isFullyEvaluated,
isPointed,
isFullyEvaluatedTerm,
+ mapTermType,
+ termTyVars,
-- unsafeDeepSeq,
+ cvReconstructType
) where
#include "HsVersions.h"
import DataCon
import Type
-import TcRnMonad ( TcM, initTcPrintErrors, ioToTcRn, recoverM, writeMutVar )
+import TcRnMonad ( TcM, initTcPrintErrors, ioToTcRn, recoverM
+ , writeMutVar )
import TcType
import TcMType
import TcUnify
import PrelNames
import TysWiredIn
-import Constants ( wORD_SIZE )
+import Constants
import Outputable
import Maybes
import Panic
import GHC.Arr ( Array(..) )
import GHC.Ptr ( Ptr(..), castPtr )
-import GHC.Exts
-import GHC.Int ( Int32(..), Int64(..) )
-import GHC.Word ( Word32(..), Word64(..) )
+import GHC.Exts
import Control.Monad
import Data.Maybe
import Data.Array.Base
import Data.List ( partition, nub )
-import Foreign.Storable
-
-import IO
+import Foreign
+import System.IO.Unsafe
---------------------------------------------
-- * A representation of semi evaluated Terms
, subTerms :: [Term] }
| Prim { ty :: Type
- , value :: String }
+ , value :: [Word] }
| Suspension { ctype :: ClosureType
, mb_ty :: Maybe Type
, infoPtr :: Ptr ()
, infoTable :: StgInfoTable
, ptrs :: Array Int HValue
- , nonPtrs :: ByteArray#
+ , nonPtrs :: [Word]
}
instance Outputable ClosureType where
let tipe = readCType (BCI.tipe itbl)
elems = BCI.ptrs itbl
ptrsList = Array 0 (fromIntegral$ elems) ptrs
- ptrsList `seq` return (Closure tipe (Ptr iptr) itbl ptrsList nptrs)
+ nptrs_data = [W# (indexWordArray# nptrs i)
+ | I# i <- [0.. fromIntegral (BCI.nptrs itbl)] ]
+ ptrsList `seq`
+ return (Closure tipe (Ptr iptr) itbl ptrsList nptrs_data)
readCType :: Integral a => a -> ClosureType
readCType i
unsafeDeepSeq :: a -> b -> b
unsafeDeepSeq = unsafeDeepSeq1 2
where unsafeDeepSeq1 0 a b = seq a $! b
- unsafeDeepSeq1 i a b -- 1st case avoids infinite loops for non reducible thunks
+ unsafeDeepSeq1 i a b -- 1st case avoids infinite loops for non reducible thunks
| not (isConstr tipe) = seq a $! unsafeDeepSeq1 (i-1) a b
-- | unsafePerformIO (isFullyEvaluated a) = b
| otherwise = case unsafePerformIO (getClosureData a) of
where tipe = unsafePerformIO (getClosureType a)
-}
isPointed :: Type -> Bool
-isPointed t | Just (t, _) <- splitTyConApp_maybe t = not$ isUnliftedTypeKind (tyConKind t)
+isPointed t | Just (t, _) <- splitTyConApp_maybe t
+ = not$ isUnliftedTypeKind (tyConKind t)
isPointed _ = True
-#define MKDECODER(offset,cons,builder) (offset, show$ cons (builder addr 0#))
-
-extractUnboxed :: [Type] -> ByteArray# -> [String]
-extractUnboxed tt ba = helper tt (byteArrayContents# ba)
- where helper :: [Type] -> Addr# -> [String]
- helper (t:tt) addr
- | Just ( tycon,_) <- splitTyConApp_maybe t
- = let (offset, txt) = decode tycon addr
- (I# word_offset) = offset*wORD_SIZE
- in txt : helper tt (plusAddr# addr word_offset)
- | otherwise
- = -- ["extractUnboxed.helper: Urk. I got a " ++ showSDoc (ppr t)]
- panic$ "extractUnboxed.helper: Urk. I got a " ++ showSDoc (ppr t)
- helper [] addr = []
- decode :: TyCon -> Addr# -> (Int, String)
- decode t addr
- | t == charPrimTyCon = MKDECODER(1,C#,indexCharOffAddr#)
- | t == intPrimTyCon = MKDECODER(1,I#,indexIntOffAddr#)
- | t == wordPrimTyCon = MKDECODER(1,W#,indexWordOffAddr#)
- | t == floatPrimTyCon = MKDECODER(1,F#,indexFloatOffAddr#)
- | t == doublePrimTyCon = MKDECODER(2,D#,indexDoubleOffAddr#)
- | t == int32PrimTyCon = MKDECODER(1,I32#,indexInt32OffAddr#)
- | t == word32PrimTyCon = MKDECODER(1,W32#,indexWord32OffAddr#)
- | t == int64PrimTyCon = MKDECODER(2,I64#,indexInt64OffAddr#)
- | t == word64PrimTyCon = MKDECODER(2,W64#,indexWord64OffAddr#)
- | t == addrPrimTyCon = MKDECODER(1,I#,(\x off-> addr2Int# (indexAddrOffAddr# x off))) --OPT Improve the presentation of addresses
- | t == stablePtrPrimTyCon = (1, "<stablePtr>")
- | t == stableNamePrimTyCon = (1, "<stableName>")
- | t == statePrimTyCon = (1, "<statethread>")
- | t == realWorldTyCon = (1, "<realworld>")
- | t == threadIdPrimTyCon = (1, "<ThreadId>")
- | t == weakPrimTyCon = (1, "<Weak>")
- | t == arrayPrimTyCon = (1,"<array>")
- | t == byteArrayPrimTyCon = (1,"<bytearray>")
- | t == mutableArrayPrimTyCon = (1, "<mutableArray>")
- | t == mutableByteArrayPrimTyCon = (1, "<mutableByteArray>")
- | t == mutVarPrimTyCon= (1, "<mutVar>")
- | t == mVarPrimTyCon = (1, "<mVar>")
- | t == tVarPrimTyCon = (1, "<tVar>")
- | otherwise = (1, showSDoc (char '<' <> ppr t <> char '>'))
- -- We cannot know the right offset in the otherwise case, so 1 is just a wild dangerous guess!
- -- TODO: Improve the offset handling in decode (make it machine dependant)
+extractUnboxed :: [Type] -> Closure -> [[Word]]
+extractUnboxed tt clos = go tt (nonPtrs clos)
+ where sizeofType t
+ | Just (tycon,_) <- splitTyConApp_maybe t
+ = ASSERT (isPrimTyCon tycon) sizeofTyCon tycon
+ | otherwise = pprPanic "Expected a TcTyCon" (ppr t)
+ go [] _ = []
+ go (t:tt) xx
+ | (x, rest) <- splitAt (sizeofType t `div` wORD_SIZE) xx
+ = x : go tt rest
+
+sizeofTyCon = sizeofPrimRep . tyConPrimRep
-----------------------------------
-- * Traversals for Terms
-----------------------------------
data TermFold a = TermFold { fTerm :: Type -> DataCon -> HValue -> [a] -> a
- , fPrim :: Type -> String -> a
- , fSuspension :: ClosureType -> Maybe Type -> HValue -> Maybe Name -> a
+ , fPrim :: Type -> [Word] -> a
+ , fSuspension :: ClosureType -> Maybe Type -> HValue
+ -> Maybe Name -> a
}
foldTerm :: TermFold a -> Term -> a
fSuspension = (((return.).).). Suspension
}
+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 }
+
+termTyVars = foldTerm TermFold {
+ fTerm = \ty _ _ tt ->
+ tyVarsOfType ty `plusVarEnv` concatVarEnv tt,
+ fSuspension = \_ mb_ty _ _ ->
+ maybe emptyVarEnv tyVarsOfType mb_ty,
+ fPrim = \ _ _ -> emptyVarEnv }
+ where concatVarEnv = foldr plusVarEnv emptyVarEnv
----------------------------------
-- Pretty printing of terms
----------------------------------
pprTerm _ t = pprTerm1 t
-pprTerm1 Prim{value=value} = text value
+pprTerm1 Prim{value=words, ty=ty} = text$ repPrim (tyConAppTyCon ty) words
pprTerm1 t@Term{} = pprTerm 0 t
pprTerm1 Suspension{bound_to=Nothing} = char '_' -- <> ppr ct <> char '_'
pprTerm1 Suspension{mb_ty=Just ty, bound_to=Just n}
| otherwise = parens$ ppr n <> text "::" <> ppr ty
-cPprTerm :: forall m. Monad m => ((Int->Term->m SDoc)->[Int->Term->m (Maybe SDoc)]) -> Term -> m SDoc
+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{subTerms=tt, dc=dc} = do
let mb_customDocs = map (($t) . ($prec)) (custom go) :: [m (Maybe SDoc)]
, ifTerm (isDC doubleDataCon) (coerceShow$ \(a::Double)->a)
, ifTerm isIntegerDC (coerceShow$ \(a::Integer)->a)
]
- where ifTerm pred f p t = if pred t then liftM Just (f p t) else return Nothing
+ where ifTerm pred f p t = if pred t then liftM Just (f p t)
+ else return Nothing
isIntegerDC Term{dc=dc} =
dataConName dc `elem` [ smallIntegerDataConName
, largeIntegerDataConName]
getListTerms t@Suspension{} = [t]
getListTerms t = pprPanic "getListTerms" (ppr t)
+repPrim :: TyCon -> [Word] -> String
+repPrim t = rep where
+ rep x
+ | t == charPrimTyCon = show (build x :: Char)
+ | t == intPrimTyCon = show (build x :: Int)
+ | t == wordPrimTyCon = show (build x :: Word)
+ | t == floatPrimTyCon = show (build x :: Float)
+ | t == doublePrimTyCon = show (build x :: Double)
+ | t == int32PrimTyCon = show (build x :: Int32)
+ | t == word32PrimTyCon = show (build x :: Word32)
+ | t == int64PrimTyCon = show (build x :: Int64)
+ | t == word64PrimTyCon = show (build x :: Word64)
+ | t == addrPrimTyCon = show (nullPtr `plusPtr` build x)
+ | t == stablePtrPrimTyCon = "<stablePtr>"
+ | t == stableNamePrimTyCon = "<stableName>"
+ | t == statePrimTyCon = "<statethread>"
+ | t == realWorldTyCon = "<realworld>"
+ | t == threadIdPrimTyCon = "<ThreadId>"
+ | t == weakPrimTyCon = "<Weak>"
+ | t == arrayPrimTyCon = "<array>"
+ | t == byteArrayPrimTyCon = "<bytearray>"
+ | t == mutableArrayPrimTyCon = "<mutableArray>"
+ | t == mutableByteArrayPrimTyCon = "<mutableByteArray>"
+ | t == mutVarPrimTyCon= "<mutVar>"
+ | t == mVarPrimTyCon = "<mVar>"
+ | t == tVarPrimTyCon = "<tVar>"
+ | otherwise = showSDoc (char '<' <> ppr t <> char '>')
+ where build ww = unsafePerformIO $ withArray ww (peek . castPtr)
+-- This ^^^ relies on the representation of Haskell heap values being
+-- the same as in a C array.
+
-----------------------------------
-- Type Reconstruction
-----------------------------------
+{-
+Type Reconstruction is type inference done on heap closures.
+The algorithm walks the heap generating a set of equations, which
+are solved with syntactic unification.
+A type reconstruction equation looks like:
+
+ <datacon reptype> = <actual heap contents>
+
+The full equation set is generated by traversing all the subterms, starting
+from a given term.
+
+The only difficult part is that newtypes are only found in the lhs of equations.
+Right hand sides are missing them. We can either (a) drop them from the lhs, or
+(b) reconstruct them in the rhs when possible.
+
+The function congruenceNewtypes takes a shot at (b)
+-}
-- The Type Reconstruction monad
type TR a = TcM a
-runTR :: HscEnv -> TR Term -> IO Term
+runTR :: HscEnv -> TR a -> IO a
runTR hsc_env c = do
- mb_term <- initTcPrintErrors hsc_env iNTERACTIVE (c >>= zonkTerm)
+ mb_term <- initTcPrintErrors hsc_env iNTERACTIVE c
case mb_term of
Nothing -> panic "Can't unify"
- Just term -> return term
+ Just x -> return x
trIO :: IO a -> TR a
trIO = liftTcM . ioToTcRn
+liftTcM = id
+
+newVar :: Kind -> TR TcTyVar
+newVar = liftTcM . newFlexiTyVar
+
+-- | 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
+ return (ty', zipTopTvSubst tvs' (mkTyVarTys tvs))
+
+-- Adds a constraint of the form t1 == t2
+-- t1 is expected to come from walking the heap
+-- t2 is expected to come from a datacon signature
+-- Before unification, congruenceNewtypes needs to
+-- do its magic.
addConstraint :: TcType -> TcType -> TR ()
addConstraint t1 t2 = congruenceNewtypes t1 t2 >>= uncurry unifyType
+
+
+-- Type & Term reconstruction
+cvObtainTerm :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term
+cvObtainTerm hsc_env force mb_ty hval = runTR hsc_env $ do
+ tv <- liftM mkTyVarTy (newVar argTypeKind)
+ case mb_ty of
+ Nothing -> go tv tv hval >>= zonkTerm
+ Just ty | isMonomorphic ty -> go ty ty hval >>= zonkTerm
+ Just ty -> do
+ (ty',rev_subst) <- instScheme (sigmaType ty)
+ addConstraint tv ty'
+ term <- go tv tv hval >>= zonkTerm
+ --restore original Tyvars
+ return$ mapTermType (substTy rev_subst) term
+ where
+ go tv ty a = do
+ let monomorphic = not(isTyVarTy tv)
+ -- This ^^^ is a convention. The ancestor tests for
+ -- monomorphism and passes a type instead of a tv
+ clos <- trIO $ getClosureData a
+ case tipe clos of
+-- Thunks we may want to force
+-- NB. this won't attempt to force a BLACKHOLE. Even with :force, we never
+-- force blackholes, because it would almost certainly result in deadlock,
+-- and showing the '_' is more useful.
+ t | isThunk t && force -> seq a $ go tv ty a
+-- We always follow indirections
+ Indirection _ -> go tv ty $! (ptrs clos ! 0)
+ -- The interesting case
+ Constr -> do
+ m_dc <- trIO$ tcRnRecoverDataCon hsc_env (infoPtr clos)
+ case m_dc of
+ Nothing -> panic "Can't find the DataCon for a term"
+ Just dc -> do
+ let extra_args = length(dataConRepArgTys dc) -
+ length(dataConOrigArgTys dc)
+ subTtypes = matchSubTypes dc ty
+ (subTtypesP, subTtypesNP) = partition isPointed subTtypes
+ subTermTvs <- sequence
+ [ if isMonomorphic t then return t
+ else (mkTyVarTy `fmap` newVar k)
+ | (t,k) <- zip subTtypesP (map typeKind subTtypesP)]
+ -- It is vital for newtype reconstruction that the unification step
+ -- is done right here, _before_ the subterms are RTTI reconstructed
+ when (not monomorphic) $ do
+ let myType = mkFunTys (reOrderTerms subTermTvs
+ subTtypesNP
+ subTtypes)
+ tv
+ (signatureType,_) <- instScheme(dataConRepType dc)
+ addConstraint myType signatureType
+ subTermsP <- sequence $ drop extra_args
+ -- ^^^ all extra arguments are pointed
+ [ appArr (go tv t) (ptrs clos) i
+ | (i,tv,t) <- zip3 [0..] subTermTvs subTtypesP]
+ let unboxeds = extractUnboxed subTtypesNP clos
+ subTermsNP = map (uncurry Prim) (zip subTtypesNP unboxeds)
+ subTerms = reOrderTerms subTermsP subTermsNP
+ (drop extra_args subTtypes)
+ return (Term tv dc a subTerms)
+-- The otherwise case: can be a Thunk,AP,PAP,etc.
+ otherwise ->
+ return (Suspension (tipe clos) (Just tv) a Nothing)
+
+ matchSubTypes dc ty
+ | Just (_,ty_args) <- splitTyConApp_maybe (repType ty)
+ , null (dataConExTyVars dc) --TODO case of extra existential tyvars
+ = dataConInstArgTys dc ty_args
+
+ | otherwise = dataConRepArgTys dc
+
+-- This is used to put together pointed and nonpointed subterms in the
+-- correct order.
+ reOrderTerms _ _ [] = []
+ reOrderTerms pointed unpointed (ty:tys)
+ | isPointed ty = ASSERT2(not(null pointed)
+ , ptext SLIT("reOrderTerms") $$
+ (ppr pointed $$ ppr unpointed))
+ head pointed : reOrderTerms (tail pointed) unpointed tys
+ | otherwise = ASSERT2(not(null unpointed)
+ , ptext SLIT("reOrderTerms") $$
+ (ppr pointed $$ ppr unpointed))
+ head unpointed : reOrderTerms pointed (tail unpointed) tys
+
+
+
+-- Fast, breadth-first Type reconstruction
+
+cvReconstructType :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Type
+cvReconstructType hsc_env force mb_ty hval = runTR hsc_env $ do
+ tv <- liftM mkTyVarTy (newVar argTypeKind)
+ case mb_ty of
+ Nothing -> do search (isMonomorphic `fmap` zonkTcType tv)
+ (uncurry go)
+ [(tv, hval)]
+ zonkTcType tv -- TODO untested!
+ Just ty | isMonomorphic ty -> return ty
+ Just ty -> do
+ (ty',rev_subst) <- instScheme (sigmaType ty)
+ addConstraint tv ty'
+ search (isMonomorphic `fmap` zonkTcType tv)
+ (uncurry go)
+ [(tv, hval)]
+ substTy rev_subst `fmap` zonkTcType tv
+ where
+-- search :: m Bool -> ([a] -> [a] -> [a]) -> [a] -> m ()
+ search stop expand [] = return ()
+ search stop expand (x:xx) = do new <- expand x
+ unlessM stop $ search stop expand (xx ++ new)
+
+ -- returns unification tasks,since we are going to want a breadth-first search
+ go :: Type -> HValue -> TR [(Type, HValue)]
+ go tv a = do
+ clos <- trIO $ getClosureData a
+ case tipe clos of
+ Indirection _ -> go tv $! (ptrs clos ! 0)
+ Constr -> do
+ m_dc <- trIO$ tcRnRecoverDataCon hsc_env (infoPtr clos)
+ case m_dc of
+ Nothing -> panic "Can't find the DataCon for a term"
+ Just dc -> do
+ let extra_args = length(dataConRepArgTys dc) -
+ length(dataConOrigArgTys dc)
+ subTtypes <- mapMif (not . isMonomorphic)
+ (\t -> mkTyVarTy `fmap` newVar (typeKind t))
+ (dataConRepArgTys dc)
+ -- It is vital for newtype reconstruction that the unification step
+ -- is done right here, _before_ the subterms are RTTI reconstructed
+ let myType = mkFunTys subTtypes tv
+ signatureType <- instScheme(dataConRepType dc)
+ addConstraint myType signatureType
+ return $ map (\(I# i#,t) -> case ptrs clos of
+ (Array _ _ ptrs#) -> case indexArray# ptrs# i# of
+ (# e #) -> (t,e))
+ (drop extra_args $ zip [0..] subTtypes)
+ otherwise -> return []
+
+
+-- Dealing with newtypes
{-
A parallel fold over two Type values,
compensating for missing newtypes on both sides.
let (tycon_l',args_l') = if isNewTyCon tycon_r && not(isNewTyCon tycon_l)
then (tycon_r, rewrite tycon_r lhs)
else (tycon_l, args_l)
- (tycon_r',args_r') = if rewriteRHS && isNewTyCon tycon_l && not(isNewTyCon tycon_r)
+ (tycon_r',args_r') = if rewriteRHS && isNewTyCon tycon_l &&
+ not(isNewTyCon tycon_r)
then (tycon_l, rewrite tycon_l rhs)
else (tycon_r, args_r)
- (args_l'', args_r'') <- unzip `liftM` zipWithM (go rewriteRHS) args_l' args_r'
+ (args_l'', args_r'') <- unzip `liftM` zipWithM (go rewriteRHS)
+ args_l'
+ args_r'
return (mkTyConApp tycon_l' args_l'', mkTyConApp tycon_r' args_r'')
| otherwise = return (lhs,rhs)
Just subst -> substTys subst (map mkTyVarTy tvs)
otherwise -> panic "congruenceNewtypes: Can't unify a newtype"
-newVar :: Kind -> TR TcTyVar
-newVar = liftTcM . newFlexiTyVar
-
-liftTcM = id
-
--- | 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
- return (ty', zipTopTvSubst tvs' (mkTyVarTys tvs))
-
-cvObtainTerm :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term
-cvObtainTerm hsc_env force mb_ty hval = runTR hsc_env $ do
- tv <- liftM mkTyVarTy (newVar argTypeKind)
- case mb_ty of
- Nothing -> go tv tv hval
- Just ty | isMonomorphic ty -> go ty ty hval
- Just ty -> do
- (ty',rev_subst) <- instScheme (sigmaType ty)
- addConstraint tv ty'
- term <- go tv tv hval
- --restore original Tyvars
- return$ flip foldTerm term idTermFold {
- fTerm = \ty dc hval tt -> Term (substTy rev_subst ty) dc hval tt,
- fSuspension = \ct mb_ty hval n ->
- Suspension ct (substTy rev_subst `fmap` mb_ty) hval n}
- where
- go tv ty a = do
- let monomorphic = not(isTyVarTy tv) -- This is a convention. The ancestor tests for
- -- monomorphism and passes a type instead of a tv
- clos <- trIO $ getClosureData a
- case tipe clos of
--- Thunks we may want to force
- t | isThunk t && force -> seq a $ go tv ty a
--- We always follow indirections
- Indirection _ -> go tv ty $! (ptrs clos ! 0)
- -- The interesting case
- Constr -> do
- m_dc <- trIO$ tcRnRecoverDataCon hsc_env (infoPtr clos)
- case m_dc of
- Nothing -> panic "Can't find the DataCon for a term"
- Just dc -> do
- let extra_args = length(dataConRepArgTys dc) - length(dataConOrigArgTys dc)
- subTtypes = matchSubTypes dc ty
- (subTtypesP, subTtypesNP) = partition isPointed subTtypes
- subTermTvs <- sequence
- [ if isMonomorphic t then return t else (mkTyVarTy `fmap` newVar k)
- | (t,k) <- zip subTtypesP (map typeKind subTtypesP)]
- -- It is vital for newtype reconstruction that the unification step is done
- -- right here, _before_ the subterms are RTTI reconstructed.
- when (not monomorphic) $ do
- let myType = mkFunTys (reOrderTerms subTermTvs subTtypesNP subTtypes) tv
- instScheme(dataConRepType dc) >>= addConstraint myType . fst
- subTermsP <- sequence $ drop extra_args -- all extra arguments are pointed
- [ appArr (go tv t) (ptrs clos) i
- | (i,tv,t) <- zip3 [0..] subTermTvs subTtypesP]
- let unboxeds = extractUnboxed subTtypesNP (nonPtrs clos)
- subTermsNP = map (uncurry Prim) (zip subTtypesNP unboxeds)
- subTerms = reOrderTerms subTermsP subTermsNP (drop extra_args subTtypes)
- return (Term tv dc a subTerms)
--- The otherwise case: can be a Thunk,AP,PAP,etc.
- otherwise ->
- return (Suspension (tipe clos) (Just tv) a Nothing)
--- Access the array of pointers and recurse down. Needs to be done with
--- care of no introducing a thunk! or go will fail to do its job
- appArr f arr (I# i#) = case arr of
- (Array _ _ ptrs#) -> case indexArray# ptrs# i# of
- (# e #) -> f e
+--------------------------------------------------------------------------------
- matchSubTypes dc ty
- | Just (_,ty_args) <- splitTyConApp_maybe (repType ty)
- , null (dataConExTyVars dc) --TODO Handle the case of extra existential tyvars
- = dataConInstArgTys dc ty_args
+isMonomorphic ty | (tvs, ty') <- splitForAllTys ty
+ = null tvs && (isEmptyVarSet . tyVarsOfType) ty'
- | otherwise = dataConRepArgTys dc
+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
--- This is used to put together pointed and nonpointed subterms in the
--- correct order.
- reOrderTerms _ _ [] = []
- reOrderTerms pointed unpointed (ty:tys)
- | isPointed ty = ASSERT2(not(null pointed)
- , ptext SLIT("reOrderTerms") $$ (ppr pointed $$ ppr unpointed))
- head pointed : reOrderTerms (tail pointed) unpointed tys
- | otherwise = ASSERT2(not(null unpointed)
- , ptext SLIT("reOrderTerms") $$ (ppr pointed $$ ppr unpointed))
- head unpointed : reOrderTerms pointed (tail unpointed) tys
+unlessM condM acc = condM >>= \c -> unless c acc
-isMonomorphic ty | isForAllTy ty = False
-isMonomorphic ty = (isEmptyVarSet . tyVarsOfType) ty
+-- Strict application of f at index i
+appArr f (Array _ _ ptrs#) (I# i#) = case indexArray# ptrs# i# of
+ (# e #) -> f e
zonkTerm :: Term -> TcM Term
zonkTerm = foldTerm idTermFoldM {
-- Generalize the type: find all free tyvars and wrap in the appropiate ForAll.
sigmaType ty = mkForAllTys (varSetElems$ tyVarsOfType (dropForAlls ty)) ty
-{-
-Example of Type Reconstruction
---------------------------------
-Suppose we have an existential type such as
-
-data Opaque = forall a. Opaque a
-
-And we have a term built as:
-
-t = Opaque (map Just [[1,1],[2,2]])
-
-The type of t as far as the typechecker goes is t :: Opaque
-If we seq the head of t, we obtain:
-
-t - O (_1::a)
-
-seq _1 ()
-
-t - O ( (_3::b) : (_4::[b]) )
-
-seq _3 ()
-
-t - O ( (Just (_5::c)) : (_4::[b]) )
-
-At this point, we know that b = (Maybe c)
-
-seq _5 ()
-t - O ( (Just ((_6::d) : (_7::[d]) )) : (_4::[b]) )
-
-At this point, we know that c = [d]
-
-seq _6 ()
-
-t - O ( (Just (1 : (_7::[d]) )) : (_4::[b]) )
-
-At this point, we know that d = Integer
-
-The fully reconstructed expressions, with propagation, would be:
-
-t - O ( (Just (_5::c)) : (_4::[Maybe c]) )
-t - O ( (Just ((_6::d) : (_7::[d]) )) : (_4::[Maybe [d]]) )
-t - O ( (Just (1 : (_7::[Integer]) )) : (_4::[Maybe [Integer]]) )
-
-
-For reference, the type of the thing inside the opaque is
-map Just [[1,1],[2,2]] :: [Maybe [Integer]]
-
-NOTE: (Num t) contexts have been manually replaced by Integer for clarity
--}
projects / ghc-hetmet.git / blobdiff