{- |

Module : $Header$

Copyright : (c) Uni Bremen 2003

Licence : similar to LGPL, see HetCATS/LICENCE.txt or LIZENZ.txt

Maintainer : hets@tzi.de

Stability : experimental

Portability : non-portable

Translation of the abstract syntax of HasCASL after the static analysis

to the abstract syntax of Haskell.

-}

module ToHaskell.TranslateAna (

-- * Translation of an environment

translateSig

-- * Translation of sentences

, translateSentence

-- * remove dummy decls that are better given by sentences

, cleanSig

) where

import Common.Id

import qualified Common.Lib.Map as Map

import Common.AS_Annotation

import HasCASL.As

import HasCASL.AsUtils

import HasCASL.Le

import SourceNames

import HsName hiding (Id)

import HsDeclStruct

import PropPosSyntax hiding (Id, HsName)

import qualified NewPrettyPrint as HatPretty

import ToHaskell.TranslateId

import ToHaskell.UniqueId

-------------------------------------------------------------------------

-- Translation of an HasCASL-Environement

-------------------------------------------------------------------------

-- | Converts an abstract syntax of HasCASL (after the static analysis)

-- to the top datatype of the abstract syntax of haskell.

translateSig :: Env -> [HsDecl]

translateSig env =

(concat $ map (translateTypeInfo env) $ Map.toList $ typeMap env)

++ (concatMap translateAssump $ distinctOpIds 2 $ Map.toList $ assumps env)

-------------------------------------------------------------------------

-- Translation of types

-------------------------------------------------------------------------

-- | Converts one type to a data or type declaration in Haskell.

translateTypeInfo :: Env -> (TypeId, TypeInfo) -> [HsDecl]

translateTypeInfo env (tid,info) =

let hsname = mkHsIdent UpperId tid

hsTyName = hsTyCon hsname

mkTp l = foldl hsTyApp hsTyName l

loc = toProgPos $ posOfId tid

ddecl = hsDataDecl loc

[] -- empty HsContext

(mkTp $ kindToTypeArgs 1 $ typeKind info)

[HsConDecl loc [] [] hsname []]

derives

in case typeDefn info of

NoTypeDefn -> case superTypes info of

[] -> [ddecl]

[si] -> if isSameId tid si then [ddecl] else

[typeSynonym loc hsTyName si]

si : _ -> [typeSynonym loc hsTyName si]

Supertype _ ts _ ->

[hsTypeDecl loc (mkTp $ getAliasArgs ts) $ getAliasType ts]

AliasTypeDefn ts ->

[hsTypeDecl loc (mkTp $ getAliasArgs ts) $ getAliasType ts]

DatatypeDefn de -> [sentence $ translateDt env de]

_ -> [] -- ignore others

isSameId :: TypeId -> Type -> Bool

isSameId tid (TypeName tid2 _ _) = tid == tid2

isSameId _tid _ty = False

typeSynonym :: SrcLoc -> HsType -> Type -> HsDecl

typeSynonym loc hsname ty =

hsTypeDecl loc hsname (translateType ty)

kindToTypeArgs :: Int -> Kind -> [HsType]

kindToTypeArgs i k = case k of

MissingKind -> []

ClassKind _ rk -> kindToTypeArgs i rk

Downset _ _ rk _ -> kindToTypeArgs i rk

FunKind _ kr _ -> (hsTyVar $ fakeSN $ UnQual ("a" ++ show i))

: kindToTypeArgs (i+1) kr

Intersection l _ -> if null l then []

else kindToTypeArgs i $ head l

ExtKind ek _ _ -> kindToTypeArgs i ek

getAliasArgs :: TypeScheme -> [HsType]

getAliasArgs (TypeScheme arglist _ _) =

map getArg arglist

getArg :: TypeArg -> HsType

getArg (TypeArg tid _ _ _) = hsTyVar $ mkHsIdent LowerId tid

getAliasType :: TypeScheme -> HsType

getAliasType (TypeScheme _ t _) = translateType t

-- | Translation of an alternative constructor for a datatype definition.

translateAltDefn :: Env -> DataPat -> [TypeArg] -> IdMap -> AltDefn

-> [HsConDecl HsType [HsType]]

translateAltDefn env dt args im (Construct muid origTs p _) =

let ts = map (mapType im) origTs in

case muid of

Just uid -> let loc = toProgPos $ posOfId uid

sc = TypeScheme args (getConstrType dt p ts) []

-- resolve overloading

(c, ui) = translateId env uid sc

in case c of

UpperId -> -- no existentials, no context

[HsConDecl loc [] [] ui $

map (HsBangedType . translateType) ts]

_ -> error "ToHaskell.TranslateAna.translateAltDefn"

Nothing -> []

translateDt :: Env -> DataEntry -> Named HsDecl

translateDt env (DataEntry im i _ args alts) =

let j = Map.findWithDefault i i im

loc = toProgPos $ posOfId i

hsname = mkHsIdent UpperId j

hsTyName = hsTyCon hsname

tp = foldl hsTyApp hsTyName $ map getArg args

in

NamedSen ("ga_" ++ showId j "") $

hsDataDecl loc

[] -- empty HsContext

tp

(concatMap (translateAltDefn env (j, args, star)

args im) alts)

derives

-------------------------------------------------------------------------

-- Translation of functions

-------------------------------------------------------------------------

-- | Converts one distinct named function in HasCASL to the corresponding

-- haskell declaration.

-- Generates a definition (Prelude.undefined) for functions that are not

-- defined in HasCASL.

translateAssump :: (Id, OpInfo) -> [HsDecl]

translateAssump (i, opinf) =

let fname = mkHsIdent LowerId i

loc = toProgPos $ posOfId i

res = hsTypeSig loc

[fname] []

$ translateTypeScheme $ opType opinf

in case opDefn opinf of

VarDefn -> []

ConstructData _ -> [] -- wrong case!

_ -> [res, functionUndef loc fname]

-- | Translation of the result type of a typescheme to a haskell type.

-- Uses 'translateType'.

translateTypeScheme :: TypeScheme -> HsType

translateTypeScheme (TypeScheme _ t _) =

translateType t

-- | Translation of types (e.g. product type, type application ...).

translateType :: Type -> HsType

translateType t =

case t of

FunType t1 _arr t2 _ -> hsTyFun (translateType t1) (translateType t2)

ProductType tlist ps -> hsTyTuple (toProgPos $ headPos ps)

$ map translateType tlist

LazyType lt _ -> translateType lt

KindedType kt _kind _ -> translateType kt

TypeAppl t1 t2 -> hsTyApp (translateType t1) (translateType t2)

TypeName tid _kind n ->

if n == 0 then

hsTyCon $ mkHsIdent UpperId tid

else hsTyVar $ mkHsIdent LowerId tid

_ -> error ("translateType: unexpected type: " ++ show t)

toProgPos :: Pos -> SrcLoc

toProgPos p = if isNullPos p then loc0 else let SourcePos n l c = p

in SrcLoc n (1000 + (l-1) * 80 + c) l c

mkHsIdent :: IdCase -> Id -> SN HsName

mkHsIdent c i = SN (UnQual $ translateIdWithType c i)

$ toProgPos $ posOfId i

translateId :: Env -> Id -> TypeScheme -> (IdCase, SN HsName)

translateId env uid sc =

let oid = findUniqueId env uid sc

mkUnQual :: IdCase -> Id -> (IdCase, SN HsName)

mkUnQual c j = (c, mkHsIdent c j)

in case oid of

Just (i, oi) -> if isConstructor oi then mkUnQual UpperId i

else mkUnQual LowerId i

_ -> mkUnQual LowerId uid -- variable

-- | Converts a term in HasCASL to an expression in haskell

translateTerm :: Env -> Term -> HsExp

translateTerm env t =

let loc = toProgPos $ get_pos t in

case t of

QualVar (VarDecl v ty _ _) ->

let (c, i) = translateId env v $ simpleTypeScheme ty in

case c of

LowerId -> rec $ HsId $ HsVar i

_ -> error "translateTerm: variable with UpperId"

QualOp _ (InstOpId uid _ _) sc _ ->

-- The identifier 'uid' may have been renamed. To find its new name,

-- the typescheme 'ts' is tested for unifiability with the

-- typeschemes of the assumps. If an identifier is found, it is used

-- as HsVar or HsCon.

let (c, ui) = translateId env uid sc

in rec $ HsId $ case c of

UpperId -> HsCon ui

LowerId -> HsVar ui

ApplTerm t1 t2 _ ->

rec $ HsApp (translateTerm env t1) $ translateTerm env t2

TupleTerm ts _ -> rec $ HsTuple (map (translateTerm env) ts)

TypedTerm t1 tqual _ty _ -> -- check for global types later

case tqual of

InType -> expUndef loc $ show tqual

_ -> translateTerm env t1

QuantifiedTerm qu _vars _t1 _ -> expUndef loc $ show qu

LambdaTerm pats _part t1 _ ->

rec $ HsLambda

(map (translatePattern env) pats)

(translateTerm env t1)

CaseTerm t1 progeqs _ ->

rec $ HsCase (translateTerm env t1)

(map (translateCaseProgEq env) progeqs)

LetTerm _ progeqs t1 _ ->

rec $ HsLet (map (translateLetProgEq env) progeqs)

(translateTerm env t1)

_ -> error ("translateTerm: unexpected term: " ++ show t)

-- | Conversion of patterns form HasCASL to haskell.

translatePattern :: Env -> Pattern -> HsPat

translatePattern env pat = case pat of

QualVar (VarDecl v ty _ _) ->

if show v == "_" then rec HsPWildCard else

let (c, i) = translateId env v $ simpleTypeScheme ty

in case c of

LowerId -> rec $ HsPId $ HsVar i

_ -> error ("unexpected constructor as variable: " ++ show v)

QualOp _ (InstOpId uid _t _p) sc _ ->

let (_, ui) = translateId env uid sc

in rec $ HsPApp ui []

ApplTerm p1 p2 _ ->

let tp = translatePattern env p1

a = translatePattern env p2

in case struct tp of

HsPApp u os -> rec $ HsPParen $ rec $ HsPApp u (os ++ [a])

HsPParen (Pat (HsPApp u os)) ->

rec $ HsPParen $ rec $ HsPApp u (os ++ [a])

_ -> error ("problematic application pattern " ++ show pat)

TupleTerm pats _ ->

rec $ HsPTuple $ map (translatePattern env) pats

TypedTerm _ InType _ _ -> error "translatePattern InType"

TypedTerm p _ _ty _ -> translatePattern env p

--the type is implicit

AsPattern (VarDecl v ty _ _) p _ ->

let (c, i) = translateId env v $ simpleTypeScheme ty

hp = translatePattern env p

in case c of

LowerId -> rec $ HsPAsPat i hp

_ -> error ("unexpected constructor as @-variable: " ++ show v)

_ -> error ("translatePattern: unexpected pattern: " ++ show pat)

-- | Translation of a program equation of a case term in HasCASL

translateCaseProgEq :: Env -> ProgEq -> HsAlt HsExp HsPat [HsDecl]

translateCaseProgEq env (ProgEq pat t ps) =

HsAlt (toProgPos ps)

(translatePattern env pat)

(HsBody (translateTerm env t))

[]

-- | Translation of a program equation of a let term in HasCASL

translateLetProgEq :: Env -> ProgEq -> HsDecl

translateLetProgEq env (ProgEq pat t ps) =

hsPatBind (toProgPos ps)

(translatePattern env pat)

(HsBody (translateTerm env t))

[]

-- | Translation of a toplevel program equation

translateProgEq :: Env -> ProgEq -> HsDecl

translateProgEq env (ProgEq pat t _) =

let loc = toProgPos $ posOfTerm pat in case getAppl pat of

Just (uid, sc, args) ->

let (_, ui) = translateId env uid sc

in hsFunBind loc [HsMatch loc ui

(map (translatePattern env) args) -- [HsPat]

(HsBody $ translateTerm env t) -- HsRhs

[]]

Nothing -> error ("translateLetProgEq: no toplevel id: " ++ show pat)

-- | remove dummy decls given by sentences

cleanSig :: [HsDecl] -> [Named HsDecl] -> [HsDecl]

cleanSig ds sens =

let dds = foldr ( \ nd l -> case basestruct $ sentence nd of

Just (HsDataDecl _ _ n _ _) -> n : l

_ -> l) [] sens

funs = foldr ( \ nd l -> case basestruct $ sentence nd of

Just (HsFunBind _ (HsMatch _ n _ _ _ : _)) -> n : l

_ -> l) [] sens

in filter ( \ hs -> case basestruct hs of

Just (HsDataDecl _ _ n _ _) -> n `notElem` dds

Just (HsTypeDecl _ n _) -> n `notElem` dds

Just (HsFunBind _ (HsMatch _ n _ _ _ : _)) -> n `notElem` funs

_ -> True)

ds

expUndef :: SrcLoc -> String -> HsExp

expUndef loc s = rec $ HsApp (rec $ HsId $ HsVar $ fakeSN $ UnQual "error")

$ rec $ HsLit loc $ HsString s

-- For the definition of an undefined function.

-- Takes the name of the function as argument.

functionUndef :: SrcLoc -> SN HsName -> HsDecl

functionUndef loc s =

hsFunBind loc [HsMatch loc s [] -- hsPatBind loc (rec $ HsPId $ HsVar s)

(HsBody $ expUndef loc $ HatPretty.pp s)

[]]

translateSentence :: Env -> Named Sentence -> [Named HsDecl]

translateSentence env sen = case sentence sen of

DatatypeSen dt -> map (translateDt env) dt

ProgEqSen _ _ pe -> [NamedSen (senName sen)

$ translateProgEq env pe]

_ -> []

derives :: [SN HsName]

derives = [] -- map (fakeSN . UnQual) ["Show", "Eq", "Ord"]