VarDecl.hs revision f42bcc750a9a02cb4f753b70679f9aacf1b338d7
{- |
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.PrintLe
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 -> Kind -> Id -> State Env Bool
addTypeId warn dfn 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 -> addTypeKind warn dfn i k
-- | check if the kind only misses variance indicators of the known raw kind
isLiberalKind :: ClassMap -> Bool -> RawKind -> Kind -> Maybe Kind
isLiberalKind cm b ok k = case ok of
ClassKind _ -> Just k
FunKind ov fok aok _ -> case k of
FunKind v fk ak ps -> do
nfk <- isLiberalKind cm (not b) fok fk
nak <- isLiberalKind cm b aok ak
return $ FunKind (liberalVariance b ov v) nfk nak ps
ClassKind i -> case Map.lookup i cm of
Just ci -> maybe Nothing (const $ Just k) $ minRawKind "" ok
$ rawKind ci
_ -> Nothing
liberalVariance :: Bool -> Variance -> Variance -> Variance
liberalVariance b v1 v2 = if b then minVariance v1 v2 else
revVariance $ minVariance (revVariance v1) $ revVariance v2
-- | lifted 'anaKindM'
anaKind :: Kind -> State Env RawKind
anaKind k = do
mrk <- fromResult $ anaKindM k . classMap
case mrk of
Nothing -> error "anaKind"
Just rk -> return rk
-- | store type as is (warn on redeclared types)
addTypeKind :: Bool -> TypeDefn -> Id -> Kind -> State Env Bool
addTypeKind warn d i k = do
e <- get
rk <- anaKind k
let tm = typeMap e
cm = classMap e
addTypeSym ck = if Map.member i bTypes then return () else
addSymbol $ idToTypeSymbol e i ck
if placeCount i <= kindArity rk then return () else
addDiags [mkDiag Error "wrong arity of" i]
case Map.lookup i tm of
Nothing -> do
addTypeSym rk
return True
Just (TypeInfo ok oldks sups dfn) ->
case minRawKind "" ok rk of
Nothing -> do
addDiags $ diffKindDiag i ok rk
return False
Just r -> case isLiberalKind cm True r 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
if warn && not isNewInst && case (dfn, d) of
(PreDatatype, DatatypeDefn _) -> False
_ -> True
then addDiags [mkDiag Hint "redeclared type" i]
else return ()
case mDef of
Just newDefn -> do
addTypeSym r
putTypeMap $ Map.insert i (TypeInfo r insts sups newDefn) tm
return True
_ -> do
addDiags $ map (improveDiag i) ds
return False
Nothing -> do
addDiags [mkDiag Error "cannot refine kind" i]
return False
nonUniqueKind :: (GetRange 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 NonVar 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
-- | partition information of an uninstantiated identifier
partitionOpId e i sc =
Set.partition ((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
checkPlaceCount :: Env -> Id -> TypeScheme -> [Diagnosis]
checkPlaceCount e i (TypeScheme _ ty _) =
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 Warning "wrong number of places in" i]
else []
else [mkDiag Warning "expected tuple argument for" i]
else [mkDiag Warning "expected function type for" i]
else []
-- | storing an operation
addOpId :: Id -> TypeScheme -> Set.Set OpAttr -> OpDefn -> State Env Bool
addOpId i oldSc attrs dfn = do
sc@(TypeScheme _ ty _) <- checkUnusedTypevars oldSc
e <- get
let as = assumps e
bs = binders e
ds = checkPlaceCount e i sc
(l, r) = partitionOpId e i sc
oInfo = OpInfo sc attrs dfn
Result es mo = foldM mergeOpInfo oInfo $ Set.toList l
addDiags ds
addDiags $ map (improveDiag i) es
if i `elem` map fst bList then
addDiags [mkDiag Warning "ignoring declaration for builtin identifier" i]
else unless (Set.null l) $ addDiags
[mkDiag Hint ("repeated declaration of '" ++ showId i "' with type") ty]
when (Map.member i bs) $ do
addDiags [mkDiag Warning "identifier shadows binder" i]
putBinders $ Map.delete i bs
case mo of
Nothing -> return False
Just oi -> do
addSymbol $ idToOpSymbol e i $ opType oi
putAssumps $ Map.insert i (Set.insert oi r) as
return True
-- | 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