VarDecl.hs revision ee6c748be810b24e3c70ffd74f291c7394e389f5
{- |
Module : $Header$
Description : analyse var decls
Copyright : (c) Christian Maeder and Uni Bremen 2002-2005
License : similar to LGPL, see HetCATS/LICENSE.txt or LIZENZ.txt
Maintainer : Christian.Maeder@dfki.de
Stability : provisional
Portability : portable
analyse generic var (or type var) decls
-}
module HasCASL.VarDecl where
import Data.Maybe
import Data.List as List
import Control.Monad
import Text.ParserCombinators.Parsec (runParser, eof)
import qualified Data.Map as Map
import qualified Data.Set as Set
import Common.Id
import Common.Lib.State
import Common.Result
import Common.DocUtils
import Common.Lexer
import Common.AnnoState
import HasCASL.ParseTerm
import HasCASL.As
import HasCASL.AsUtils
import HasCASL.FoldType
import HasCASL.Le
import HasCASL.ClassAna
import HasCASL.TypeAna
import HasCASL.Unify
import HasCASL.Merge
import HasCASL.Builtin
anaStarType :: Type -> State Env (Maybe Type)
anaStarType t = fmap (fmap snd) $ anaType (Just universe, t)
anaType :: (Maybe Kind, Type)
-> State Env (Maybe ((RawKind, Set.Set Kind), Type))
anaType p = fromResult $ anaTypeM p
anaTypeScheme :: TypeScheme -> State Env (Maybe TypeScheme)
anaTypeScheme (TypeScheme tArgs ty p) =
do tvs <- gets localTypeVars -- save global variables
mArgs <- mapM anaddTypeVarDecl tArgs
let newArgs = catMaybes mArgs
mt <- anaStarType ty
case mt of
Nothing -> do putLocalTypeVars tvs -- forget local variables
return Nothing
Just newTy -> do
let newSc = TypeScheme newArgs newTy p
gTy <- generalizeS newSc
putLocalTypeVars tvs -- forget local variables
return $ Just gTy
generalizeS :: TypeScheme -> State Env TypeScheme
generalizeS sc@(TypeScheme tArgs ty p) = do
let fvs = leaves (> 0) ty
svs = sortBy comp fvs
comp a b = compare (fst a) $ fst b
tvs <- gets localTypeVars
let newArgs = map ( \ (_, (i, _)) -> case Map.lookup i tvs of
Nothing -> error "generalizeS"
Just (TypeVarDefn v vk rk c) ->
TypeArg i v vk rk c Other nullRange) svs
newSc = TypeScheme (genTypeArgs newArgs) (generalize newArgs ty) p
if null tArgs then return newSc
else do
addDiags $ generalizable False sc
return newSc
-- | store type id and check kind arity (warn on redeclared types)
addTypeId :: Bool -> TypeDefn -> RawKind -> Kind -> Id -> State Env Bool
addTypeId warn dfn rk k i = do
tvs <- gets localTypeVars
case Map.lookup i tvs of
Just _ -> do
if warn then addDiags[mkDiag Warning
"new type shadows type variable" i]
else return ()
putLocalTypeVars $ Map.delete i tvs
Nothing -> return()
cm <- gets classMap
case Map.lookup i cm of
Just _ -> do
addDiags [mkDiag Error "class name used as type" i]
return False
Nothing -> if placeCount i <= kindArity rk then do
addTypeKind warn dfn i rk k
return True
else do addDiags [mkDiag Error "wrong arity of" i]
return False
-- | check if the kind only misses variance indicators of the known raw kind
isLiberalKind :: ClassMap -> RawKind -> Kind -> Maybe Kind
isLiberalKind cm ok k = case ok of
ClassKind _ -> Just k
FunKind ov fok aok _ -> case k of
FunKind v fk ak ps | v == ov || elem InVar [v, ov] -> do
nfk <- isLiberalKind cm fok fk
nak <- isLiberalKind cm aok ak
return $ FunKind (if ov == InVar then v else ov) nfk nak ps
ClassKind i -> case Map.lookup i cm of
Just ci -> maybe Nothing (const $ Just k) $ minRawKind "" ok
$ rawKind ci
_ -> Nothing
_ -> Nothing
-- | store type as is (warn on redeclared types)
addTypeKind :: Bool -> TypeDefn -> Id -> RawKind -> Kind
-> State Env Bool
addTypeKind warn d i rk k =
do tm <- gets typeMap
cm <- gets classMap
case Map.lookup i tm of
Nothing -> do
putTypeMap $ Map.insert i (TypeInfo rk (Set.singleton k)
Set.empty d) tm
return True
Just (TypeInfo ok oldks sups dfn) -> case isLiberalKind cm ok k of
Just nk -> do
let isNewInst = newKind cm nk oldks
insts = if isNewInst then addNewKind cm nk oldks
else oldks
Result ds mDef = mergeTypeDefn dfn d
Result es mk = minRawKind (show i) ok rk
if warn && not isNewInst && case (dfn, d) of
(PreDatatype, DatatypeDefn _) -> False
_ -> True then
addDiags [mkDiag Hint "redeclared type" i]
else return ()
case (mDef, mk) of
(Just newDefn, Just r) -> do
putTypeMap $ Map.insert i
(TypeInfo r insts sups newDefn) tm
return True
_ -> do
addDiags $ map (improveDiag i) $ es ++ ds
return False
Nothing -> do
addDiags $ diffKindDiag i ok rk
return False
nonUniqueKind :: (PosItem a, Pretty a) => Set.Set Kind -> a ->
(Kind -> State Env (Maybe b)) -> State Env (Maybe b)
nonUniqueKind ks a f = case Set.toList ks of
[k] -> f k
_ -> do addDiags [mkDiag Error "non-unique kind for" a]
return Nothing
-- | analyse a type argument
anaddTypeVarDecl :: TypeArg -> State Env (Maybe TypeArg)
anaddTypeVarDecl (TypeArg i v vk _ _ s ps) = do
cm <- gets classMap
case Map.lookup i cm of
Just _ -> do
addDiags [mkDiag Error "class used as type variable" i]
return Nothing
Nothing -> do
c <- toEnvState inc
case vk of
VarKind k ->
let Result ds (Just rk) = anaKindM k cm
in if null ds then do
addLocalTypeVar True (TypeVarDefn v vk rk c) i
return $ Just $ TypeArg i v vk rk c s ps
else do addDiags ds
return Nothing
Downset t -> do
mt <- anaType (Nothing, t)
case mt of
Nothing -> return Nothing
Just ((rk, ks), nt) ->
nonUniqueKind ks t $ \ k -> do
let nd = Downset (KindedType nt (Set.singleton k) nullRange)
addLocalTypeVar True (TypeVarDefn InVar nd rk c) i
return $ Just $ TypeArg i v (Downset nt) rk c s ps
MissingKind -> do
tvs <- gets localTypeVars
case Map.lookup i tvs of
Nothing -> do
addDiags [mkDiag Error "unknown type variable" i]
let dvk = VarKind universe
addLocalTypeVar True (TypeVarDefn v dvk rStar c) i
return $ Just $ TypeArg i v dvk rStar c s ps
Just (TypeVarDefn v0 dvk rk _) -> do
addLocalTypeVar False (TypeVarDefn v0 dvk rk c) i
return $ Just $ TypeArg i v0 dvk rk c s ps
-- | get matching information of uninstantiated identifier
findOpId :: Env -> Id -> TypeScheme -> Maybe OpInfo
findOpId e i sc = listToMaybe $ Set.toList $ fst $ partitionOpId e i sc
-- | partition information of an uninstantiated identifier
partitionOpId e i sc =
Set.partition (isUnifiable (typeMap e) (counter e) sc . opType)
$ Map.findWithDefault Set.empty i $ assumps e
checkUnusedTypevars :: TypeScheme -> State Env TypeScheme
checkUnusedTypevars sc@(TypeScheme tArgs t ps) = do
let ls = map (fst . snd) $ leaves (< 0) t -- generic vars
rest = map getTypeVar tArgs List.\\ ls
if null rest then return ()
else addDiags [Diag Warning ("unused type variables: "
++ show(ppWithCommas rest)) ps]
return sc
-- | storing an operation
addOpId :: Id -> TypeScheme -> Set.Set OpAttr -> OpDefn -> State Env Bool
addOpId i oldSc attrs dfn =
do sc <- checkUnusedTypevars oldSc
e <- get
let as = assumps e
tm = typeMap e
cm = classMap e
TypeScheme args1 ty _ = sc
ds = if placeCount i > 1 then
let (fty, fargs) = getTypeAppl ty in
if length fargs == 2 &&
lesserType e fty (toFunType PFunArr) then
let (pty, ts) = getTypeAppl (head fargs)
n = length ts in
if n > 1 && lesserType e pty (toProdType n nullRange) then
if placeCount i /= n then
[mkDiag Error "wrong number of places in" i]
else []
else [mkDiag Error "expected tuple argument for" i]
else [mkDiag Error "expected function type for" i]
else []
(l, r) = partitionOpId e i sc
oInfo = OpInfo sc attrs dfn
if null ds then
do let Result es mo = foldM (mergeOpInfo cm tm) oInfo
$ Set.toList l
addDiags $ map (improveDiag i) es
if i `elem` map fst bList then addDiags [mkDiag Warning
"ignoring declaration for builtin identifier" i]
else case Set.toList l of
[] -> return ()
[OpInfo {opType = TypeScheme args2 ty2 _}]
| eqStrippedType ty2 ty -> addDiags [mkDiag Hint
((if args1 == args2 then "repeated" else
if specializedScheme cm args2 args1
then "more general" else
if specializedScheme cm args1 args2 then
"ignored specialized" else "uncomparable")
++ " declaration of '"
++ showId i "' with type") ty]
_ -> addDiags [mkDiag Warning
"overlapping declaration of" i]
case mo of
Nothing -> return False
Just oi -> do
putAssumps $ Map.insert i (Set.insert oi r) as
return True
else do addDiags ds
return False
-- | add a local variable with an analysed type (if True then warn)
addLocalVar :: Bool -> VarDecl -> State Env ()
addLocalVar warn (VarDecl v t _ _) =
do ass <- gets assumps
vs <- gets localVars
if warn then if Map.member v ass then
addDiags [mkDiag Hint "variable shadows global name(s)" v]
else if Map.member v vs then
addDiags [mkDiag Hint "rebound variable" v]
else return ()
else return ()
putLocalVars $ Map.insert v (VarDefn t) vs
-- | add analysed local variable or type variable declaration
addGenVarDecl :: GenVarDecl -> State Env ()
addGenVarDecl(GenVarDecl v) = addLocalVar True v
addGenVarDecl(GenTypeVarDecl t) = addTypeVarDecl False t
-- | analyse and add local variable or type variable declaration
anaddGenVarDecl :: Bool -> GenVarDecl -> State Env (Maybe GenVarDecl)
anaddGenVarDecl warn gv = case gv of
GenVarDecl v -> optAnaddVarDecl warn v
GenTypeVarDecl t -> anaddTypeVarDecl t >>= (return . fmap GenTypeVarDecl)
convTypeToKind :: Type -> Maybe (Variance, Kind)
convTypeToKind ty = let s = showDoc ty "" in
case runParser (extKind << eof) (emptyAnnos ()) "" s of
Right (v, k) -> Just (v, k)
_ -> Nothing
convertTypeToKind :: Env -> Type -> Result (Variance, Kind)
convertTypeToKind e ty = case convTypeToKind ty of
Just (v, k) -> let Result ds _ = anaKindM k $ classMap e in
if null ds then return (v, k) else Result ds Nothing
_ -> fail $ "not a kind '" ++ showDoc ty "'"
-- | local variable or type variable declaration
optAnaddVarDecl :: Bool -> VarDecl -> State Env (Maybe GenVarDecl)
optAnaddVarDecl warn vd@(VarDecl v t s q) =
let varDecl = do mvd <- anaVarDecl vd
case mvd of
Nothing -> return Nothing
Just nvd -> do
let movd = makeMonomorph nvd
addLocalVar warn movd
return $ Just $ GenVarDecl movd
in if isSimpleId v then
do e <- get
let Result ds mk = convertTypeToKind e t
case mk of
Just (vv, k) -> do
addDiags [mkDiag Hint "is type variable" v]
tv <- anaddTypeVarDecl $ TypeArg v vv (VarKind k) rStar 0 s q
return $ fmap GenTypeVarDecl tv
_ -> do addDiags $ map ( \ d -> Diag Hint (diagString d) q) ds
varDecl
else varDecl
makeMonomorph :: VarDecl -> VarDecl
makeMonomorph (VarDecl v t sk ps) = VarDecl v (monoType t) sk ps
monoType :: Type -> Type
monoType = foldType mapTypeRec
{ foldTypeName = \ t i k n -> if n > 0 then TypeName i k 0 else t }
-- | analyse variable declaration
anaVarDecl :: VarDecl -> State Env (Maybe VarDecl)
anaVarDecl(VarDecl v oldT sk ps) =
do mt <- anaStarType oldT
return $ case mt of
Nothing -> Nothing
Just t -> Just $ VarDecl v t sk ps