-{-# OPTIONS -Wall -fno-warn-name-shadowing #-}
-{-
+{-# OPTIONS -fno-warn-name-shadowing #-}
+{-
Preprocess a module to normalize it in the following ways:
(1) Saturate all constructor and primop applications.
+ (as well as external calls; this is probably already
+ guaranteed, but paranoia is good)
(2) Arrange that any non-trivial expression of unlifted kind ('#')
is turned into the scrutinee of a Case.
After these preprocessing steps, Core can be interpreted (or given an operational semantics)
module Language.Core.Prep where
+--import Debug.Trace
+
+import Control.Monad.State
import Data.Either
import Data.List
+import Data.Generics
+import qualified Data.Map as M
-import Language.Core.Prims
import Language.Core.Core
+import Language.Core.CoreUtils
import Language.Core.Env
import Language.Core.Check
+import Language.Core.Environments
+import Language.Core.Utils
prepModule :: Menv -> Module -> Module
prepModule globalEnv (Module mn tdefs vdefgs) =
- Module mn tdefs vdefgs'
+ Module mn tdefs (snd (evalState
+ (foldM prepTopVdefg (eempty,[]) vdefgs) initCounter))
where
+ (tcenv, cenv) = mkTypeEnvsNoChecking tdefs
- (_,vdefgs') = foldl prepTopVdefg (eempty,[]) vdefgs
-
- prepTopVdefg (venv,vdefgs) vdefg = (venv',vdefgs ++ [vdefg'])
- where (venv',vdefg') = prepVdefg (venv,eempty) vdefg
+ prepTopVdefg :: (Venv, [Vdefg]) -> Vdefg -> PrepM (Venv, [Vdefg])
+ prepTopVdefg (venv,vdefgs) vdefg = do
+ (venv',vdefg') <- prepVdefg (venv,eempty) vdefg
+ return (venv',vdefgs ++ [vdefg'])
- prepVdefg (env@(venv,_)) (Nonrec(Vdef((Nothing,x),t,e))) =
- (eextend venv (x,t), Nonrec(Vdef((Nothing,x),t,prepExp env e)))
- prepVdefg (env@(venv,_)) (Nonrec(Vdef(qx,t,e))) =
- (venv, Nonrec(Vdef(qx,t,prepExp env e)))
- prepVdefg (venv,tvenv) (Rec vdefs) =
- (venv',Rec [ Vdef(qx,t,prepExp (venv',tvenv) e) | Vdef(qx,t,e) <- vdefs])
- where venv' = foldl eextend venv [(x,t) | Vdef((Nothing,x),t,_) <- vdefs]
-
- prepExp _ (Var qv) = Var qv
- prepExp _ (Dcon qdc) = Dcon qdc
- prepExp _ (Lit l) = Lit l
+ prepVdefg (env@(venv,_)) (Nonrec(Vdef((Nothing,x),t,e))) = do
+ e' <- prepExp env e
+ return (eextend venv (x,t), Nonrec(Vdef((Nothing,x),t,e')))
+ prepVdefg (env@(venv,_)) (Nonrec(Vdef(qx,t,e))) = do
+ e' <- prepExp env e
+ return (venv, Nonrec(Vdef(qx,t,e')))
+ prepVdefg (venv,tvenv) (Rec vdefs) = do
+ vds' <- mapM (\ (Vdef (qx,t,e)) -> do
+ e' <- prepExp (venv',tvenv) e
+ return (Vdef (qx,t,e'))) vdefs
+ return (venv', Rec vds')
+ where venv' = foldl' eextend venv [(x,t) | Vdef((Nothing,x),t,_) <- vdefs]
+
+ prepExp :: (Venv, Tvenv) -> Exp -> PrepM Exp
+ prepExp _ (Var qv) = return $ Var qv
+ prepExp _ (Dcon qdc) = return $ Dcon qdc
+ prepExp _ (Lit l) = return $ Lit l
prepExp env e@(App _ _) = unwindApp env e []
prepExp env e@(Appt _ _) = unwindApp env e []
- prepExp (venv,tvenv) (Lam (Vb vb) e) = Lam (Vb vb) (prepExp (eextend venv vb,tvenv) e)
- prepExp (venv,tvenv) (Lam (Tb tb) e) = Lam (Tb tb) (prepExp (venv,eextend tvenv tb) e)
+ prepExp (venv,tvenv) (Lam (Vb vb) e) = do
+ e' <- prepExp (eextend venv vb,tvenv) e
+ return $ Lam (Vb vb) e'
+ prepExp (venv,tvenv) (Lam (Tb tb) e) = do
+ e' <- prepExp (venv,eextend tvenv tb) e
+ return $ Lam (Tb tb) e'
prepExp env@(venv,tvenv) (Let (Nonrec(Vdef((Nothing,x),t,b))) e)
- | (kindOfTy tvenv t `eqKind` Kunlifted && suspends b) =
+ | (kindOfTy tvenv t `eqKind` Kunlifted && suspends b) = do
-- There are two places where we call the typechecker, one of them
-- here.
-- We need to know the type of the let body in order to construct
-- a case expression.
-- need to extend the env with the let-bound var too!
- let eTy = typeOfExp (eextend venv (x, t), tvenv) e in
- Case (prepExp env b) (x,t)
- eTy
- [Adefault (prepExp (eextend venv (x,t),tvenv) e)]
- prepExp (venv,tvenv) (Let vdefg e) = Let vdefg' (prepExp (venv',tvenv) e)
- where (venv',vdefg') = prepVdefg (venv,tvenv) vdefg
- prepExp env@(venv,tvenv) (Case e vb t alts) = Case (prepExp env e) vb t (map (prepAlt (eextend venv vb,tvenv)) alts)
- prepExp env (Cast e t) = Cast (prepExp env e) t
- prepExp env (Note s e) = Note s (prepExp env e)
- prepExp _ (External s t) = External s t
-
- prepAlt (venv,tvenv) (Acon qdc tbs vbs e) = Acon qdc tbs vbs (prepExp (foldl eextend venv vbs,foldl eextend tvenv tbs) e)
- prepAlt env (Alit l e) = Alit l (prepExp env e)
- prepAlt env (Adefault e) = Adefault (prepExp env e)
-
-
+ scrut' <- prepExp env b
+ rhs' <- prepExp (eextend venv (x,t),tvenv) e
+ return $
+ let eTy = typeOfExp (eextend venv (x, t)) tvenv e in
+ Case scrut' (x,t) eTy [Adefault rhs']
+ prepExp (venv,tvenv) (Let vdefg e) = do
+ (venv',vdefg') <- prepVdefg (venv,tvenv) vdefg
+ rhs' <- prepExp (venv',tvenv) e
+ return $ Let vdefg' rhs'
+ prepExp env@(venv,tvenv) (Case e vb t alts) = do
+ e' <- prepExp env e
+ alts' <- mapM (prepAlt (eextend venv vb,tvenv)) alts
+ return $ Case e' vb t alts'
+ prepExp env (Cast e t) = do
+ e' <- prepExp env e
+ return $ Cast e' t
+ prepExp env (Note s e) = do
+ e' <- prepExp env e
+ return $ Note s e'
+ prepExp _ (External s t) = return $ External s t
+
+ prepAlt :: (Venv,Tvenv) -> Alt -> PrepM Alt
+ prepAlt (venv,tvenv) (Acon qdc tbs vbs e) = do
+ rhs' <- prepExp (foldl' eextend venv vbs,foldl' eextend tvenv tbs) e
+ return $ Acon qdc tbs vbs rhs'
+ prepAlt env (Alit l e) = (liftM (Alit l)) (prepExp env e)
+ prepAlt env (Adefault e) = (liftM Adefault) (prepExp env e)
+
+ unwindApp :: (Venv, Tvenv) -> Exp -> [Either Exp Ty] -> PrepM Exp
unwindApp env (App e1 e2) as = unwindApp env e1 (Left e2:as)
unwindApp env (Appt e t) as = unwindApp env e (Right t:as)
- unwindApp env (op@(Dcon qdc)) as =
+ unwindApp env (op@(Dcon qdc)) as = do
+ e' <- rewindApp env op as
-- possibly dubious to assume no type args
- etaExpand [] (drop n atys) (rewindApp env op as)
+ etaExpand [] (drop n atys) e'
where (tbs,atys0,_) = splitTy (qlookup cenv_ eempty qdc)
atys = map (substl (map fst tbs) ts) atys0
ts = [t | Right t <- as]
n = length [e | Left e <- as]
- unwindApp env (op@(Var(qv@(_,p)))) as | isPrimVar qv =
- etaExpand (snd (unzip extraTbs)) (drop n atys) (rewindApp env op as)
- where -- TODO: avoid copying code. these two cases are the same
-
- -- etaExpand needs to add the type arguments too! Bah!
- (tbs, atys0, _) = (maybe (error "unwindApp") splitTy (elookup (venv_ primEnv) p))
- n_args = length ts
- (appliedTbs, extraTbs) = (take n_args tbs, drop n_args tbs)
- atys = map (substl (map fst appliedTbs) ts) atys0
- ts = [t | Right t <- as]
- n = length [e | Left e <- as]
+ unwindApp env (op@(Var qv)) as | isPrimVar qv = do
+ e' <- rewindApp env op as
+ etaExpand [] [] e'
+ unwindApp env (op@(External _ t)) as = do
+ e' <- rewindApp env op as
+ etaExpand [] (drop n atys) e'
+ where (_,atys,_) = splitTy t
+ n = length as -- assumes all args are term args
unwindApp env op as = rewindApp env op as
- etaExpand :: [Kind] -> [Ty] -> Exp -> Exp
- etaExpand ks ts e =
+ etaExpand :: [Kind] -> [Ty] -> Exp -> PrepM Exp
+ etaExpand ks ts e = do
-- what a pain
- let tyArgs = [("$t_"++(show i),k) | (i, k) <- zip [(1::Integer)..] ks]
- termArgs = [ ('$':(show i),t) | (i,t) <- zip [(1::Integer)..] ts] in
+ tyvs <- replicateM (length ks) freshVar
+ termvs <- replicateM (length ts) freshVar
+ let tyArgs = zip tyvs ks
+ let termArgs = zip termvs ts
+ return $
foldr (\ (t1,k1) e -> Lam (Tb (t1,k1)) e)
(foldr (\ (v,t) e -> Lam (Vb (v,t)) e)
- (foldl (\ e (v,_) -> App e (Var (unqual v)))
- (foldl (\ e (tv,_) -> Appt e (Tvar tv))
+ (foldl' (\ e (v,_) -> App e (Var (unqual v)))
+ (foldl' (\ e (tv,_) -> Appt e (Tvar tv))
e tyArgs)
termArgs) termArgs)
tyArgs
- rewindApp _ e [] = e
- rewindApp env@(venv,tvenv) e1 (Left e2:as) | kindOfTy tvenv t `eqKind` Kunlifted && suspends e2 =
+ rewindApp :: (Venv, Tvenv) -> Exp -> [Either Exp Ty] -> PrepM Exp
+ rewindApp _ e [] = return e
+ rewindApp env@(venv,tvenv) e1 (Left e2:as) | kindOfTy tvenv t `eqKind` Kunlifted && suspends e2 = do
+ v <- freshVar
+ let venv' = eextend venv (v,t)
+ rhs <- rewindApp (venv', tvenv) (App e1 (Var (unqual v))) as
+ newScrut <- prepExp env e2
-- This is the other place where we call the typechecker.
- Case newScrut (v,t) (typeOfExp env' rhs) [Adefault rhs]
- where newScrut = prepExp env e2
- rhs = (rewindApp env' (App e1 (Var (unqual v))) as)
- -- note:
- -- e1 gets moved inside rhs. so if we pick a case
- -- var name (outside e1) equal to a name bound *inside*
- -- e1, the binding *inside* e1 will shadow "v"
- -- Which would be name capture!
- -- So, we pass the bound vars of e1 to freshVar along with
- -- the domain of the current env.
- v = freshVar (edomain venv `union` (boundVars e1))
- t = typeOfExp env e2
- env' = (eextend venv (v,t),tvenv)
- rewindApp env e1 (Left e2:as) = rewindApp env (App e1 (prepExp env e2)) as
+ return $ Case newScrut (v,t) (typeOfExp venv' tvenv rhs) [Adefault rhs]
+ where t = typeOfExp venv tvenv e2
+ rewindApp env e1 (Left e2:as) = do
+ e2' <- prepExp env e2
+ rewindApp env (App e1 e2') as
rewindApp env e (Right t:as) = rewindApp env (Appt e t) as
- freshVar vs = maximum ("":vs) ++ "x" -- one simple way!
-
- typeOfExp :: (Venv, Tvenv) -> Exp -> Ty
- typeOfExp = uncurry (checkExpr mn globalEnv tdefs)
+ typeOfExp :: Venv -> Tvenv -> Exp -> Ty
+ typeOfExp = checkExpr mn globalEnv tcenv cenv
kindOfTy :: Tvenv -> Ty -> Kind
- kindOfTy tvenv = checkType mn globalEnv tdefs tvenv
+ kindOfTy tvenv = checkType mn globalEnv tcenv tvenv
{- Return false for those expressions for which Interp.suspendExp builds a thunk. -}
suspends (Var _) = False
boundVarsAlt :: Alt -> [Var]
boundVarsAlt (Acon _ _ vbs e) = (map fst vbs) `union` (boundVars e)
boundVarsAlt (Alit _ e) = boundVars e
-boundVarsAlt (Adefault e) = boundVars e
\ No newline at end of file
+boundVarsAlt (Adefault e) = boundVars e
+
+substNewtys :: NtEnv -> Ty -> Ty
+substNewtys ntEnv = everywhere'Except (mkT go)
+ where go t | Just ((_,tc),args) <- splitTyConApp_maybe t =
+ case M.lookup tc ntEnv of
+ Just d -> -- trace ("applying newtype: " ++ show t) $
+ (snd (applyNewtype d args))
+ Nothing -> t
+ go t = t
+
+newtypeCoercion_maybe :: NtEnv -> Ty -> Maybe CoercionKind
+newtypeCoercion_maybe ntEnv t | Just ((_,tc),_) <- splitTyConApp_maybe t =
+ M.lookup tc ntEnv
+newtypeCoercion_maybe _ _ = Nothing
+
+mkTapp :: Ty -> [Ty] -> Ty
+mkTapp = foldl Tapp
+
+initCounter :: Int
+initCounter = 0
+
+type PrepM = State Int
+
+freshVar :: PrepM String
+freshVar = do
+ i <- get
+ put (i+1)
+ return $ ("zd" ++ show i)
projects / ghc-hetmet.git / blobdiff