lhc-0.6.20090126: src/FrontEnd/Tc/Main.hs
module FrontEnd.Tc.Main (tiExpr, tiProgram, makeProgram, isTypePlaceholder ) where
import Control.Monad.Writer
import Data.Graph(stronglyConnComp, SCC(..))
import IO(hFlush,stdout)
import List
import qualified Data.Map as Map
import qualified Data.Set as Set
import qualified Text.PrettyPrint.ANSI.Leijen as P
import Control.Monad.Reader
import FrontEnd.DeclsDepends(getDeclDeps)
import FrontEnd.Diagnostic
import Doc.DocLike
import Doc.PPrint as PPrint
import FrontEnd.Desugar(doToExp)
import FrontEnd.KindInfer
import FrontEnd.SrcLoc
import FrontEnd.Tc.Class
import FrontEnd.Tc.Monad hiding(listenPreds)
import FrontEnd.Tc.Type
import FrontEnd.Tc.Kind
import FrontEnd.Tc.Unify
import FrontEnd.Utils(getDeclName)
import GenUtil
import FrontEnd.HsPretty
import FrontEnd.HsSyn
import Name.Name
import Name.Names
import Name.VConsts
import Options
import Support.FreeVars
import qualified FlagDump as FD
import qualified FlagOpts as FO
listenPreds = listenSolvePreds
type Expl = (Sigma, HsDecl)
-- TODO: this is different than the "Typing Haskell in Haskell" paper
-- we do not further sub-divide the implicitly typed declarations in
-- a binding group.
type BindGroup = ([Expl], [Either HsDecl [HsDecl]])
tcKnownApp e coerce vname as typ = do
sc <- lookupName vname
let (_,_,rt) = fromType sc
-- fall through if the type isn't arrowy enough (will produce type error)
if (length . fst $ fromTArrow rt) < length as then tcApps' e as typ else do
(ts,rt) <- freshInstance Sigma sc
e' <- if coerce then doCoerce (ctAp ts) e else return e
--addCoerce nname (ctAp ts)
let f (TArrow x y) (a:as) = do
a <- tcExprPoly a x
y <- evalType y
(as,fc) <- f y as
return (a:as,fc)
f lt [] = do
fc <- lt `subsumes` typ
return ([],fc)
(nas,CTId) <- f rt as
return (e',nas)
tcApps e@(HsVar v) as typ = do
let vname = toName Val v
--let nname = toName Val n
when (dump FD.BoxySteps) $ liftIO $ putStrLn $ "tcApps: " ++ (show vname)
rc <- asks tcRecursiveCalls
-- fall through if this is a recursive call to oneself
if (vname `Set.member` rc) then tcApps' e as typ else do
tcKnownApp e True vname as typ
tcApps e@(HsAsPat n (HsCon v)) as typ = do
let vname = toName DataConstructor v
let nname = toName Val n
when (dump FD.BoxySteps) $ liftIO $ putStrLn $ "tcApps: " ++ (show nname ++ "@" ++ show vname)
addToCollectedEnv (Map.singleton (toName Val n) typ)
tcKnownApp e False vname as typ
tcApps e as typ = tcApps' e as typ
-- the fall through case
tcApps' e as typ = do
bs <- sequence [ newBox kindArg | _ <- as ]
e' <- tcExpr e (foldr fn typ bs)
as' <- sequence [ tcExprPoly a r | r <- bs | a <- as ]
return (e',as')
tcApp e1 e2 typ = do
(e1,[e2]) <- tcApps e1 [e2] typ
return (e1,e2)
tiExprPoly,tcExprPoly :: HsExp -> Type -> Tc HsExp
tcExprPoly e t = do
t <- evalType t
tiExprPoly e t
tiExprPoly e t@TMetaVar {} = tcExpr e t -- GEN2
tiExprPoly e t = do -- GEN1
(ts,_,t) <- skolomize t
e <- tcExpr e t
doCoerce (ctAbs ts) e
doCoerce :: CoerceTerm -> HsExp -> Tc HsExp
doCoerce CTId e = return e
doCoerce ct e = do
(e',n) <- wrapInAsPat e
addCoerce n ct
return e'
wrapInAsPat :: HsExp -> Tc (HsExp,Name)
wrapInAsPat e = do
n <- newHsVar "As"
return (HsAsPat (nameName n) e, n)
newHsVar ns = do
nn <- newUniq
return $ toName Val (ns ++ "@",show nn)
isTypePlaceholder :: HsName -> Bool
isTypePlaceholder (Qual (Module "Wild@") _) = True
isTypePlaceholder (Qual (Module "As@") _) = True
isTypePlaceholder _ = False
tiExpr,tcExpr :: HsExp -> Type -> Tc HsExp
tcExpr e t = do
t <- evalType t
e <- tiExpr e t
--(_,False,_) <- unbox t
return e
tiExpr (HsVar v) typ = do
sc <- lookupName (toName Val v)
f <- sc `subsumes` typ
rc <- asks tcRecursiveCalls
if (toName Val v `Set.member` rc) then do
(e',n) <- wrapInAsPat (HsVar v)
tell mempty { outKnots = [(n,toName Val v)] }
return e'
else do
doCoerce f (HsVar v)
tiExpr (HsCase e alts) typ = withContext (simpleMsg $ "in the case expression\n case " ++ show e ++ " of ...") $ do
scrutinee <- newBox kindFunRet
e' <- tcExpr e scrutinee
alts' <- mapM (tcAlt scrutinee typ) alts
(ne,ap) <- wrapInAsPat (HsCase e' alts')
addToCollectedEnv (Map.singleton ap typ)
return ne
tiExpr (HsCon conName) typ = do
sc <- lookupName (toName DataConstructor conName)
sc `subsumes` typ
return (HsCon conName)
tiExpr (HsLit l@(HsIntPrim _)) typ = do
unBox typ
ty <- evalType typ
case ty of
TCon (Tycon n kh) | kh == kindHash -> return ()
_ -> ty `boxyMatch` (TCon (Tycon tc_Bits32 kindHash))
(ne,n) <- wrapInAsPat (HsLit l)
addToCollectedEnv (Map.singleton n ty)
return ne
tiExpr (HsLit l@(HsInt _)) typ = do
t <- tiLit l
t `subsumes` typ
(ne,n) <- wrapInAsPat (HsLit l)
addToCollectedEnv (Map.singleton n typ)
return ne
tiExpr err@HsError {} typ = do
unBox typ
(ne,n) <- wrapInAsPat err
addToCollectedEnv (Map.singleton n typ)
return ne
tiExpr (HsLit l) typ = do
t <- tiLit l
t `subsumes` typ
return (HsLit l)
tiExpr (HsAsPat n e) typ = do
e <- tcExpr e typ
--typ <- flattenType typ
addToCollectedEnv (Map.singleton (toName Val n) typ)
return (HsAsPat n e)
-- comb LET-S and VAR
tiExpr expr@(HsExpTypeSig sloc e qt) typ = withContext (locMsg sloc "in the annotated expression" $ render $ ppHsExp expr) $ do
kt <- getKindEnv
s <- hsQualTypeToSigma kt qt
s `subsumes` typ
e' <- tcExpr e typ
return (HsExpTypeSig sloc e' qt)
tiExpr (HsLeftSection e1 e2) typ = do
(e1,e2) <- tcApp e1 e2 typ
return (HsLeftSection e1 e2)
-- I know this looks weird but it appears to be correct
-- e1 :: b
-- e2 :: a -> b -> c
-- e1 e2 :: a -> c
-- (: []) \x -> x : [] `fn`
tiExpr (HsRightSection e1 e2) typ = do
arg <- newBox kindArg
arg2 <- newBox kindArg
ret <- newBox kindFunRet
e1 <- tcExpr e1 arg2
e2 <- tcExpr e2 (arg `fn` (arg2 `fn` ret))
(arg `fn` ret) `subsumes` typ
return (HsRightSection e1 e2)
tiExpr expr@HsApp {} typ = withContext (makeMsg "in the application" $ render $ ppHsExp $ backToApp h as) $ do
(h,as) <- tcApps h as typ
return $ backToApp h as
where
backToApp h as = foldl HsApp h as
(h,as) = fromHsApp expr
fromHsApp t = f t [] where
f (HsApp a b) rs = f a (b:rs)
f t rs = (t,rs)
tiExpr expr@(HsInfixApp e1 e2 e3) typ = withContext (makeMsg "in the infix application" $ render $ ppHsExp expr) $ do
(e2',[e1',e3']) <- tcApps e2 [e1,e3] typ
return (HsInfixApp e1' e2' e3')
-- we need to fix the type to to be in the class
-- cNum, just for cases such as:
-- foo = \x -> -x
tiExpr expr@(HsNegApp e) typ = withContext (makeMsg "in the negative expression" $ render $ ppHsExp expr) $ do
e <- tcExpr e typ
addPreds [IsIn class_Num typ]
return (HsNegApp e)
-- ABS1
tiExpr expr@(HsLambda sloc ps e) typ = withContext (locSimple sloc $ "in the lambda expression\n \\" ++ show (pprint ps:: P.Doc) ++ " -> ...") $ do
let lam (p:ps) e (TMetaVar mv) rs = do -- ABS2
withMetaVars mv [kindArg,kindFunRet] (\ [a,b] -> a `fn` b) $ \ [a,b] -> lam (p:ps) e (a `fn` b) rs
lam (p:ps) e (TArrow s1' s2') rs = do -- ABS1
--box <- newBox Star
--s1' `boxyMatch` box
(p',env) <- tcPat p s1'
localEnv env $ do
s2' <- evalType s2'
lamPoly ps e s2' (p':rs) -- TODO poly
lam (p:ps) e t@(TAp (TAp (TMetaVar mv) s1') s2') rs = do
boxyMatch (TMetaVar mv) tArrow
(p',env) <- tcPat p s1'
localEnv env $ do
s2' <- evalType s2'
lamPoly ps e s2' (p':rs) -- TODO poly
lam [] e typ rs = do
e' <- tcExpr e typ
return (HsLambda sloc (reverse rs) e')
lam _ _ t _ = do
t <- flattenType t
fail $ "expected a -> b, found: " ++ prettyPrintType t
lamPoly ps e s rs = do
(ts,_,s) <- skolomize s
e <- lam ps e s rs
doCoerce (ctAbs ts) e
lam ps e typ []
tiExpr (HsIf e e1 e2) typ = withContext (simpleMsg $ "in the if expression\n if " ++ show e ++ "...") $ do
e <- tcExpr e tBool
e1 <- tcExpr e1 typ
e2 <- tcExpr e2 typ
return (HsIf e e1 e2)
tiExpr tuple@(HsTuple exps@(_:_)) typ = withContext (makeMsg "in the tuple" $ render $ ppHsExp tuple) $ do
(_,exps') <- tcApps (HsCon (toTuple (length exps))) exps typ
return (HsTuple exps')
tiExpr tuple@(HsUnboxedTuple exps) typ = withContext (makeMsg "in the unboxed tuple" $ render $ ppHsExp tuple) $ do
(_,exps') <- tcApps (HsCon (nameName $ unboxedNameTuple DataConstructor (length exps))) exps typ
return (HsUnboxedTuple exps')
-- special case for the empty list
tiExpr (HsList []) (TAp c v) | c == tList = do
unBox v
return (HsList [])
-- special case for the empty list
tiExpr (HsList []) typ = do
v <- newVar kindStar
let lt = TForAll [v] ([] :=> TAp tList (TVar v))
lt `subsumes` typ
return (HsList [])
-- non empty list
tiExpr expr@(HsList exps@(_:_)) (TAp tList' v) | tList == tList' = withContext (makeMsg "in the list " $ render $ ppHsExp expr) $ do
exps' <- mapM (`tcExpr` v) exps
return (HsList exps')
-- non empty list
tiExpr expr@(HsList exps@(_:_)) typ = withContext (makeMsg "in the list " $ render $ ppHsExp expr) $ do
v <- newBox kindStar
exps' <- mapM (`tcExpr` v) exps
(TAp tList v) `subsumes` typ
return (HsList exps')
tiExpr (HsParen e) typ = tcExpr e typ
tiExpr (HsDo stmts) typ = withContext (simpleMsg "in a do expression") $ do
newExp <- doToExp stmts
tcExpr newExp typ
tiExpr expr@(HsLet decls e) typ = withContext (makeMsg "in the let binding" $ render $ ppHsExp expr) $ do
sigEnv <- getSigEnv
let bgs = getFunDeclsBg sigEnv decls
f (bg:bgs) rs = do
(ds,env) <- tcBindGroup bg
localEnv env $ f bgs (ds ++ rs)
f [] rs = do
e' <- tcExpr e typ
return (HsLet rs e')
f bgs []
tiExpr e typ = fail $ "tiExpr: not implemented for: " ++ show (e,typ)
tcWheres :: [HsDecl] -> Tc ([HsDecl],TypeEnv)
tcWheres decls = do
sigEnv <- getSigEnv
let bgs = getFunDeclsBg sigEnv decls
f (bg:bgs) rs cenv = do
(ds,env) <- tcBindGroup bg
localEnv env $ f bgs (ds ++ rs) (env `mappend` cenv)
f [] rs cenv = return (rs,cenv)
f bgs [] mempty
-----------------------------------------------------------------------------
-- type check implicitly typed bindings
tcAlt :: Sigma -> Sigma -> HsAlt -> Tc HsAlt
tcAlt scrutinee typ alt@(HsAlt sloc pat gAlts wheres) = withContext (locMsg sloc "in the alternative" $ render $ ppHsAlt alt) $ do
scrutinee <- evalType scrutinee
(pat',env) <- tcPat pat scrutinee
localEnv env $ do
(wheres', env) <- tcWheres wheres
localEnv env $ case gAlts of
HsUnGuardedRhs e -> do
e' <- tcExpr e typ
return (HsAlt sloc pat' (HsUnGuardedRhs e') wheres')
HsGuardedRhss as -> do
gas <- mapM (tcGuardedAlt typ) as
return (HsAlt sloc pat' (HsGuardedRhss gas) wheres')
tcGuardedAlt typ gAlt@(HsGuardedRhs sloc eGuard e) = withContext (locMsg sloc "in the guarded alternative" $ render $ ppGAlt gAlt) $ do
typ <- evalType typ
g' <- tcExpr eGuard tBool
e' <- tcExpr e typ
return (HsGuardedRhs sloc g' e')
tcGuardedRhs typ gAlt@(HsGuardedRhs sloc eGuard e) = withContext (locMsg sloc "in the guarded alternative" $ render $ ppHsGuardedRhs gAlt) $ do
typ <- evalType typ
g' <- tcExpr eGuard tBool
e' <- tcExpr e typ
return (HsGuardedRhs sloc g' e')
-- Typing Patterns
tiPat,tcPat :: HsPat -> Type -> Tc (HsPat, Map.Map Name Sigma)
tcPat p typ = withContext (makeMsg "in the pattern: " $ render $ ppHsPat p) $ do
typ <- evalType typ
tiPat p typ
tiPat (HsPVar i) typ = do
--v <- newMetaVar Tau Star
--v `boxyMatch` typ
--typ `subsumes` v
typ' <- unBox typ
addToCollectedEnv (Map.singleton (toName Val i) typ')
return (HsPVar i, Map.singleton (toName Val i) typ')
tiPat pl@(HsPLit HsChar {}) typ = boxyMatch tChar typ >> return (pl,mempty)
tiPat pl@(HsPLit HsString {}) typ = boxyMatch tString typ >> return (pl,mempty)
tiPat pl@(HsPLit HsInt {}) typ = do
unBox typ
addPreds [IsIn class_Num typ]
return (pl,mempty)
tiPat pl@(HsPLit HsIntPrim {}) typ = do
unBox typ
ty <- evalType typ
case ty of
TCon (Tycon n kh) | kh == kindHash -> return ()
_ -> ty `boxyMatch` (TCon (Tycon tc_Int__ kindHash))
return (pl,mempty)
tiPat pl@(HsPLit HsFrac {}) typ = do
unBox typ
addPreds [IsIn class_Fractional typ]
return (pl,mempty)
{-
tiPat (HsPLit l) typ = do
t <- tiLit l
typ `subsumes` t -- `boxyMatch` typ
return (HsPLit l,Map.empty)
-}
-- this is for negative literals only
-- so the pat must be a literal
-- it is safe not to make any predicates about
-- the pat, since the type checking of the literal
-- will do this for us
tiPat (HsPNeg (HsPLit (HsInt i))) typ = tiPat (HsPLit $ HsInt (negate i)) typ
tiPat (HsPNeg (HsPLit (HsFrac i))) typ = tiPat (HsPLit $ HsFrac (negate i)) typ
tiPat (HsPNeg (HsPLit (HsIntPrim i))) typ = tiPat (HsPLit $ HsIntPrim (negate i)) typ
tiPat (HsPNeg (HsPLit (HsFloatPrim i))) typ = tiPat (HsPLit $ HsFloatPrim (negate i)) typ
tiPat (HsPNeg (HsPLit (HsDoublePrim i))) typ = tiPat (HsPLit $ HsDoublePrim (negate i)) typ
tiPat (HsPNeg pat) typ = fail $ "non-literal negative patterns are not allowed"
--tiPat (HsPNeg pat) typ = tiPat pat typ
tiPat (HsPIrrPat (Located l p)) typ = do
(p,ns) <- tiPat p typ
return (HsPIrrPat (Located l p),ns)
tiPat (HsPParen p) typ = tiPat p typ
-- TODO check that constructors are saturated
tiPat (HsPApp conName pats) typ = do
s <- lookupName (toName DataConstructor conName)
nn <- deconstructorInstantiate s
let f (p:pats) (a `TArrow` rs) (ps,env) = do
(np,res) <- tiPat p a
f pats rs (np:ps,env `mappend` res)
f (p:pats) rs _ = do
fail $ "constructor applied to too many arguments:" <+> show p <+> prettyPrintType rs
f [] (_ `TArrow` _) _ = do
fail "constructor not applied to enough arguments"
f [] rs (ps,env) = do
rs `subsumes` typ
unBox typ
return (HsPApp conName (reverse ps), env)
f pats nn mempty
--bs <- sequence [ newBox Star | _ <- pats ]
--s `subsumes` (foldr fn typ bs)
--pats' <- sequence [ tcPat a r | r <- bs | a <- pats ]
--return (HsPApp conName (fsts pats'), mconcat (snds pats'))
tiPat pl@(HsPList []) (TAp t v) | t == tList = do
unBox v
return (delistPats [],mempty)
tiPat pl@(HsPList []) typ = do
v <- newBox kindStar
--typ `subsumes` TAp tList v
typ `boxyMatch` TAp tList v
return (delistPats [],mempty)
tiPat (HsPList pats@(_:_)) (TAp t v) | t == tList = do
--v <- newBox kindStar
--TAp tList v `boxyMatch` typ
--typ `subsumes` TAp tList v
ps <- mapM (`tcPat` v) pats
return (delistPats (fsts ps), mconcat (snds ps))
tiPat (HsPList pats@(_:_)) typ = do
v <- newBox kindStar
--TAp tList v `boxyMatch` typ
ps <- mapM (`tcPat` v) pats
typ `boxyMatch` TAp tList v
return (delistPats (fsts ps), mconcat (snds ps))
tiPat HsPWildCard typ = do
n <- newHsVar "Wild"
typ' <- unBox typ
addToCollectedEnv (Map.singleton n typ')
return (HsPVar (nameName n), Map.singleton n typ')
tiPat (HsPAsPat i pat) typ = do
(pat',env) <- tcPat pat typ
addToCollectedEnv (Map.singleton (toName Val i) typ)
return (HsPAsPat i pat', Map.insert (toName Val i) typ env)
tiPat (HsPInfixApp pLeft conName pRight) typ = tiPat (HsPApp conName [pLeft,pRight]) typ
tiPat (HsPUnboxedTuple ps) typ = tiPat (HsPApp (nameName $ unboxedNameTuple DataConstructor (length ps)) ps) typ
tiPat tuple@(HsPTuple pats) typ = tiPat (HsPApp (toTuple (length pats)) pats) typ
tiPat (HsPTypeSig _ pat qt) typ = do
kt <- getKindEnv
s <- hsQualTypeToSigma kt qt
s `boxyMatch` typ
p <- tcPat pat typ
return p
tiPat p _ = error $ "tiPat: " ++ show p
delistPats ps = pl ps where
pl [] = HsPApp (nameName $ dc_EmptyList) []
pl (p:xs) = HsPApp (nameName $ dc_Cons) [p, pl xs]
tcBindGroup :: BindGroup -> Tc ([HsDecl], TypeEnv)
tcBindGroup (es, is) = do
let env1 = Map.fromList [(getDeclName decl, sc) | (sc,decl) <- es ]
localEnv env1 $ do
(impls, implEnv) <- tiImplGroups is
localEnv implEnv $ do
expls <- mapM tiExpl es
return (impls ++ fsts expls, mconcat (implEnv:env1:snds expls))
tiImplGroups :: [Either HsDecl [HsDecl]] -> Tc ([HsDecl], TypeEnv)
tiImplGroups [] = return ([],mempty)
tiImplGroups (Left x:xs) = do
(d,te) <- tiNonRecImpl x
(ds',te') <- localEnv te $ tiImplGroups xs
return (d:ds', te `mappend` te')
tiImplGroups (Right x:xs) = do
(ds,te) <- tiImpls x
(ds',te') <- localEnv te $ tiImplGroups xs
return (ds ++ ds', te `mappend` te')
tiNonRecImpl :: HsDecl -> Tc (HsDecl, TypeEnv)
tiNonRecImpl decl = withContext (locSimple (srcLoc decl) ("in the implicitly typed: " ++ show (getDeclName decl))) $ do
when (dump FD.BoxySteps) $ liftIO $ putStrLn $ "*** tiimpls " ++ show (getDeclName decl)
mv <- newMetaVar Sigma kindStar
(res,ps) <- listenPreds $ tcDecl decl mv
ps' <- flattenType ps
mv' <- flattenType mv
fs <- freeMetaVarsEnv
let vss = freeMetaVars mv'
gs = vss Set.\\ fs
(mvs,ds,rs) <- splitReduce (Set.toList fs) (Set.toList vss) ps'
addPreds ds
sc' <- if restricted [decl] then do
let gs' = gs Set.\\ Set.fromList (freeVars rs)
addPreds rs
quantify (Set.toList gs') [] mv'
else quantify (Set.toList gs) rs mv'
let f n s = do
let (TForAll vs _) = toSigma s
addCoerce n (ctAbs vs)
when (dump FD.BoxySteps) $ liftIO $ putStrLn $ "*** " ++ show n ++ " :: " ++ prettyPrintType s
return (n,s)
(n,s) <- f (getDeclName decl) sc'
let nenv = (Map.singleton n s)
addToCollectedEnv nenv
return (fst res, nenv)
tiImpls :: [HsDecl] -> Tc ([HsDecl], TypeEnv)
tiImpls [] = return ([],Map.empty)
tiImpls bs = withContext (locSimple (srcLoc bs) ("in the recursive implicitly typed: " ++ (show (map getDeclName bs)))) $ do
let names = map getDeclName bs
when (dump FD.BoxySteps) $ liftIO $ putStrLn $ "*** tiimpls " ++ show names
ts <- sequence [newMetaVar Tau kindStar | _ <- bs]
(res,ps) <- listenPreds $
local (tcRecursiveCalls_u (Set.union $ Set.fromList names)) $
localEnv (Map.fromList [ (d,s) | d <- names | s <- ts]) $
sequence [ tcDecl d s | d <- bs | s <- ts ]
ps' <- flattenType ps
ts' <- flattenType ts
fs <- freeMetaVarsEnv
let vss = map (Set.fromList . freeVars) ts'
gs = (Set.unions vss) Set.\\ fs
(mvs,ds,rs) <- splitReduce (Set.toList fs) (Set.toList $ foldr1 Set.intersection vss) ps'
addPreds ds
scs' <- if restricted bs then do
let gs' = gs Set.\\ Set.fromList (freeVars rs)
addPreds rs
mapM (quantify (Set.toList gs') []) ts'
else mapM (quantify (Set.toList gs) rs) ts'
let f n s = do
let (TForAll vs _) = toSigma s
addCoerce n (ctAbs vs)
when (dump FD.BoxySteps) $ liftIO $ putStrLn $ "*** " ++ show n ++ " :: " ++ prettyPrintType s
return (n,s)
nenv <- sequence [ f (getDeclName d) t | (d,_) <- res | t <- scs' ]
addToCollectedEnv (Map.fromList nenv)
return (fsts res, Map.fromList nenv)
tcRhs :: HsRhs -> Sigma -> Tc HsRhs
tcRhs rhs typ = case rhs of
HsUnGuardedRhs e -> do
e' <- tcExpr e typ
return (HsUnGuardedRhs e')
HsGuardedRhss as -> do
gas <- mapM (tcGuardedRhs typ) as
return (HsGuardedRhss gas)
tcPragmaDecl spec@HsPragmaSpecialize { hsDeclSrcLoc = sloc, hsDeclName = n, hsDeclType = t } = do
withContext (locMsg sloc "in the SPECIALIZE pragma" $ show n) ans where
ans = do
kt <- getKindEnv
t <- hsTypeToType kt t
let nn = toName Val n
sc <- lookupName nn
listenPreds $ sc `subsumes` t
addRule RuleSpec { ruleUniq = hsDeclUniq spec, ruleName = nn, ruleType = t, ruleSuper = hsDeclBool spec }
return [spec]
tcPragmaDecl (HsPragmaRules rs) = do
rs' <- mapM tcRule rs
return [HsPragmaRules rs']
-- foreign decls are accumulated by tiExpl
tcPragmaDecl fd@(HsForeignDecl _ _ n qt) = do
kt <- getKindEnv
s <- hsQualTypeToSigma kt qt
addToCollectedEnv (Map.singleton (toName Val n) s)
return []
tcPragmaDecl fd@(HsForeignExport _ e n qt) = do
kt <- getKindEnv
s <- hsQualTypeToSigma kt qt
addToCollectedEnv (Map.singleton (ffiExportName e) s)
return []
tcPragmaDecl _ = return []
tcRule prule@HsRule { hsRuleFreeVars = vs, hsRuleLeftExpr = e1, hsRuleRightExpr = e2, hsRuleSrcLoc = sloc } =
withContext (locMsg sloc "in the RULES pragma" $ hsRuleString prule) ans where
ans = do
vs' <- mapM dv vs
tr <- newBox kindStar
let (vs,envs) = unzip vs'
ch <- getClassHierarchy
((e1,rs1),(e2,rs2)) <- localEnv (mconcat envs) $ do
(e1,ps1) <- listenPreds (tcExpr e1 tr)
(e2,ps2) <- listenPreds (tcExpr e2 tr)
([],rs1) <- splitPreds ch [] ps1
([],rs2) <- splitPreds ch [] ps2
return ((e1,rs1),(e2,rs2))
mapM_ unBox vs
vs <- flattenType vs
tr <- flattenType tr
let mvs = Set.toList $ Set.unions $ map freeMetaVars (tr:vs)
nvs <- mapM (newVar . metaKind) mvs
sequence_ [ varBind mv (TVar v) | v <- nvs | mv <- mvs ]
(rs1,rs2) <- flattenType (rs1,rs2)
ch <- getClassHierarchy
rs1 <- return $ simplify ch rs1
rs2 <- return $ simplify ch rs2
-- SamB 2009.01.12:
-- This doesn't make any sense to me -- it seems to break stuff ...
-- assertEntailment rs1 rs2
return prule { hsRuleLeftExpr = e1, hsRuleRightExpr = e2 }
dv (n,Nothing) = do
v <- newMetaVar Tau kindStar
let env = (Map.singleton (toName Val n) v)
addToCollectedEnv env
return (v,env)
dv (n,Just t) = do
kt <- getKindEnv
tt <- hsTypeToType kt t
let env = (Map.singleton (toName Val n) tt)
addToCollectedEnv env
return (tt,env)
tcDecl :: HsDecl -> Sigma -> Tc (HsDecl,TypeEnv)
tcDecl decl@(HsActionDecl srcLoc pat@(HsPVar v) exp) typ = withContext (declDiagnostic decl) $ do
typ <- evalType typ
(pat',env) <- tcPat pat typ
let tio = TCon (Tycon tc_IO (Kfun kindStar kindStar))
e' <- tcExpr exp (TAp tio typ)
return (decl { hsDeclPat = pat', hsDeclExp = e' }, Map.singleton (toName Val v) typ)
tcDecl decl@(HsPatBind sloc (HsPVar v) rhs wheres) typ = withContext (declDiagnostic decl) $ do
typ <- evalType typ
(wheres', env) <- tcWheres wheres
localEnv env $ do
case rhs of
HsUnGuardedRhs e -> do
e' <- tcExpr e typ
return (HsPatBind sloc (HsPVar v) (HsUnGuardedRhs e') wheres', Map.singleton (toName Val v) typ)
HsGuardedRhss as -> do
gas <- mapM (tcGuardedRhs typ) as
return (HsPatBind sloc (HsPVar v) (HsGuardedRhss gas) wheres', Map.singleton (toName Val v) typ)
tcDecl decl@(HsFunBind matches) typ = withContext (declDiagnostic decl) $ do
typ <- evalType typ
matches' <- mapM (`tcMatch` typ) matches
return (HsFunBind matches', Map.singleton (getDeclName decl) typ)
tcMatch :: HsMatch -> Sigma -> Tc HsMatch
tcMatch (HsMatch sloc funName pats rhs wheres) typ = withContext (locMsg sloc "in" $ show funName) $ do
let lam (p:ps) (TMetaVar mv) rs = do -- ABS2
withMetaVars mv [kindArg,kindFunRet] (\ [a,b] -> a `fn` b) $ \ [a,b] -> lam (p:ps) (a `fn` b) rs
lam (p:ps) ty@(TArrow s1' s2') rs = do -- ABS1
(p',env) <- tcPat p s1'
localEnv env $ do
s2' <- evalType s2'
lamPoly ps s2' (p':rs)
lam [] typ rs = do
(wheres', env) <- tcWheres wheres
rhs <- localEnv env $ tcRhs rhs typ
return (HsMatch sloc funName (reverse rs) rhs wheres')
lam _ t _ = do
t <- flattenType t
fail $ "expected a -> b, found: " ++ prettyPrintType t
lamPoly ps s@TMetaVar {} rs = lam ps s rs
lamPoly ps s rs = do
(_,_,s) <- skolomize s
lam ps s rs
typ <- evalType typ
res <- lam pats typ []
return res
declDiagnostic :: (HsDecl) -> Diagnostic
declDiagnostic decl@(HsPatBind sloc (HsPVar {}) _ _) = locMsg sloc "in the declaration" $ render $ ppHsDecl decl
declDiagnostic decl@(HsPatBind sloc pat _ _) = locMsg sloc "in the pattern binding" $ render $ ppHsDecl decl
declDiagnostic decl@(HsFunBind matches) = locMsg (srcLoc decl) "in the function binding" $ render $ ppHsDecl decl
tiExpl :: Expl -> Tc (HsDecl,TypeEnv)
tiExpl (sc, decl@HsForeignDecl {}) = do return (decl,Map.empty)
tiExpl (sc, decl@HsForeignExport {}) = do return (decl,Map.empty)
tiExpl (sc, decl) = withContext (locSimple (srcLoc decl) ("in the explicitly typed " ++ (render $ ppHsDecl decl))) $ do
when (dump FD.BoxySteps) $ liftIO $ putStrLn $ "** typing expl: " ++ show (getDeclName decl) ++ " " ++ prettyPrintType sc
sc <- evalFullType sc
(vs,qs,typ) <- skolomize sc
let sc' = (tForAll vs (qs :=> typ))
mp = (Map.singleton (getDeclName decl) sc')
addCoerce (getDeclName decl) (ctAbs vs)
addToCollectedEnv mp
(ret,ps) <- localEnv mp $ listenPreds (tcDecl decl typ)
ps <- flattenType ps
ch <- getClassHierarchy
env <- freeMetaVarsEnv
(_,ds,rs) <- splitReduce (Set.toList env) (freeMetaVarsPreds qs) ps
assertEntailment qs (rs ++ ds)
return ret
restricted :: [HsDecl] -> Bool
restricted bs = any isHsActionDecl bs || (fopts FO.MonomorphismRestriction && any isSimpleDecl bs) where
isSimpleDecl :: (HsDecl) -> Bool
isSimpleDecl (HsPatBind _sloc _pat _rhs _wheres) = True
isSimpleDecl _ = False
{-
--------------------------------------------------------------------------------
tiStmts :: TypeEnv -> [(HsStmt)] -> TI ([Pred], TypeEnv)
tiStmts = tiStmtsAcc [] Map.empty
tiStmtsAcc :: [Pred] -> TypeEnv -> TypeEnv -> [(HsStmt)] -> TI ([Pred], TypeEnv)
tiStmtsAcc predAcc envAcc _ []
= return (predAcc, envAcc)
tiStmtsAcc predAcc envAcc env (s:ss)
= do
(newPs, newEnv) <- tiStmt (envAcc `Map.union` env) s
tiStmtsAcc (newPs ++ predAcc) (newEnv `Map.union` envAcc) env ss
tiStmt :: TypeEnv -> (HsStmt) -> TI ([Pred], TypeEnv)
-- with lists:
-- x <- xs
-- xs :: [a]
-- x :: a
tiStmt env expr@(HsGenerator srcLoc pat e)
= withContext
(locMsg srcLoc "in the generator " $ render $ ppHsStmt expr) $
do
(ePs, eEnv, eT) <- tiExpr env e
(patPs, patEnv, patT) <- tiPat pat
unify eT (TAp tList patT)
return (ePs ++ patPs, eEnv `Map.union` patEnv)
tiStmt env stmt@(HsQualifier e)
= withContext (makeMsg "in " $ render $ ppHsStmt stmt) $
do
(ePs, eEnv, eT) <- tiExpr env e
unify eT tBool
return (ePs, eEnv)
tiStmt env stmt@(HsLetStmt decls)
= withContext
(makeMsg "in let statement" $ render $ ppHsStmt stmt) $
do
sigEnv <- getSigEnv
let bgs = getFunDeclsBg sigEnv decls
tiSeq tiBindGroup env bgs
--------------------------------------------------------------------------------
-}
getBindGroupName (expl,impls) = map getDeclName (snds expl ++ concat (rights impls) ++ lefts impls)
tiProgram :: [BindGroup] -> [HsDecl] -> Tc [HsDecl]
tiProgram bgs es = ans where
ans = do
(r,ps) <- listenPreds $ f bgs [] mempty
ps <- flattenType ps
ch <- getClassHierarchy
([],rs) <- splitPreds ch [] ps
topDefaults rs
return r
--ps <- return $ simplify ch ps
--liftIO $ mapM_ (putStrLn.show) ps
--return r
f (bg:bgs) rs cenv = do
((ds,env),ps) <- listenPreds (tcBindGroup bg)
ch <- getClassHierarchy
withContext (makeMsg "in the binding group:" $ show (getBindGroupName bg)) $ do
([],leftovers) <- splitPreds ch [] ps
--topDefaults leftovers
return ()
when verbose $ liftIO $ do putChar '.'; hFlush stdout
localEnv env $ f bgs (ds ++ rs) (env `mappend` cenv)
f [] rs _cenv = do
ch <- getClassHierarchy
(pdecls,ps) <- listenPreds $ mapM tcPragmaDecl es
withContext (makeMsg "in the pragmas:" $ "rules") $ do
([],leftovers) <- splitPreds ch [] ps
--topDefaults leftovers
return ()
when verbose $ liftIO $ putStrLn "!"
return (rs ++ concat pdecls)
-- Typing Literals
tiLit :: HsLiteral -> Tc Tau
tiLit (HsChar _) = return tChar
tiLit (HsInt _) = do
v <- newVar kindStar
return $ TForAll [v] ([IsIn class_Num (TVar v)] :=> TVar v)
--(v) <- newBox Star
--addPreds [IsIn class_Num v]
--return v
tiLit (HsFrac _) = do
v <- newVar kindStar
return $ TForAll [v] ([IsIn class_Fractional (TVar v)] :=> TVar v)
-- (v) <- newBox Star
-- addPreds [IsIn class_Fractional v]
-- return v
tiLit (HsStringPrim _) = return (TCon (Tycon tc_BitsPtr kindHash))
tiLit (HsString _) = return tString
--tiProgram = undefined
------------------------------------------
-- Binding analysis and program generation
------------------------------------------
-- create a Program structure from a list of decls and
-- type sigs. Type sigs are associated with corresponding
-- decls if they exist
getFunDeclsBg :: TypeEnv -> [HsDecl] -> [BindGroup]
getFunDeclsBg sigEnv decls = makeProgram sigEnv equationGroups where
equationGroups :: [[HsDecl]]
equationGroups = getBindGroups bindDecls (nameName . getDeclName) getDeclDeps
bindDecls = collectBindDecls decls
getBindGroups :: Ord name =>
[node] -> -- List of nodes
(node -> name) -> -- Function to convert nodes to a unique name
(node -> [name]) -> -- Function to return dependencies of this node
[[node]] -- Bindgroups
getBindGroups ns fn fd = map f $ stronglyConnComp [ (n, fn n, fd n) | n <- ns] where
f (AcyclicSCC x) = [x]
f (CyclicSCC xs) = xs
-- | make a program from a set of binding groups
makeProgram :: TypeEnv -> [[HsDecl]] -> [BindGroup]
makeProgram sigEnv groups = map (makeBindGroup sigEnv ) groups
-- | reunite decls with their signatures, if ever they had one
makeBindGroup :: TypeEnv -> [HsDecl] -> BindGroup
makeBindGroup sigEnv decls = (exps, f impls) where
(exps, impls) = makeBindGroup' sigEnv decls
enames = map (nameName . getDeclName . snd) exps
f xs = map g $ stronglyConnComp [ (x, nameName $ getDeclName x,[ d | d <- getDeclDeps x, d `notElem` enames]) | x <- xs]
g (AcyclicSCC x) = Left x
g (CyclicSCC xs) = Right xs
makeBindGroup' _ [] = ([], [])
makeBindGroup' sigEnv (d:ds) = case Map.lookup funName sigEnv of
Nothing -> (restExpls, d:restImpls)
Just scheme -> ((scheme, d):restExpls, restImpls)
where
funName = getDeclName d
(restExpls, restImpls) = makeBindGroup' sigEnv ds
collectBindDecls :: [HsDecl] -> [HsDecl]
collectBindDecls = filter isBindDecl where
isBindDecl :: HsDecl -> Bool
isBindDecl HsActionDecl {} = True
isBindDecl HsPatBind {} = True
isBindDecl HsFunBind {} = True
isBindDecl _ = False