{- |

Module : $Header$

Description : abstract syntax for HasCASL

Copyright : (c) Christian Maeder and Uni Bremen 2003-2005

License : similar to LGPL, see HetCATS/LICENSE.txt or LIZENZ.txt

Maintainer : Christian.Maeder@dfki.de

Stability : experimental

Portability : portable

abstract syntax for HasCASL,

more liberal than Concrete-Syntax.txt,

annotations are almost as for CASL

-}

module HasCASL.As where

import Common.Id

import Common.Keywords

import Common.AS_Annotation

import qualified Data.Set as Set

-- * abstract syntax entities with small utility functions

-- | annotated basic items

data BasicSpec = BasicSpec [Annoted BasicItem] deriving Show

-- | the possible items

data BasicItem =

SigItems SigItems

| ProgItems [Annoted ProgEq] Range

-- pos "program", dots

| ClassItems Instance [Annoted ClassItem] Range

-- pos "class", ";"s

| GenVarItems [GenVarDecl] Range

-- pos "var", ";"s

| FreeDatatype [Annoted DatatypeDecl] Range

-- pos "free", "type", ";"s

| GenItems [Annoted SigItems] Range

-- pos "generated" "{", ";"s, "}"

-- or "generated" "type" ";"s

| AxiomItems [GenVarDecl] [Annoted Term] Range

-- pos "forall" (if GenVarDecl not empty), dots

| Internal [Annoted BasicItem] Range

-- pos "internal" "{", ";"s, "}"

deriving Show

-- | signature items are types or functions

data SigItems =

TypeItems Instance [Annoted TypeItem] Range -- including sort

-- pos "type", ";"s

| OpItems OpBrand [Annoted OpItem] Range

-- pos "op", ";"s

deriving Show

-- | indicator for predicate, operation or function

data OpBrand = Pred | Op | Fun deriving (Eq, Ord)

-- | test if the function was declared as predicate

isPred :: OpBrand -> Bool

isPred b = case b of

Pred -> True

_ -> False

instance Show OpBrand where

show b = case b of

Pred -> predS

Op -> opS

Fun -> functS

-- | indicator in 'ClassItems' and 'TypeItems'

data Instance = Instance | Plain

instance Show Instance where

show i = case i of

Instance -> instanceS

Plain -> ""

-- | a class item

data ClassItem = ClassItem ClassDecl [Annoted BasicItem] Range deriving Show

-- pos "{", ";"s "}"

-- | declaring class identifiers

data ClassDecl = ClassDecl [Id] Kind Range deriving Show

-- pos ","s

-- | co- or contra- variance indicator

data Variance = InVar | CoVar | ContraVar | NonVar deriving (Eq, Ord)

instance Show Variance where

show v = case v of

InVar -> plusS ++ minusS

CoVar -> plusS

ContraVar -> minusS

NonVar -> ""

-- | (higher) kinds

data AnyKind a =

ClassKind a

| FunKind Variance (AnyKind a) (AnyKind a) Range

-- pos "+" or "-"

deriving Show

instance Ord a => Eq (AnyKind a) where

k1 == k2 = compare k1 k2 == EQ

instance Ord a => Ord (AnyKind a) where

compare k1 k2 = case (k1, k2) of

(ClassKind c1, ClassKind c2) -> compare c1 c2

(ClassKind _, _) -> LT

(FunKind v1 k3 k4 _, FunKind v2 k5 k6 _) ->

compare (v1, k3, k4) (v2, k5, k6)

_ -> GT

type Kind = AnyKind Id

type RawKind = AnyKind ()

-- | the possible type items

data TypeItem =

TypeDecl [TypePattern] Kind Range

-- pos ","s

| SubtypeDecl [TypePattern] Type Range

-- pos ","s, "<"

| IsoDecl [TypePattern] Range

-- pos "="s

| SubtypeDefn TypePattern Vars Type (Annoted Term) Range

-- pos "=", "{", ":", dot, "}"

| AliasType TypePattern (Maybe Kind) TypeScheme Range

-- pos ":="

| Datatype DatatypeDecl

deriving Show

-- | a tuple pattern for 'SubtypeDefn'

data Vars = Var Id | VarTuple [Vars] Range deriving (Show, Eq)

-- | the lhs of most type items

data TypePattern =

TypePattern Id [TypeArg] Range

-- pos "("s, ")"s

| TypePatternToken Token

| MixfixTypePattern [TypePattern]

| BracketTypePattern BracketKind [TypePattern] Range

-- pos brackets (no parenthesis)

| TypePatternArg TypeArg Range

-- pos "(", ")"

deriving Show

-- | types based on variable or constructor names and applications

data Type =

TypeName Id RawKind Int

-- Int == 0 means constructor, negative are bound variables

| TypeAppl Type Type

| ExpandedType Type Type -- an alias type with its expansion

-- only the following variants are parsed

| TypeAbs TypeArg Type Range

| KindedType Type (Set.Set Kind) Range

-- pos ":"

| TypeToken Token

| BracketType BracketKind [Type] Range

-- pos "," (between type arguments)

| MixfixType [Type]

deriving Show

-- | change the type within a scheme

mapTypeOfScheme :: (Type -> Type) -> TypeScheme -> TypeScheme

mapTypeOfScheme f (TypeScheme args t ps) = TypeScheme args (f t) ps

{- | a type with bound type variables. The bound variables within the

scheme should have negative numbers in the order given by the type

argument list. The type arguments store proper kinds (including

downsets) whereas the kind within the type names are only raw

kinds. -}

data TypeScheme = TypeScheme [TypeArg] Type Range deriving (Show, Eq, Ord)

-- pos "forall", ";"s, dot (singleton list)

-- pos "\" "("s, ")"s, dot for type aliases

-- | indicator for partial or total functions

data Partiality = Partial | Total deriving (Eq, Ord)

instance Show Partiality where

show p = case p of

Partial -> quMark

Total -> exMark

-- | function declarations or definitions

data OpItem =

OpDecl [PolyId] TypeScheme [OpAttr] Range

-- pos ","s, ":", ","s, "assoc", "comm", "idem", "unit"

| OpDefn PolyId [[VarDecl]] TypeScheme Term Range

-- pos "("s, ";"s, ")"s, ":" and "="

deriving Show

-- | attributes without arguments for binary functions

data BinOpAttr = Assoc | Comm | Idem deriving (Eq, Ord)

instance Show BinOpAttr where

show a = case a of

Assoc -> assocS

Comm -> commS

Idem -> idemS

-- | possible function attributes (including a term as a unit element)

data OpAttr =

BinOpAttr BinOpAttr Range

| UnitOpAttr Term Range deriving Show

instance Eq OpAttr where

o1 == o2 = compare o1 o2 == EQ

instance Ord OpAttr where

compare o1 o2 = case (o1, o2) of

(BinOpAttr b1 _, BinOpAttr b2 _) -> compare b1 b2

(BinOpAttr _ _, _) -> LT

(UnitOpAttr t1 _, UnitOpAttr t2 _) -> compare t1 t2

_ -> GT

-- | a polymorphic data type declaration with a deriving clause

data DatatypeDecl =

DatatypeDecl TypePattern Kind [Annoted Alternative] [Id] Range

-- pos "::=", "|"s, "deriving"

deriving Show

{- | Alternatives are subtypes or a constructor with a list of

(curried) tuples as arguments. Only the components of the first tuple

can be addressed by the places of the mixfix constructor. -}

data Alternative =

Constructor Id [[Component]] Partiality Range

-- pos: "("s, ";"s, ")"s, "?"

| Subtype [Type] Range

-- pos: "type", ","s

deriving Show

{- | A component is a type with on optional (only pre- or postfix)

selector function. -}

data Component =

Selector Id Partiality Type SeparatorKind Range

-- pos ",", ":" or ":?"

| NoSelector Type

deriving (Show, Eq, Ord)

-- | the possible quantifiers

data Quantifier = Universal | Existential | Unique deriving (Eq, Ord, Show)

-- | the possibly type annotations of terms

data TypeQual = OfType | AsType | InType | Inferred deriving (Eq, Ord, Show)

-- | an indicator of (otherwise equivalent) let or where equations

data LetBrand = Let | Where | Program deriving (Show, Eq, Ord)

-- | the possible kinds of brackets (that should match when parsed)

data BracketKind =

Parens | Squares | Braces | NoBrackets deriving (Show, Eq, Ord)

-- | the brackets as strings for printing

getBrackets :: BracketKind -> (String, String)

getBrackets b = case b of

Parens -> ("(", ")")

Squares -> ("[", "]")

Braces -> ("{", "}")

NoBrackets -> ("", "") -- for printing only

data InstKind = UserGiven | Infer deriving (Show, Eq, Ord)

{- | The possible terms and patterns. Formulas are also kept as

terms. Local variables and constants are kept separatetly. The variant

'ResolvedMixTerm' is an intermediate representation for type checking

only. -}

data Term =

QualVar VarDecl

-- pos "(", "var", ":", ")"

| QualOp OpBrand PolyId TypeScheme [Type] InstKind Range

-- pos "(", "op", ":", ")"

| ApplTerm Term Term Range -- analysed

-- pos?

| TupleTerm [Term] Range -- special application

-- pos "(", ","s, ")"

| TypedTerm Term TypeQual Type Range

-- pos ":", "as" or "in"

| AsPattern VarDecl Term Range

-- pos "@"

-- patterns are terms constructed by the first six variants

| QuantifiedTerm Quantifier [GenVarDecl] Term Range

-- pos quantifier, ";"s, dot

-- only "forall" may have a TypeVarDecl

| LambdaTerm [Term] Partiality Term Range

-- pos "\", dot (plus "!")

| CaseTerm Term [ProgEq] Range

-- pos "case", "of", "|"s

| LetTerm LetBrand [ProgEq] Term Range

-- pos "where", ";"s

| ResolvedMixTerm Id [Type] [Term] Range

| TermToken Token

| MixTypeTerm TypeQual Type Range

| MixfixTerm [Term]

| BracketTerm BracketKind [Term] Range

-- pos brackets, ","s

deriving (Show, Eq, Ord)

-- | an equation or a case as pair of a pattern and a term

data ProgEq = ProgEq Term Term Range deriving (Show, Eq, Ord)

-- pos "=" (or "->" following case-of)

-- | an identifier with an optional list of type declarations

data PolyId = PolyId Id [TypeArg] Range deriving (Show, Eq, Ord)

-- pos "[", ",", "]"

{- | an indicator if variables were separated by commas or by separate

declarations -}

data SeparatorKind = Comma | Other deriving Show

-- ignore all separator kinds in comparisons

instance Eq SeparatorKind where

_ == _ = True

-- Ord must be consistent with Eq

instance Ord SeparatorKind where

compare _ _ = EQ

-- | a variable with its type

data VarDecl = VarDecl Id Type SeparatorKind Range deriving (Show, Eq, Ord)

-- pos "," or ":"

-- | the kind of a type variable (or a type argument in schemes)

data VarKind =

VarKind Kind | Downset Type | MissingKind deriving (Show, Eq, Ord)

-- | a (simple) type variable with its kind (or supertype)

data TypeArg =

TypeArg Id Variance VarKind RawKind Int SeparatorKind Range

-- pos "," or ":", "+" or "-"

deriving Show

-- | a value or type variable

data GenVarDecl =

GenVarDecl VarDecl

| GenTypeVarDecl TypeArg

deriving (Show, Eq, Ord)

-- * symbol data types

-- | symbols

data SymbItems =

SymbItems SymbKind [Symb] [Annotation] Range deriving (Show, Eq)

-- pos: kind, commas

-- | mapped symbols

data SymbMapItems =

SymbMapItems SymbKind [SymbOrMap] [Annotation] Range deriving (Show, Eq)

-- pos: kind commas

-- | kind of symbols

data SymbKind =

Implicit

| SK_type

| SK_sort

| SK_fun

| SK_op

| SK_pred

| SK_class

deriving (Show, Eq, Ord)

-- | type annotated symbols

data Symb = Symb Id (Maybe SymbType) Range deriving (Show, Eq)

-- pos: colon (or empty)

-- | type for symbols

data SymbType = SymbType TypeScheme deriving (Show, Eq)

-- | mapped symbol

data SymbOrMap = SymbOrMap Symb (Maybe Symb) Range deriving (Show, Eq)

-- pos: "|->" (or empty)

-- * equality instances ignoring positions

instance Eq Type where

t1 == t2 = compare t1 t2 == EQ

instance Ord Type where

compare ty1 ty2 = case (ty1, ty2) of

(TypeName i1 k1 v1, TypeName i2 k2 v2) ->

if v1 == 0 && v2 == 0 then compare (i1, k1) (i2, k2)

else compare (v1, k1) (v2, k2)

(TypeAppl f1 a1, TypeAppl f2 a2) -> compare (f1, a1) (f2, a2)

(TypeAbs v1 a1 _, TypeAbs v2 a2 _) -> compare (v1, a1) (v2, a2)

(TypeToken t1, TypeToken t2) -> compare t1 t2

(BracketType b1 l1 _, BracketType b2 l2 _) -> compare (b1, l1) (b2, l2)

(KindedType t1 k1 _, KindedType t2 k2 _) -> compare (t1, k1) (t2, k2)

(MixfixType l1, MixfixType l2) -> compare l1 l2

(ExpandedType _ t1, t2) -> compare t1 t2

(t1, ExpandedType _ t2) -> compare t1 t2

(TypeName _ _ _, _) -> LT

(_, TypeName _ _ _) -> GT

(TypeAppl _ _, _) -> LT

(_, TypeAppl _ _) -> GT

(TypeAbs _ _ _, _) -> LT

(_, TypeAbs _ _ _) -> GT

(TypeToken _, _) -> LT

(_, TypeToken _) -> GT

(BracketType _ _ _, _) -> LT

(_, BracketType _ _ _) -> GT

(KindedType _ _ _, _) -> LT

(_, KindedType _ _ _) -> GT

-- used within quantified formulas

instance Eq TypeArg where

t1 == t2 = compare t1 t2 == EQ

instance Ord TypeArg where

compare (TypeArg i1 v1 e1 r1 c1 _ _) (TypeArg i2 v2 e2 r2 c2 _ _) =

if c1 < 0 && c2 < 0 then compare (v1, e1, r1, c1) (v2, e2, r2, c2)

else compare (i1, v1, e1, r1, c1) (i2, v2, e2, r2, c2)

-- * compute better position

instance PosItem Type where

getRange ty = case ty of

TypeName i _ _ -> posOfId i

TypeAppl t1 t2 -> posOf [t1, t2]

TypeAbs _ t ps -> firstPos [t] ps

ExpandedType t1 t2 -> posOf [t1, t2]

TypeToken t -> tokPos t

BracketType _ ts ps -> firstPos ts ps

KindedType t _ ps -> firstPos [t] ps

MixfixType ts -> posOf ts

instance PosItem Term where

getRange trm = case trm of

QualVar v -> getRange v

QualOp _ (PolyId i _ _) _ _ _ qs -> firstPos [i] qs

ResolvedMixTerm i _ _ _ -> posOfId i

ApplTerm t1 t2 ps -> firstPos [t1, t2] ps

TupleTerm ts ps -> firstPos ts ps

TypedTerm t _ _ ps -> firstPos [t] ps

QuantifiedTerm _ _ t ps -> firstPos [t] ps

LambdaTerm _ _ t ps -> firstPos [t] ps

CaseTerm t _ ps -> firstPos [t] ps

LetTerm _ _ t ps -> firstPos [t] ps

TermToken t -> tokPos t

MixTypeTerm _ t ps -> firstPos [t] ps

MixfixTerm ts -> posOf ts

BracketTerm _ ts ps -> firstPos ts ps

AsPattern v _ ps -> firstPos [v] ps

instance PosItem TypePattern where

getRange pat = case pat of

TypePattern t _ ps -> firstPos [t] ps

TypePatternToken t -> tokPos t

MixfixTypePattern ts -> posOf ts

BracketTypePattern _ ts ps -> firstPos ts ps

TypePatternArg (TypeArg t _ _ _ _ _ _) ps -> firstPos [t] ps

instance PosItem VarDecl where

getRange (VarDecl v _ _ p) = firstPos [v] p

instance PosItem TypeArg where

getRange (TypeArg v _ _ _ _ _ p) = firstPos [v] p