vdefgs
return (eextend globalEnv
(mn,Envs{tcenv_=tcenv,tsenv_=tsenv,cenv_=cenv,venv_=e_venv})))
- (mn, globalEnv)
+ -- avoid name shadowing
+ (mn, eremove globalEnv mn)
-- Like checkModule, but doesn't typecheck the code, instead just
-- returning declared types for top-level defns.
checkVdefg :: Bool -> (Tcenv,Tsenv,Tvenv,Cenv) -> (Venv,Venv)
-> Vdefg -> CheckResult (Venv,Venv)
-checkVdefg top_level (tcenv,tsenv,tvenv,cenv) (e_venv,l_venv) vdefg =
+checkVdefg top_level (tcenv,tsenv,tvenv,cenv) (e_venv,l_venv) vdefg = do
+ mn <- getMname
case vdefg of
Rec vdefs ->
- do e_venv' <- foldM extendVenv e_venv e_vts
- l_venv' <- foldM extendVenv l_venv l_vts
+ do (e_venv', l_venv') <- makeEnv mn vdefs
let env' = (tcenv,tsenv,tvenv,cenv,e_venv',l_venv')
- mapM_ (\ (vdef@(Vdef ((m,_),t,e))) ->
- do mn <- getMname
- requireModulesEq m mn "value definition" vdef True
- k <- checkTy (tcenv,tvenv) t
- require (k `eqKind` Klifted) ("unlifted kind in:\n" ++ show vdef)
- t' <- checkExp env' e
- requireM (equalTy tsenv t t')
- ("declared type doesn't match expression type in:\n" ++ show vdef ++ "\n" ++
- "declared type: " ++ show t ++ "\n" ++
- "expression type: " ++ show t')) vdefs
- return (e_venv',l_venv')
- where e_vts = [ (v,t) | Vdef ((Just _,v),t,_) <- vdefs ]
- l_vts = [ (v,t) | Vdef ((Nothing,v),t,_) <- vdefs]
- Nonrec (vdef@(Vdef ((m,v),t,e))) ->
- do mn <- getMname
- -- TODO: document this weirdness
- let isZcMain = vdefIsMainWrapper mn m
- unless isZcMain $
- requireModulesEq m mn "value definition" vdef True
- k <- checkTy (tcenv,tvenv) t
- require (not (k `eqKind` Kopen)) ("open kind in:\n" ++ show vdef)
- require ((not top_level) || (not (k `eqKind` Kunlifted)))
- ("top-level unlifted kind in:\n" ++ show vdef)
- t' <- checkExp (tcenv,tsenv,tvenv,cenv,e_venv,l_venv) e
- requireM (equalTy tsenv t t')
- ("declared type doesn't match expression type in:\n"
- ++ show vdef ++ "\n" ++
- "declared type: " ++ show t ++ "\n" ++
- "expression type: " ++ show t')
- if isNothing m then
- do l_venv' <- extendVenv l_venv (v,t)
- return (e_venv,l_venv')
- else
- -- awful, but avoids name shadowing --
- -- otherwise we'd have two bindings for "main"
- do e_venv' <- if isZcMain
- then return e_venv
- else extendVenv e_venv (v,t)
- return (e_venv',l_venv)
+ mapM_ (checkVdef (\ vdef k -> require (k `eqKind` Klifted)
+ ("unlifted kind in:\n" ++ show vdef)) env')
+ vdefs
+ return (e_venv', l_venv')
+ Nonrec vdef ->
+ do let env' = (tcenv, tsenv, tvenv, cenv, e_venv, l_venv)
+ checkVdef (\ vdef k -> do
+ require (not (k `eqKind` Kopen)) ("open kind in:\n" ++ show vdef)
+ require ((not top_level) || (not (k `eqKind` Kunlifted)))
+ ("top-level unlifted kind in:\n" ++ show vdef)) env' vdef
+ makeEnv mn [vdef]
+
+ where makeEnv mn vdefs = do
+ ev <- foldM extendVenv e_venv e_vts
+ lv <- foldM extendVenv l_venv l_vts
+ return (ev, lv)
+ where e_vts = [ (v,t) | Vdef ((Just m,v),t,_) <- vdefs,
+ not (vdefIsMainWrapper mn (Just m))]
+ l_vts = [ (v,t) | Vdef ((Nothing,v),t,_) <- vdefs]
+ checkVdef checkKind env (vdef@(Vdef ((m,_),t,e))) = do
+ mn <- getMname
+ let isZcMain = vdefIsMainWrapper mn m
+ unless isZcMain $
+ requireModulesEq m mn "value definition" vdef True
+ k <- checkTy (tcenv,tvenv) t
+ checkKind vdef k
+ t' <- checkExp env e
+ requireM (equalTy tsenv t t')
+ ("declared type doesn't match expression type in:\n"
+ ++ show vdef ++ "\n" ++
+ "declared type: " ++ show t ++ "\n" ++
+ "expression type: " ++ show t')
vdefIsMainWrapper :: AnMname -> Mname -> Bool
vdefIsMainWrapper enclosing defining =
return t
c@(Cast e t) ->
do eTy <- ch e
- k <- checkTy (tcenv,tvenv) t
- case k of
- (Keq fromTy toTy) -> do
- require (eTy == fromTy) ("Type mismatch in cast: c = "
- ++ show c ++ " and " ++ show eTy
- ++ " and " ++ show fromTy)
- return toTy
- _ -> fail ("Cast with non-equality kind: " ++ show e
- ++ " and " ++ show t ++ " has kind " ++ show k)
+ (fromTy, toTy) <- checkTyCo (tcenv,tvenv) t
+ require (eTy == fromTy) ("Type mismatch in cast: c = "
+ ++ show c ++ "\nand eTy = " ++ show eTy
+ ++ "\n and " ++ show fromTy)
+ return toTy
Note _ e ->
ch e
External _ t ->
checkExp env e
checkTy :: (Tcenv,Tvenv) -> Ty -> CheckResult Kind
-checkTy es@(tcenv,tvenv) t = ch t
+checkTy es@(tcenv,tvenv) = ch
where
ch (Tvar tv) = lookupM tvenv tv
ch (Tcon qtc) = do
-- :Co:TTypeable2 (->)
-- where in this case, :Co:TTypeable2 expects an
-- argument of kind (*->(*->*)) and (->) has kind
- -- (?->(?->*)). In general, I don't think it's
+ -- (?->(?->*)). I'm not sure whether or not it's
-- sound to apply an arbitrary coercion to an
-- argument that's a subkind of what it expects.
then warn $ "Applying coercion " ++ show tc ++
return $ Keq (substl tvs tys from) (substl tvs tys to)
Nothing -> checkTapp t1 t2
where checkTapp t1 t2 = do
- k1 <- ch t1
+ k1 <- ch t1
k2 <- ch t2
case k1 of
- Karrow k11 k12 ->
- case k2 of
- Keq eqTy1 eqTy2 -> do
- -- Distribute the type operator over the
- -- coercion
- subK1 <- checkTy es eqTy1
- subK2 <- checkTy es eqTy2
- require (subK2 `subKindOf` k11 &&
- subK1 `subKindOf` k11) $
- kindError
- return $ Keq (Tapp t1 eqTy1) (Tapp t1 eqTy2)
- _ -> do
- require (k2 `subKindOf` k11) kindError
- return k12
+ Karrow k11 k12 -> do
+ require (k2 `subKindOf` k11) kindError
+ return k12
where kindError =
"kinds don't match in type application: "
++ show t ++ "\n" ++
ch (Tforall tb t) =
do tvenv' <- extendTvenv tvenv tb
- k <- checkTy (tcenv,tvenv') t
- return $ case k of
- -- distribute the forall
- Keq t1 t2 -> Keq (Tforall tb t1) (Tforall tb t2)
- _ -> k
+ checkTy (tcenv,tvenv') t
ch (TransCoercion t1 t2) = do
- k1 <- checkTy es t1
- k2 <- checkTy es t2
- case (k1, k2) of
- (Keq ty1 ty2, Keq ty3 ty4) | ty2 == ty3 ->
- return $ Keq ty1 ty4
- _ -> fail ("Bad kinds in trans. coercion: " ++
- show k1 ++ " " ++ show k2)
+ (ty1,ty2) <- checkTyCo es t1
+ (ty3,ty4) <- checkTyCo es t2
+ require (ty2 == ty3) ("Types don't match in trans. coercion: " ++
+ show ty2 ++ " and " ++ show ty3)
+ return $ Keq ty1 ty4
ch (SymCoercion t1) = do
- k <- checkTy es t1
- case k of
- Keq ty1 ty2 -> return $ Keq ty2 ty1
- _ -> fail ("Bad kind in sym. coercion: "
- ++ show k)
+ (ty1,ty2) <- checkTyCo es t1
+ return $ Keq ty2 ty1
ch (UnsafeCoercion t1 t2) = do
checkTy es t1
checkTy es t2
return $ Keq t1 t2
ch (LeftCoercion t1) = do
- k <- checkTy es t1
+ k <- checkTyCo es t1
case k of
- Keq (Tapp u _) (Tapp w _) -> return $ Keq u w
+ ((Tapp u _), (Tapp w _)) -> return $ Keq u w
_ -> fail ("Bad coercion kind in operand of left: " ++ show k)
ch (RightCoercion t1) = do
- k <- checkTy es t1
+ k <- checkTyCo es t1
case k of
- Keq (Tapp _ v) (Tapp _ x) -> return $ Keq v x
+ ((Tapp _ v), (Tapp _ x)) -> return $ Keq v x
_ -> fail ("Bad coercion kind in operand of left: " ++ show k)
+ ch (InstCoercion ty arg) = do
+ forallK <- checkTyCo es ty
+ case forallK of
+ ((Tforall (v1,k1) b1), (Tforall (v2,k2) b2)) -> do
+ require (k1 `eqKind` k2) ("Kind mismatch in argument of inst: "
+ ++ show ty)
+ argK <- checkTy es arg
+ require (argK `eqKind` k1) ("Kind mismatch in type being "
+ ++ "instantiated: " ++ show arg)
+ let newLhs = substl [v1] [arg] b1
+ let newRhs = substl [v2] [arg] b2
+ return $ Keq newLhs newRhs
+ _ -> fail ("Non-forall-ty in argument to inst: " ++ show ty)
+
+checkTyCo :: (Tcenv, Tvenv) -> Ty -> CheckResult (Ty, Ty)
+checkTyCo es@(tcenv,_) t@(Tapp t1 t2) =
+ (case splitTyConApp_maybe t of
+ Just (tc, tys) -> do
+ tcK <- qlookupM tcenv_ tcenv eempty tc
+ case tcK of
+ -- todo: avoid duplicating this code
+ -- blah, this almost calls for a different syntactic form
+ -- (for a defined-coercion app): (TCoercionApp Tcon [Ty])
+ Coercion (DefinedCoercion tbs (from, to)) -> do
+ require (length tys == length tbs) $
+ ("Arity mismatch in coercion app: " ++ show t)
+ let (tvs, tks) = unzip tbs
+ argKs <- mapM (checkTy es) tys
+ let kPairs = zip argKs tks
+ let kindsOk = all (uncurry eqKind) kPairs
+ if not kindsOk &&
+ all (uncurry subKindOf) kPairs
+ -- see comments in checkTy about this
+ then warn $ "Applying coercion " ++ show tc ++
+ " to arguments of kind " ++ show argKs
+ ++ " when it expects: " ++ show tks
+ else require kindsOk
+ ("Kind mismatch in coercion app: " ++ show tks
+ ++ " and " ++ show argKs ++ " t = " ++ show t)
+ return (substl tvs tys from, substl tvs tys to)
+ _ -> checkTapp t1 t2
+ _ -> checkTapp t1 t2)
+ where checkTapp t1 t2 = do
+ (lhsRator, rhsRator) <- checkTyCo es t1
+ (lhs, rhs) <- checkTyCo es t2
+ -- Comp rule from paper
+ checkTy es (Tapp lhsRator lhs)
+ checkTy es (Tapp rhsRator rhs)
+ return (Tapp lhsRator lhs, Tapp rhsRator rhs)
+checkTyCo (tcenv, tvenv) (Tforall tb t) = do
+ tvenv' <- extendTvenv tvenv tb
+ (t1,t2) <- checkTyCo (tcenv, tvenv') t
+ return (Tforall tb t1, Tforall tb t2)
+checkTyCo es t = do
+ k <- checkTy es t
+ case k of
+ Keq t1 t2 -> return (t1, t2)
+ -- otherwise, expand by the "refl" rule
+ _ -> return (t, t)
{- Type equality modulo newtype synonyms. -}
equalTy :: Tsenv -> Ty -> Ty -> CheckResult Bool
expand (RightCoercion t1) = do
exp1 <- expand t1
return $ RightCoercion exp1
+ expand (InstCoercion t1 t2) = do
+ exp1 <- expand t1
+ exp2 <- expand t2
+ return $ InstCoercion exp1 exp2
expapp (t@(Tcon (m,tc))) ts =
do env <- mlookupM tsenv_ tsenv eempty m
case elookup env tc of
UnsafeCoercion t1 t2 -> UnsafeCoercion (f env t1) (f env t2)
LeftCoercion t1 -> LeftCoercion (f env t1)
RightCoercion t1 -> RightCoercion (f env t1)
+ InstCoercion t1 t2 -> InstCoercion (f env t1) (f env t2)
where free = foldr union [] (map (freeTvars.snd) env)
t' = freshTvar free
freeTvars :: Ty -> [Tvar]
freeTvars (Tcon _) = []
freeTvars (Tvar v) = [v]
-freeTvars (Tapp t1 t2) = (freeTvars t1) `union` (freeTvars t2)
+freeTvars (Tapp t1 t2) = freeTvars t1 `union` freeTvars t2
freeTvars (Tforall (t,_) t1) = delete t (freeTvars t1)
freeTvars (TransCoercion t1 t2) = freeTvars t1 `union` freeTvars t2
freeTvars (SymCoercion t) = freeTvars t
freeTvars (UnsafeCoercion t1 t2) = freeTvars t1 `union` freeTvars t2
freeTvars (LeftCoercion t) = freeTvars t
freeTvars (RightCoercion t) = freeTvars t
+freeTvars (InstCoercion t1 t2) = freeTvars t1 `union` freeTvars t2
{- Return any tvar *not* in the argument list. -}
freshTvar :: [Tvar] -> Tvar
projects / ghc-hetmet.git / blobdiff