Int
VarIndex
Data type for representing object variables.
Object variables occurring in expressions are represented by (Var i)
where i
is a variable index.
Type synonym: VarIndex = Int
Prog
Data type for representing a Curry module in the intermediate form. A value of this data type has the form
(Prog modname imports typedecls functions opdecls translation_table)
where
modname
is the name of this module,
imports
is the list of modules names that are imported,
typedecls, opdecls, functions, translation of type names
and constructor/function names are explained see below
Constructors:
Prog
:: String -> [String] -> [TypeDecl] -> [FuncDecl] -> [OpDecl] -> Prog
Visibility
Data type to specify the visibility of various entities.
Constructors:
Public
:: Visibility
Private
:: Visibility
TypeDecl
Data type for representing definitions of algebraic data types.
A data type definition 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.
Constructors:
Type
:: (String,String) -> Visibility -> [Int] -> [ConsDecl] -> TypeDecl
TypeSyn
:: (String,String) -> Visibility -> [Int] -> TypeExpr -> TypeDecl
ConsDecl
A constructor declaration consists of the name and arity of the constructor and a list of the argument types of the constructor.
Constructors:
Cons
:: (String,String) -> Int -> Visibility -> [TypeExpr] -> ConsDecl
TypeExpr
Data type for 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
:: Int -> TypeExpr
FuncType
:: TypeExpr -> TypeExpr -> TypeExpr
TCons
:: (String,String) -> [TypeExpr] -> TypeExpr
OpDecl
Data type for operator declarations.
An operator declaration fix p n
in Curry corresponds to the
FlatCurry term (Op n fix p).
Constructors:
Op
:: (String,String) -> Fixity -> Int -> OpDecl
Fixity
Data types for the different choices for the fixity of an operator.
Constructors:
InfixOp
:: Fixity
InfixlOp
:: Fixity
InfixrOp
:: Fixity
FuncDecl
Data type for representing function declarations.
A function declaration in FlatCurry is a term of the form
(Func name k type (Rule [i1,...,ik] e))
and represents the function name
with definition
name :: type name x1...xk = e
where each ij
is the index of the variable xj.
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.
Constructors:
Func
:: (String,String) -> Int -> Visibility -> TypeExpr -> Rule -> FuncDecl
Rule
A rule is either a list of formal parameters together with an expression or an "External" tag.
Constructors:
Rule
:: [Int] -> Expr -> Rule
External
:: String -> Rule
CaseType
Data type for classifying case expressions. Case expressions can be either flexible or rigid in Curry.
Constructors:
Rigid
:: CaseType
Flex
:: CaseType
CombType
Data type for classifying combinations (i.e., a function/constructor applied to some arguments).
Constructors:
FuncCall
:: CombType
FuncCall
: a call to a function where all arguments are provided
ConsCall
:: CombType
ConsCall
: a call with a constructor at the top, all arguments are provided
FuncPartCall
:: Int -> CombType
FuncPartCall
: a partial call to a function (i.e., not all arguments
are provided) where the parameter is the number of
missing arguments
ConsPartCall
:: Int -> CombType
ConsPartCall
: a partial call to a constructor (i.e., not all arguments
are provided) where the parameter is the number of
missing arguments
Expr
Data type for representing expressions.
Remarks:
if-then-else expressions are represented as function calls:
(if e1 then e2 else e3)
is represented as
(Comb FuncCall ("Prelude","if_then_else") [e1,e2,e3])
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]))
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") []]))
Constructors:
Var
:: Int -> Expr
Var
: variable (represented by unique index)
Lit
:: Literal -> Expr
Lit
: literal (Int/Float/Char constant)
Comb
:: CombType -> (String,String) -> [Expr] -> Expr
Comb
: application (f e1 ... en)
of function/constructor f
with n<=arity(f)
Let
:: [(Int,Expr)] -> Expr -> Expr
Free
:: [Int] -> Expr -> Expr
Free
: introduction of free local variables
Or
:: Expr -> Expr -> Expr
Or
: disjunction of two expressions (used to translate rules
with overlapping left-hand sides)
Case
:: CaseType -> Expr -> [BranchExpr] -> Expr
Case
: case distinction (rigid or flex)
Typed
:: Expr -> TypeExpr -> Expr
BranchExpr
Data type for representing 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 -> BranchExpr
Pattern
Data type for representing patterns in case expressions.
Constructors:
Pattern
:: (String,String) -> [Int] -> Pattern
LPattern
:: Literal -> Pattern
Literal
Data type for representing literals occurring in an expression or case branch. It is either an integer, a float, or a character constant.
Constructors:
Intc
:: Int -> Literal
Floatc
:: Float -> Literal
Charc
:: Char -> Literal
Exported functions:
|
I/O action which parses a Curry program and returns the corresponding FlatCurry program. Thus, the argument is the file name without suffix ".curry" (or ".lcurry") and the result is a FlatCurry term representing this program. |
|
I/O action which reads a FlatCurry program from a file
with respect to some parser options.
This I/O action is used by the standard action
Example call:
|
|
Transforms a name of a Curry program (with or without suffix ".curry" or ".lcurry") into the name of the file containing the corresponding FlatCurry program. |
|
Transforms a name of a Curry program (with or without suffix ".curry" or ".lcurry") into the name of the file containing the corresponding FlatCurry program. |
|
I/O action which reads a FlatCurry program from a file in ".fcy" format.
In contrast to |
|
I/O action which returns the interface of a Curry program, i.e., a FlatCurry program containing only "Public" entities and function definitions without rules (i.e., external functions). The argument is the file name without suffix ".curry" (or ".lcurry") and the result is a FlatCurry term representing the interface of this program. |
|
Writes a FlatCurry program into a file in ".fcy" format. The first argument must be the name of the target file (with suffix ".fcy"). |
|
Translates a given qualified type name into external name relative to a module. Thus, names not defined in this module (except for names defined in the prelude) are prefixed with their module name. |