--
-----------------------------------------------------------------------------
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings
--- for details
-
module RtClosureInspect(
cvObtainTerm, -- :: HscEnv -> Int -> Bool -> Maybe Type -> HValue -> IO Term
pprTerm,
cPprTerm,
cPprTermBase,
+ CustomTermPrinter,
termType,
foldTerm,
TermFold(..),
import HscTypes ( HscEnv )
import Linker
-import DataCon
-import Type
-import TcRnMonad ( TcM, initTc, ioToTcRn,
- tryTcErrs)
+import DataCon
+import Type
+import Var
+import TcRnMonad ( TcM, initTc, ioToTcRn,
+ tryTcErrs, traceTc)
import TcType
import TcMType
import TcUnify
import TcGadt
import TcEnv
import DriverPhases
-import TyCon
-import Name
+import TyCon
+import Name
import VarEnv
import Util
import VarSet
-import TysPrim
+import TysPrim
import PrelNames
import TysWiredIn
import Control.Monad
import Data.Maybe
import Data.Array.Base
+import Data.Ix
import Data.List ( partition )
import qualified Data.Sequence as Seq
import Data.Monoid
data Term = Term { ty :: Type
, dc :: Either String DataCon
- -- The heap datacon. If ty is a newtype,
- -- this is NOT the newtype datacon.
-- Empty if the datacon aint exported by the .hi
-- (private constructors in -O0 libraries)
, val :: HValue
, val :: HValue
, bound_to :: Maybe Name -- Useful for printing
}
+ | NewtypeWrap{ ty :: Type
+ , dc :: Either String DataCon
+ , wrapped_term :: Term }
-isTerm, isSuspension, isPrim :: Term -> Bool
+isTerm, isSuspension, isPrim, isNewtypeWrap :: Term -> Bool
isTerm Term{} = True
isTerm _ = False
isSuspension Suspension{} = True
isSuspension _ = False
isPrim Prim{} = True
isPrim _ = False
+isNewtypeWrap NewtypeWrap{} = True
+isNewtypeWrap _ = False
termType :: Term -> Maybe Type
termType t@(Suspension {}) = mb_ty t
isFullyEvaluatedTerm :: Term -> Bool
isFullyEvaluatedTerm Term {subTerms=tt} = all isFullyEvaluatedTerm tt
-isFullyEvaluatedTerm Suspension {} = False
isFullyEvaluatedTerm Prim {} = True
+isFullyEvaluatedTerm NewtypeWrap{wrapped_term=t} = isFullyEvaluatedTerm t
+isFullyEvaluatedTerm _ = False
instance Outputable (Term) where
ppr = head . cPprTerm cPprTermBase
#include "../includes/ClosureTypes.h"
+aP_CODE, pAP_CODE :: Int
aP_CODE = AP
pAP_CODE = PAP
#undef AP
getClosureData a =
case unpackClosure# a of
(# iptr, ptrs, nptrs #) -> do
+#ifndef GHCI_TABLES_NEXT_TO_CODE
+ -- the info pointer we get back from unpackClosure# is to the
+ -- beginning of the standard info table, but the Storable instance
+ -- for info tables takes into account the extra entry pointer
+ -- when !tablesNextToCode, so we must adjust here:
+ itbl <- peek (Ptr iptr `plusPtr` negate wORD_SIZE)
+#else
itbl <- peek (Ptr iptr)
+#endif
let tipe = readCType (BCI.tipe itbl)
elems = fromIntegral (BCI.ptrs itbl)
ptrsList = Array 0 (elems - 1) elems ptrs
nptrs_data = [W# (indexWordArray# nptrs i)
| I# i <- [0.. fromIntegral (BCI.nptrs itbl)] ]
- ASSERT(fromIntegral elems >= 0) return ()
+ ASSERT(elems >= 0) return ()
ptrsList `seq`
return (Closure tipe (Ptr iptr) itbl ptrsList nptrs_data)
case tipe closure of
Constr -> do are_subs_evaluated <- amapM isFullyEvaluated (ptrs closure)
return$ and are_subs_evaluated
- otherwise -> return False
+ _ -> return False
where amapM f = sequence . amap' f
+amap' :: (t -> b) -> Array Int t -> [b]
amap' f (Array i0 i _ arr#) = map g [0 .. i - i0]
where g (I# i#) = case indexArray# arr# i# of
(# e #) -> f e
| (x, rest) <- splitAt ((sizeofType t + wORD_SIZE - 1) `div` wORD_SIZE) xx
= x : go tt rest
+sizeofTyCon :: TyCon -> Int
sizeofTyCon = sizeofPrimRep . tyConPrimRep
-----------------------------------
-- * Traversals for Terms
-----------------------------------
+type TermProcessor a b = Type -> Either String DataCon -> HValue -> [a] -> b
-data TermFold a = TermFold { fTerm :: Type -> Either String DataCon -> HValue -> [a] -> a
+data TermFold a = TermFold { fTerm :: TermProcessor a a
, fPrim :: Type -> [Word] -> a
, fSuspension :: ClosureType -> Maybe Type -> HValue
-> Maybe Name -> a
+ , fNewtypeWrap :: Type -> Either String DataCon
+ -> a -> a
}
foldTerm :: TermFold a -> Term -> a
foldTerm tf (Term ty dc v tt) = fTerm tf ty dc v (map (foldTerm tf) tt)
foldTerm tf (Prim ty v ) = fPrim tf ty v
foldTerm tf (Suspension ct ty v b) = fSuspension tf ct ty v b
+foldTerm tf (NewtypeWrap ty dc t) = fNewtypeWrap tf ty dc (foldTerm tf t)
idTermFold :: TermFold Term
idTermFold = TermFold {
fTerm = Term,
fPrim = Prim,
- fSuspension = Suspension
+ fSuspension = Suspension,
+ fNewtypeWrap = NewtypeWrap
}
idTermFoldM :: Monad m => TermFold (m Term)
idTermFoldM = TermFold {
fTerm = \ty dc v tt -> sequence tt >>= return . Term ty dc v,
fPrim = (return.). Prim,
- fSuspension = (((return.).).). Suspension
+ fSuspension = (((return.).).). Suspension,
+ fNewtypeWrap= \ty dc t -> NewtypeWrap ty dc `liftM` t
}
mapTermType :: (Type -> Type) -> Term -> Term
mapTermType f = foldTerm idTermFold {
fTerm = \ty dc hval tt -> Term (f ty) dc hval tt,
fSuspension = \ct mb_ty hval n ->
- Suspension ct (fmap f mb_ty) hval n }
+ Suspension ct (fmap f mb_ty) hval n,
+ fNewtypeWrap= \ty dc t -> NewtypeWrap (f ty) dc t}
termTyVars :: Term -> TyVarSet
termTyVars = foldTerm TermFold {
tyVarsOfType ty `plusVarEnv` concatVarEnv tt,
fSuspension = \_ mb_ty _ _ ->
maybe emptyVarEnv tyVarsOfType mb_ty,
- fPrim = \ _ _ -> emptyVarEnv }
+ fPrim = \ _ _ -> emptyVarEnv,
+ fNewtypeWrap= \ty _ t -> tyVarsOfType ty `plusVarEnv` t}
where concatVarEnv = foldr plusVarEnv emptyVarEnv
+
----------------------------------
-- Pretty printing of terms
----------------------------------
+type Precedence = Int
+type TermPrinter = Precedence -> Term -> SDoc
+type TermPrinterM m = Precedence -> Term -> m SDoc
+
app_prec,cons_prec ::Int
app_prec = 10
cons_prec = 5 -- TODO Extract this info from GHC itself
-pprTerm y p t | Just doc <- pprTermM y p t = doc
+pprTerm :: TermPrinter -> TermPrinter
+pprTerm y p t | Just doc <- pprTermM (\p -> Just . y p) p t = doc
+pprTerm _ _ _ = panic "pprTerm"
-pprTermM :: Monad m => (Int -> Term -> m SDoc) -> Int -> Term -> m SDoc
-pprTermM y p t@Term{dc=Left dc_tag, subTerms=tt, ty=ty} = do
+pprTermM, ppr_termM, pprNewtypeWrap :: Monad m => TermPrinterM m -> TermPrinterM m
+pprTermM y p t = pprDeeper `liftM` ppr_termM y p t
+
+pprTermM1, ppr_termM1 :: Monad m => Term -> m SDoc
+pprTermM1 t = pprDeeper `liftM` ppr_termM1 t
+
+ppr_termM y p Term{dc=Left dc_tag, subTerms=tt} = do
tt_docs <- mapM (y app_prec) tt
- return$ cparen (not(null tt) && p >= app_prec) (text dc_tag <+> sep tt_docs)
+ return$ cparen (not(null tt) && p >= app_prec) (text dc_tag <+> pprDeeperList fsep tt_docs)
-pprTermM y p t@Term{dc=Right dc, subTerms=tt, ty=ty}
+ppr_termM y p Term{dc=Right dc, subTerms=tt}
{- | dataConIsInfix dc, (t1:t2:tt') <- tt --TODO fixity
- = parens (pprTerm1 True t1 <+> ppr dc <+> pprTerm1 True ppr t2)
- <+> hsep (map (pprTerm1 True) tt)
+ = parens (ppr_term1 True t1 <+> ppr dc <+> ppr_term1 True ppr t2)
+ <+> hsep (map (ppr_term1 True) tt)
-} -- TODO Printing infix constructors properly
| null tt = return$ ppr dc
- | Just (tc,_) <- splitNewTyConApp_maybe ty
- , isNewTyCon tc
- , Just new_dc <- maybeTyConSingleCon tc = do
- real_value <- y 10 t{ty=repType ty}
- return$ cparen (p >= app_prec) (ppr new_dc <+> real_value)
| otherwise = do
tt_docs <- mapM (y app_prec) tt
- return$ cparen (p >= app_prec) (ppr dc <+> sep tt_docs)
+ return$ cparen (p >= app_prec) (ppr dc <+> pprDeeperList fsep tt_docs)
+
+ppr_termM y p t@NewtypeWrap{} = pprNewtypeWrap y p t
+
+ppr_termM _ _ t = ppr_termM1 t
-pprTermM y _ t = pprTermM1 y t
-pprTermM1 _ Prim{value=words, ty=ty} =
+
+ppr_termM1 Prim{value=words, ty=ty} =
return$ text$ repPrim (tyConAppTyCon ty) words
-pprTermM1 y t@Term{} = panic "pprTermM1 - unreachable"
-pprTermM1 _ Suspension{bound_to=Nothing} = return$ char '_'
-pprTermM1 _ Suspension{mb_ty=Just ty, bound_to=Just n}
+ppr_termM1 Term{} = panic "ppr_termM1 - unreachable"
+ppr_termM1 Suspension{bound_to=Nothing} = return$ char '_'
+ppr_termM1 Suspension{mb_ty=Just ty, bound_to=Just n}
| Just _ <- splitFunTy_maybe ty = return$ ptext SLIT("<function>")
| otherwise = return$ parens$ ppr n <> text "::" <> ppr ty
+ppr_termM1 _ = panic "ppr_termM1"
--- Takes a list of custom printers with a explicit recursion knot and a term,
+pprNewtypeWrap y p NewtypeWrap{ty=ty, wrapped_term=t}
+ | Just (tc,_) <- splitNewTyConApp_maybe ty
+ , ASSERT(isNewTyCon tc) True
+ , Just new_dc <- maybeTyConSingleCon tc = do
+ real_term <- y 10 t
+ return$ cparen (p >= app_prec) (ppr new_dc <+> real_term)
+pprNewtypeWrap _ _ _ = panic "pprNewtypeWrap"
+
+-------------------------------------------------------
+-- Custom Term Pretty Printers
+-------------------------------------------------------
+
+-- We can want to customize the representation of a
+-- term depending on its type.
+-- However, note that custom printers have to work with
+-- type representations, instead of directly with types.
+-- We cannot use type classes here, unless we employ some
+-- typerep trickery (e.g. Weirich's RepLib tricks),
+-- which I didn't. Therefore, this code replicates a lot
+-- of what type classes provide for free.
+
+type CustomTermPrinter m = TermPrinterM m
+ -> [Precedence -> Term -> (m (Maybe SDoc))]
+
+-- | Takes a list of custom printers with a explicit recursion knot and a term,
-- and returns the output of the first succesful printer, or the default printer
-cPprTerm :: forall m. Monad m =>
- ((Int->Term->m SDoc)->[Int->Term->m (Maybe SDoc)]) -> Term -> m SDoc
-cPprTerm custom = go 0 where
- go prec t@Term{} = do
- let default_ prec t = Just `liftM` pprTermM go prec t
- mb_customDocs = [pp prec t | pp <- custom go ++ [default_]]
+cPprTerm :: Monad m => CustomTermPrinter m -> Term -> m SDoc
+cPprTerm printers_ = go 0 where
+ printers = printers_ go
+ go prec t | isTerm t || isNewtypeWrap t = do
+ let default_ = Just `liftM` pprTermM go prec t
+ mb_customDocs = [pp prec t | pp <- printers] ++ [default_]
Just doc <- firstJustM mb_customDocs
return$ cparen (prec>app_prec+1) doc
- go _ t = pprTermM1 go t
+ go _ t = pprTermM1 t
+
firstJustM (mb:mbs) = mb >>= maybe (firstJustM mbs) (return . Just)
firstJustM [] = return Nothing
-- Default set of custom printers. Note that the recursion knot is explicit
-cPprTermBase :: Monad m => (Int->Term-> m SDoc)->[Int->Term->m (Maybe SDoc)]
+cPprTermBase :: Monad m => CustomTermPrinter m
cPprTermBase y =
- [
- ifTerm isTupleTy (\_ -> liftM (parens . hcat . punctuate comma)
- . mapM (y (-1)) . subTerms)
- , ifTerm (\t -> isTyCon listTyCon t && subTerms t `lengthIs` 2)
- (\ p Term{subTerms=[h,t]} -> doList p h t)
- , ifTerm (isTyCon intTyCon) (coerceShow$ \(a::Int)->a)
- , ifTerm (isTyCon charTyCon) (coerceShow$ \(a::Char)->a)
--- , ifTerm (isTyCon wordTyCon) (coerceShow$ \(a::Word)->a)
- , ifTerm (isTyCon floatTyCon) (coerceShow$ \(a::Float)->a)
- , ifTerm (isTyCon doubleTyCon) (coerceShow$ \(a::Double)->a)
- , ifTerm isIntegerTy (coerceShow$ \(a::Integer)->a)
- ]
- where ifTerm pred f p t@Term{} | pred t = liftM Just (f p t)
- ifTerm _ _ _ _ = return Nothing
- isIntegerTy Term{ty=ty} = fromMaybe False $ do
+ [ ifTerm (isTupleTy.ty) (\_p -> liftM (parens . hcat . punctuate comma)
+ . mapM (y (-1))
+ . subTerms)
+ , ifTerm (\t -> isTyCon listTyCon (ty t) && subTerms t `lengthIs` 2)
+ (\ p Term{subTerms=[h,t]} -> doList p h t)
+ , ifTerm (isTyCon intTyCon . ty) (coerceShow$ \(a::Int)->a)
+ , ifTerm (isTyCon charTyCon . ty) (coerceShow$ \(a::Char)->a)
+ , ifTerm (isTyCon floatTyCon . ty) (coerceShow$ \(a::Float)->a)
+ , ifTerm (isTyCon doubleTyCon . ty) (coerceShow$ \(a::Double)->a)
+ , ifTerm (isIntegerTy . ty) (coerceShow$ \(a::Integer)->a)
+ ]
+ where ifTerm pred f prec t@Term{}
+ | pred t = Just `liftM` f prec t
+ ifTerm _ _ _ _ = return Nothing
+
+ isIntegerTy ty = fromMaybe False $ do
(tc,_) <- splitTyConApp_maybe ty
return (tyConName tc == integerTyConName)
- isTupleTy Term{ty=ty} = fromMaybe False $ do
+
+ isTupleTy ty = fromMaybe False $ do
(tc,_) <- splitTyConApp_maybe ty
return (tc `elem` (fst.unzip.elems) boxedTupleArr)
- isTyCon a_tc Term{ty=ty} = fromMaybe False $ do
+
+ isTyCon a_tc ty = fromMaybe False $ do
(tc,_) <- splitTyConApp_maybe ty
return (a_tc == tc)
- coerceShow f _ = return . text . show . f . unsafeCoerce# . val
- --TODO pprinting of list terms is not lazy
+
+ coerceShow f _p = return . text . show . f . unsafeCoerce# . val
+
+ --NOTE pprinting of list terms is not lazy
doList p h t = do
- let elems = h : getListTerms t
+ let elems = h : getListTerms t
isConsLast = termType(last elems) /= termType h
print_elems <- mapM (y cons_prec) elems
return$ if isConsLast
- then cparen (p >= cons_prec) . hsep . punctuate (space<>colon)
- $ print_elems
- else brackets (hcat$ punctuate comma print_elems)
+ then cparen (p >= cons_prec)
+ . pprDeeperList fsep
+ . punctuate (space<>colon)
+ $ print_elems
+ else brackets (pprDeeperList fcat$
+ punctuate comma print_elems)
where Just a /= Just b = not (a `coreEqType` b)
_ /= _ = True
getListTerms Term{subTerms=[h,t]} = h : getListTerms t
- getListTerms t@Term{subTerms=[]} = []
+ getListTerms Term{subTerms=[]} = []
getListTerms t@Suspension{} = [t]
getListTerms t = pprPanic "getListTerms" (ppr t)
runTR_maybe :: HscEnv -> TR a -> IO (Maybe a)
runTR_maybe hsc_env = fmap snd . initTc hsc_env HsSrcFile False iNTERACTIVE
+traceTR :: SDoc -> TR ()
+traceTR = liftTcM . traceTc
+
trIO :: IO a -> TR a
trIO = liftTcM . ioToTcRn
-- | Returns the instantiated type scheme ty', and the substitution sigma
-- such that sigma(ty') = ty
instScheme :: Type -> TR (TcType, TvSubst)
-instScheme ty | (tvs, rho) <- tcSplitForAllTys ty = liftTcM$ do
- (tvs',theta,ty') <- tcInstType (mapM tcInstTyVar) ty
+instScheme ty | (tvs, _rho) <- tcSplitForAllTys ty = liftTcM$ do
+ (tvs',_theta,ty') <- tcInstType (mapM tcInstTyVar) ty
return (ty', zipTopTvSubst tvs' (mkTyVarTys tvs))
-- Adds a constraint of the form t1 == t2
cvObtainTerm hsc_env bound force mb_ty hval = runTR hsc_env $ do
tv <- newVar argTypeKind
case mb_ty of
- Nothing -> go bound tv tv hval >>= zonkTerm
- Just ty | isMonomorphic ty -> go bound ty ty hval >>= zonkTerm
+ Nothing -> go bound tv tv hval
+ >>= zonkTerm
+ >>= return . expandNewtypes
+ Just ty | isMonomorphic ty -> go bound ty ty hval
+ >>= zonkTerm
+ >>= return . expandNewtypes
Just ty -> do
(ty',rev_subst) <- instScheme (sigmaType ty)
addConstraint tv ty'
term <- go bound tv tv hval >>= zonkTerm
--restore original Tyvars
- return$ mapTermType (substTy rev_subst) term
+ return$ expandNewtypes $ mapTermType (substTy rev_subst) term
where
go bound _ _ _ | seq bound False = undefined
- go 0 tv ty a = do
+ go 0 tv _ty a = do
clos <- trIO $ getClosureData a
return (Suspension (tipe clos) (Just tv) a Nothing)
go bound tv ty a = do
-- and showing the '_' is more useful.
t | isThunk t && force -> seq a $ go (pred bound) tv ty a
-- We always follow indirections
- Indirection _ -> go (pred bound) tv ty $! (ptrs clos ! 0)
+ Indirection _ -> go bound tv ty $! (ptrs clos ! 0)
-- The interesting case
Constr -> do
Right dcname <- dataConInfoPtrToName (infoPtr clos)
tipe_clos ->
return (Suspension tipe_clos (Just tv) a Nothing)
--- matchSubTypes dc ty | pprTrace "matchSubtypes" (ppr dc <+> ppr ty) False = undefined
matchSubTypes dc ty
| Just (_,ty_args) <- splitTyConApp_maybe (repType ty)
-- assumption: ^^^ looks through newtypes
| isPointed ty = ASSERT2(not(null pointed)
, ptext SLIT("reOrderTerms") $$
(ppr pointed $$ ppr unpointed))
- head pointed : reOrderTerms (tail pointed) unpointed tys
+ let (t:tt) = pointed in t : reOrderTerms tt unpointed tys
| otherwise = ASSERT2(not(null unpointed)
, ptext SLIT("reOrderTerms") $$
(ppr pointed $$ ppr unpointed))
- head unpointed : reOrderTerms pointed (tail unpointed) tys
+ let (t:tt) = unpointed in t : reOrderTerms pointed tt tys
+
+ expandNewtypes t@Term{ ty=ty, subTerms=tt }
+ | Just (tc, args) <- splitNewTyConApp_maybe ty
+ , isNewTyCon tc
+ , wrapped_type <- newTyConInstRhs tc args
+ , Just dc <- maybeTyConSingleCon tc
+ , t' <- expandNewtypes t{ ty = wrapped_type
+ , subTerms = map expandNewtypes tt }
+ = NewtypeWrap ty (Right dc) t'
+ | otherwise = t{ subTerms = map expandNewtypes tt }
+
+ expandNewtypes t = t
-- Fast, breadth-first Type reconstruction
-max_depth = 10 :: Int
-cvReconstructType :: HscEnv -> Bool -> Maybe Type -> HValue -> IO (Maybe Type)
-cvReconstructType hsc_env force mb_ty hval = runTR_maybe hsc_env $ do
+cvReconstructType :: HscEnv -> Int -> Maybe Type -> HValue -> IO (Maybe Type)
+cvReconstructType hsc_env max_depth mb_ty hval = runTR_maybe hsc_env $ do
tv <- newVar argTypeKind
case mb_ty of
Nothing -> do search (isMonomorphic `fmap` zonkTcType tv)
substTy rev_subst `fmap` zonkTcType tv
where
-- search :: m Bool -> ([a] -> [a] -> [a]) -> [a] -> m ()
- search stop expand l depth | Seq.null l = return ()
- search stop expand x 0 = fail$ "Failed to reconstruct a type after " ++
- show max_depth ++ " steps"
- search stop expand l d | x :< xx <- viewl l = unlessM stop $ do
- new <- expand x
- search stop expand (xx `mappend` Seq.fromList new) $! (pred d)
+ search _ _ _ 0 = traceTR (text "Failed to reconstruct a type after " <>
+ int max_depth <> text " steps")
+ search stop expand l d =
+ case viewl l of
+ EmptyL -> return ()
+ x :< xx -> unlessM stop $ do
+ new <- expand x
+ search stop expand (xx `mappend` Seq.fromList new) $! (pred d)
-- returns unification tasks,since we are going to want a breadth-first search
go :: Type -> HValue -> TR [(Type, HValue)]
case mb_dc of
Nothing-> do
-- TODO: Check this case
- vars <- replicateM (length$ elems$ ptrs clos)
- (newVar (liftedTypeKind))
- subTerms <- sequence [ appArr (go tv) (ptrs clos) i
- | (i, tv) <- zip [0..] vars]
forM [0..length (elems $ ptrs clos)] $ \i -> do
tv <- newVar liftedTypeKind
return$ appArr (\e->(tv,e)) (ptrs clos) i
return $ [ appArr (\e->(t,e)) (ptrs clos) i
| (i,t) <- drop extra_args $
zip [0..] (filter isPointed subTtypes)]
- otherwise -> return []
+ _ -> return []
-- This helper computes the difference between a base type t and the
-- improved rtti_t computed by RTTI
-- The main difference between RTTI types and their normal counterparts
-- is that the former are _not_ polymorphic, thus polymorphism must
- -- be stripped. Syntactically, forall's must be stripped
+ -- be stripped. Syntactically, forall's must be stripped.
+ -- We also remove predicates.
+computeRTTIsubst :: Type -> Type -> TvSubst
computeRTTIsubst ty rtti_ty =
+ case mb_subst of
+ Just subst -> subst
+ Nothing -> pprPanic "Failed to compute a RTTI substitution"
+ (ppr (ty, rtti_ty))
-- In addition, we strip newtypes too, since the reconstructed type might
-- not have recovered them all
- tcUnifyTys (const BindMe)
- [repType' $ dropForAlls$ ty]
- [repType' $ rtti_ty]
--- TODO stripping newtypes shouldn't be necessary, test
-
+ -- TODO stripping newtypes shouldn't be necessary, test
+ where mb_subst = tcUnifyTys (const BindMe)
+ [rttiView ty]
+ [rttiView rtti_ty]
-- Dealing with newtypes
{-
Note that it is very tricky to make this 'rewriting'
work with the unification implemented by TcM, where
substitutions are 'inlined'. The order in which
- constraints are unified is vital for this (or I am
- using TcM wrongly).
+ constraints are unified is vital for this.
+ This is a simple form of residuation, the technique of
+ delaying unification steps until enough information
+ is available.
-}
-congruenceNewtypes :: TcType -> TcType -> TcM (TcType,TcType)
+congruenceNewtypes :: TcType -> TcType -> TR (TcType,TcType)
congruenceNewtypes lhs rhs
-- TyVar lhs inductive case
| Just tv <- getTyVar_maybe lhs
= recoverTc (return (lhs,rhs)) $ do
Indirect ty_v <- readMetaTyVar tv
- (lhs1, rhs1) <- congruenceNewtypes ty_v rhs
+ (_lhs1, rhs1) <- congruenceNewtypes ty_v rhs
return (lhs, rhs1)
-- FunTy inductive case
| Just (l1,l2) <- splitFunTy_maybe lhs
(l1',r1') <- congruenceNewtypes l1 r1
return (mkFunTy l1' l2', mkFunTy r1' r2')
-- TyconApp Inductive case; this is the interesting bit.
- | Just (tycon_l, args_l) <- splitNewTyConApp_maybe lhs
- , Just (tycon_r, args_r) <- splitNewTyConApp_maybe rhs
+ | Just (tycon_l, _) <- splitNewTyConApp_maybe lhs
+ , Just (tycon_r, _) <- splitNewTyConApp_maybe rhs
, tycon_l /= tycon_r
- = return (lhs, upgrade tycon_l rhs)
+ = do rhs' <- upgrade tycon_l rhs
+ return (lhs, rhs')
| otherwise = return (lhs,rhs)
- where upgrade :: TyCon -> Type -> Type
+ where upgrade :: TyCon -> Type -> TR Type
upgrade new_tycon ty
- | not (isNewTyCon new_tycon) = ty
- | ty' <- mkTyConApp new_tycon (map mkTyVarTy $ tyConTyVars new_tycon)
- , Just subst <- tcUnifyTys (const BindMe) [ty] [repType ty']
- = substTy subst ty'
- -- assumes that reptype doesn't touch tyconApp args ^^^
+ | not (isNewTyCon new_tycon) = return ty
+ | otherwise = do
+ vars <- mapM (newVar . tyVarKind) (tyConTyVars new_tycon)
+ let ty' = mkTyConApp new_tycon vars
+ liftTcM (unifyType ty (repType ty'))
+ -- assumes that reptype doesn't ^^^^ touch tyconApp args
+ return ty'
--------------------------------------------------------------------------------
-- Semantically different to recoverM in TcRnMonad
-- recoverM retains the errors in the first action,
-- whereas recoverTc here does not
+recoverTc :: TcM a -> TcM a -> TcM a
recoverTc recover thing = do
(_,mb_res) <- tryTcErrs thing
case mb_res of
Nothing -> recover
Just res -> return res
+isMonomorphic :: Type -> Bool
isMonomorphic ty | (tvs, ty') <- splitForAllTys ty
= null tvs && (isEmptyVarSet . tyVarsOfType) ty'
mapMif :: Monad m => (a -> Bool) -> (a -> m a) -> [a] -> m [a]
mapMif pred f xx = sequence $ mapMif_ pred f xx
-mapMif_ pred f [] = []
-mapMif_ pred f (x:xx) = (if pred x then f x else return x) : mapMif_ pred f xx
+ where
+ mapMif_ _ _ [] = []
+ mapMif_ pred f (x:xx) = (if pred x then f x else return x) : mapMif_ pred f xx
+unlessM :: Monad m => m Bool -> m () -> m ()
unlessM condM acc = condM >>= \c -> unless c acc
-- Strict application of f at index i
+appArr :: Ix i => (e -> a) -> Array i e -> Int -> a
appArr f a@(Array _ _ _ ptrs#) i@(I# i#)
= ASSERT (i < length(elems a))
case indexArray# ptrs# i# of
zonkTcType ty >>= \ty' ->
return (Term ty' dc v tt)
,fSuspension = \ct ty v b -> fmapMMaybe zonkTcType ty >>= \ty ->
- return (Suspension ct ty v b)}
+ return (Suspension ct ty v b)
+ ,fNewtypeWrap= \ty dc t ->
+ return NewtypeWrap `ap` zonkTcType ty `ap` return dc `ap` t}
-- Is this defined elsewhere?
-- Generalize the type: find all free tyvars and wrap in the appropiate ForAll.
+sigmaType :: Type -> Type
sigmaType ty = mkForAllTys (varSetElems$ tyVarsOfType (dropForAlls ty)) ty
projects / ghc-hetmet.git / blobdiff