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gf-core/src/GF/Compile/CheckGrammar.hs
2009-10-06 14:59:02 +00:00

1007 lines
37 KiB
Haskell

{-# LANGUAGE PatternGuards #-}
----------------------------------------------------------------------
-- |
-- Module : CheckGrammar
-- Maintainer : AR
-- Stability : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 2005/11/11 23:24:33 $
-- > CVS $Author: aarne $
-- > CVS $Revision: 1.31 $
--
-- AR 4\/12\/1999 -- 1\/4\/2000 -- 8\/9\/2001 -- 15\/5\/2002 -- 27\/11\/2002 -- 18\/6\/2003
--
-- type checking also does the following modifications:
--
-- - types of operations and local constants are inferred and put in place
--
-- - both these types and linearization types are computed
--
-- - tables are type-annotated
-----------------------------------------------------------------------------
module GF.Compile.CheckGrammar (
checkModule, inferLType, allOperDependencies, topoSortOpers) where
import GF.Infra.Ident
import GF.Infra.Modules
import GF.Compile.TypeCheck
import GF.Compile.Refresh
import GF.Grammar.Lexer
import GF.Grammar.Grammar
import GF.Grammar.Printer
import GF.Grammar.Lookup
import GF.Grammar.Predef
import GF.Grammar.Macros
import GF.Grammar.PatternMatch
import GF.Grammar.AppPredefined
import GF.Grammar.Lockfield (isLockLabel, lockRecType, unlockRecord)
import GF.Data.Operations
import GF.Infra.CheckM
import Data.List
import qualified Data.Set as Set
import Control.Monad
import Text.PrettyPrint
-- | checking is performed in the dependency order of modules
checkModule :: [SourceModule] -> SourceModule -> Check SourceModule
checkModule ms (name,mo) = checkIn (text "checking module" <+> ppIdent name) $ do
let js = jments mo
checkRestrictedInheritance ms (name, mo)
js' <- case mtype mo of
MTAbstract -> checkMap (checkAbsInfo gr name mo) js
MTResource -> checkMap (checkResInfo gr name mo) js
MTConcrete a -> do
checkErr $ topoSortOpers $ allOperDependencies name js
abs <- checkErr $ lookupModule gr a
js1 <- checkCompleteGrammar gr abs mo
checkMap (checkCncInfo gr name mo (a,abs)) js1
MTInterface -> checkMap (checkResInfo gr name mo) js
MTInstance a -> do
checkMap (checkResInfo gr name mo) js
return (name, replaceJudgements mo js')
where
gr = MGrammar $ (name,mo):ms
-- check if restricted inheritance modules are still coherent
-- i.e. that the defs of remaining names don't depend on omitted names
checkRestrictedInheritance :: [SourceModule] -> SourceModule -> Check ()
checkRestrictedInheritance mos (name,mo) = do
let irs = [ii | ii@(_,mi) <- extend mo, mi /= MIAll] -- names with restr. inh.
let mrs = [((i,m),mi) | (i,m) <- mos, Just mi <- [lookup i irs]]
-- the restr. modules themself, with restr. infos
mapM_ checkRem mrs
where
checkRem ((i,m),mi) = do
let (incl,excl) = partition (isInherited mi) (map fst (tree2list (jments m)))
let incld c = Set.member c (Set.fromList incl)
let illegal c = Set.member c (Set.fromList excl)
let illegals = [(f,is) |
(f,cs) <- allDeps, incld f, let is = filter illegal cs, not (null is)]
case illegals of
[] -> return ()
cs -> checkError (text "In inherited module" <+> ppIdent i <> text ", dependence of excluded constants:" $$
nest 2 (vcat [ppIdent f <+> text "on" <+> fsep (map ppIdent is) | (f,is) <- cs]))
allDeps = concatMap (allDependencies (const True) . jments . snd) mos
checkAbsInfo ::
SourceGrammar -> Ident -> SourceModInfo -> Ident -> Info -> Check Info
checkAbsInfo st m mo c info = do
checkReservedId c
case info of
AbsCat (Just cont) _ -> mkCheck "category" $
checkContext st cont ---- also cstrs
AbsFun (Just typ0) ma md -> do
typ <- compAbsTyp [] typ0 -- to calculate let definitions
mkCheck "type of function" $
checkTyp st typ
case md of
Just eqs -> mkCheck "definition of function" $
checkDef st (m,c) typ eqs
Nothing -> return info
return $ (AbsFun (Just typ) ma md)
_ -> return info
where
mkCheck cat ss = case ss of
[] -> return info
_ -> checkError (vcat ss $$ text "in" <+> text cat <+> ppIdent c <+> ppPosition mo c)
compAbsTyp g t = case t of
Vr x -> maybe (checkError (text "no value given to variable" <+> ppIdent x)) return $ lookup x g
Let (x,(_,a)) b -> do
a' <- compAbsTyp g a
compAbsTyp ((x, a'):g) b
Prod b x a t -> do
a' <- compAbsTyp g a
t' <- compAbsTyp ((x,Vr x):g) t
return $ Prod b x a' t'
Abs _ _ _ -> return t
_ -> composOp (compAbsTyp g) t
checkCompleteGrammar :: SourceGrammar -> SourceModInfo -> SourceModInfo -> Check (BinTree Ident Info)
checkCompleteGrammar gr abs cnc = do
let jsa = jments abs
let fsa = tree2list jsa
let jsc = jments cnc
let fsc = map fst $ filter (isCnc . snd) $ tree2list jsc
-- remove those lincat and lin in concrete that are not in abstract
let unkn = filter (not . flip isInBinTree jsa) fsc
jsc1 <- if (null unkn) then return jsc else do
checkWarn $ text "ignoring constants not in abstract:" <+> fsep (map ppIdent unkn)
return $ filterBinTree (\f _ -> notElem f unkn) jsc
-- check that all abstract constants are in concrete; build default lincats
foldM checkOne jsc1 fsa
where
isCnc j = case j of
CncFun _ _ _ -> True
CncCat _ _ _ -> True
_ -> False
checkOne js i@(c,info) = case info of
AbsFun (Just ty) _ _ -> do let mb_def = do
let (cxt,(_,i),_) = typeForm ty
info <- lookupIdent i js
info <- case info of
(AnyInd _ m) -> do (m,info) <- lookupOrigInfo gr m i
return info
_ -> return info
case info of
CncCat (Just (RecType [])) _ _ -> return (foldr (\_ -> Abs Explicit identW) (R []) cxt)
_ -> Bad "no def lin"
case lookupIdent c js of
Ok (CncFun _ (Just _) _ ) -> return js
Ok (CncFun cty Nothing pn) ->
case mb_def of
Ok def -> return $ updateTree (c,CncFun cty (Just def) pn) js
Bad _ -> do checkWarn $ text "no linearization of" <+> ppIdent c
return js
_ -> do
case mb_def of
Ok def -> return $ updateTree (c,CncFun Nothing (Just def) Nothing) js
Bad _ -> do checkWarn $ text "no linearization of" <+> ppIdent c
return js
AbsCat (Just _) _ -> case lookupIdent c js of
Ok (AnyInd _ _) -> return js
Ok (CncCat (Just _) _ _) -> return js
Ok (CncCat _ mt mp) -> do
checkWarn $
text "no linearization type for" <+> ppIdent c <> text ", inserting default {s : Str}"
return $ updateTree (c,CncCat (Just defLinType) mt mp) js
_ -> do
checkWarn $
text "no linearization type for" <+> ppIdent c <> text ", inserting default {s : Str}"
return $ updateTree (c,CncCat (Just defLinType) Nothing Nothing) js
_ -> return js
-- | General Principle: only Just-values are checked.
-- A May-value has always been checked in its origin module.
checkResInfo :: SourceGrammar -> Ident -> SourceModInfo -> Ident -> Info -> Check Info
checkResInfo gr mo mm c info = do
checkReservedId c
case info of
ResOper pty pde -> chIn "operation" $ do
(pty', pde') <- case (pty,pde) of
(Just ty, Just de) -> do
ty' <- checkLType gr [] ty typeType >>= computeLType gr [] . fst
(de',_) <- checkLType gr [] de ty'
return (Just ty', Just de')
(_ , Just de) -> do
(de',ty') <- inferLType gr [] de
return (Just ty', Just de')
(_ , Nothing) -> do
checkError (text "No definition given to the operation")
return (ResOper pty' pde')
ResOverload os tysts -> chIn "overloading" $ do
tysts' <- mapM (uncurry $ flip (checkLType gr [])) tysts -- return explicit ones
tysts0 <- checkErr $ lookupOverload gr mo c -- check against inherited ones too
tysts1 <- mapM (uncurry $ flip (checkLType gr []))
[(mkFunType args val,tr) | (args,(val,tr)) <- tysts0]
--- this can only be a partial guarantee, since matching
--- with value type is only possible if expected type is given
checkUniq $
sort [let (xs,t) = typeFormCnc x in t : map (\(b,x,t) -> t) xs | (_,x) <- tysts1]
return (ResOverload os [(y,x) | (x,y) <- tysts'])
ResParam (Just (pcs,_)) -> chIn "parameter type" $ do
ts <- checkErr $ lookupParamValues gr mo c
return (ResParam (Just (pcs, Just ts)))
_ -> return info
where
chIn cat = checkIn (text "Happened in" <+> text cat <+> ppIdent c <+> ppPosition mm c <+> colon)
checkUniq xss = case xss of
x:y:xs
| x == y -> checkError $ text "ambiguous for type" <+>
ppType (mkFunType (tail x) (head x))
| otherwise -> checkUniq $ y:xs
_ -> return ()
checkCncInfo :: SourceGrammar -> Ident -> SourceModInfo ->
(Ident,SourceModInfo) ->
Ident -> Info -> Check Info
checkCncInfo gr m mo (a,abs) c info = do
checkReservedId c
case info of
CncFun _ (Just trm) mpr -> chIn "linearization of" $ do
typ <- checkErr $ lookupFunType gr a c
let cat0 = valCat typ
(cont,val) <- linTypeOfType gr m typ -- creates arg vars
(trm',_) <- checkLType gr [] trm (mkFunType (map (\(_,_,ty) -> ty) cont) val) -- erases arg vars
checkPrintname gr mpr
cat <- return $ snd cat0
return (CncFun (Just (cat,(cont,val))) (Just trm') mpr)
-- cat for cf, typ for pe
CncCat (Just typ) mdef mpr -> chIn "linearization type of" $ do
checkErr $ lookupCatContext gr a c
typ' <- computeLType gr [] typ
mdef' <- case mdef of
Just def -> do
(def',_) <- checkLType gr [] def (mkFunType [typeStr] typ)
return $ Just def'
_ -> return mdef
checkPrintname gr mpr
return (CncCat (Just typ') mdef' mpr)
_ -> checkResInfo gr m mo c info
where
chIn cat = checkIn (text "Happened in" <+> text cat <+> ppIdent c <+> ppPosition mo c <> colon)
computeLType :: SourceGrammar -> Context -> Type -> Check Type
computeLType gr g0 t = comp (reverse [(b,x, Vr x) | (b,x,_) <- g0] ++ g0) t
where
comp g ty = case ty of
_ | Just _ <- isTypeInts ty -> return ty ---- shouldn't be needed
| isPredefConstant ty -> return ty ---- shouldn't be needed
Q m ident -> checkIn (text "module" <+> ppIdent m) $ do
ty' <- checkErr (lookupResDef gr m ident)
if ty' == ty then return ty else comp g ty' --- is this necessary to test?
Vr ident -> checkLookup ident g -- never needed to compute!
App f a -> do
f' <- comp g f
a' <- comp g a
case f' of
Abs b x t -> comp ((b,x,a'):g) t
_ -> return $ App f' a'
Prod bt x a b -> do
a' <- comp g a
b' <- comp ((bt,x,Vr x) : g) b
return $ Prod bt x a' b'
Abs bt x b -> do
b' <- comp ((bt,x,Vr x):g) b
return $ Abs bt x b'
ExtR r s -> do
r' <- comp g r
s' <- comp g s
case (r',s') of
(RecType rs, RecType ss) -> checkErr (plusRecType r' s') >>= comp g
_ -> return $ ExtR r' s'
RecType fs -> do
let fs' = sortRec fs
liftM RecType $ mapPairsM (comp g) fs'
ELincat c t -> do
t' <- comp g t
checkErr $ lockRecType c t' ---- locking to be removed AR 20/6/2009
_ | ty == typeTok -> return typeStr
_ | isPredefConstant ty -> return ty
_ -> composOp (comp g) ty
checkPrintname :: SourceGrammar -> Maybe Term -> Check ()
checkPrintname st (Just t) = checkLType st [] t typeStr >> return ()
checkPrintname _ _ = return ()
-- | for grammars obtained otherwise than by parsing ---- update!!
checkReservedId :: Ident -> Check ()
checkReservedId x
| isReservedWord (ident2bs x) = checkWarn (text "reserved word used as identifier:" <+> ppIdent x)
| otherwise = return ()
-- the underlying algorithms
inferLType :: SourceGrammar -> Context -> Term -> Check (Term, Type)
inferLType gr g trm = case trm of
Q m ident | isPredef m -> termWith trm $ checkErr (typPredefined ident)
Q m ident -> checks [
termWith trm $ checkErr (lookupResType gr m ident) >>= computeLType gr g
,
checkErr (lookupResDef gr m ident) >>= inferLType gr g
,
checkError (text "cannot infer type of constant" <+> ppTerm Unqualified 0 trm)
]
QC m ident | isPredef m -> termWith trm $ checkErr (typPredefined ident)
QC m ident -> checks [
termWith trm $ checkErr (lookupResType gr m ident) >>= computeLType gr g
,
checkErr (lookupResDef gr m ident) >>= inferLType gr g
,
checkError (text "cannot infer type of canonical constant" <+> ppTerm Unqualified 0 trm)
]
Val _ ty i -> termWith trm $ return ty
Vr ident -> termWith trm $ checkLookup ident g
Typed e t -> do
t' <- computeLType gr g t
checkLType gr g e t'
return (e,t')
App f a -> do
over <- getOverload gr g Nothing trm
case over of
Just trty -> return trty
_ -> do
(f',fty) <- inferLType gr g f
fty' <- computeLType gr g fty
case fty' of
Prod bt z arg val -> do
a' <- justCheck g a arg
ty <- if isWildIdent z
then return val
else substituteLType [(bt,z,a')] val
return (App f' a',ty)
_ -> checkError (text "A function type is expected for" <+> ppTerm Unqualified 0 f <+> text "instead of type" <+> ppType fty)
S f x -> do
(f', fty) <- inferLType gr g f
case fty of
Table arg val -> do
x'<- justCheck g x arg
return (S f' x', val)
_ -> checkError (text "table lintype expected for the table in" $$ nest 2 (ppTerm Unqualified 0 trm))
P t i -> do
(t',ty) <- inferLType gr g t --- ??
ty' <- computeLType gr g ty
let tr2 = P t' i
termWith tr2 $ case ty' of
RecType ts -> case lookup i ts of
Nothing -> checkError (text "unknown label" <+> ppLabel i <+> text "in" $$ nest 2 (ppTerm Unqualified 0 ty'))
Just x -> return x
_ -> checkError (text "record type expected for:" <+> ppTerm Unqualified 0 t $$
text " instead of the inferred:" <+> ppTerm Unqualified 0 ty')
PI t i _ -> inferLType gr g $ P t i
R r -> do
let (ls,fs) = unzip r
fsts <- mapM inferM fs
let ts = [ty | (Just ty,_) <- fsts]
checkCond (text "cannot infer type of record" $$ nest 2 (ppTerm Unqualified 0 trm)) (length ts == length fsts)
return $ (R (zip ls fsts), RecType (zip ls ts))
T (TTyped arg) pts -> do
(_,val) <- checks $ map (inferCase (Just arg)) pts
checkLType gr g trm (Table arg val)
T (TComp arg) pts -> do
(_,val) <- checks $ map (inferCase (Just arg)) pts
checkLType gr g trm (Table arg val)
T ti pts -> do -- tries to guess: good in oper type inference
let pts' = [pt | pt@(p,_) <- pts, isConstPatt p]
case pts' of
[] -> checkError (text "cannot infer table type of" <+> ppTerm Unqualified 0 trm)
---- PInt k : _ -> return $ Ints $ max [i | PInt i <- pts']
_ -> do
(arg,val) <- checks $ map (inferCase Nothing) pts'
checkLType gr g trm (Table arg val)
V arg pts -> do
(_,val) <- checks $ map (inferLType gr g) pts
return (trm, Table arg val)
K s -> do
if elem ' ' s
then do
let ss = foldr C Empty (map K (words s))
----- removed irritating warning AR 24/5/2008
----- checkWarn ("token \"" ++ s ++
----- "\" converted to token list" ++ prt ss)
return (ss, typeStr)
else return (trm, typeStr)
EInt i -> return (trm, typeInt)
EFloat i -> return (trm, typeFloat)
Empty -> return (trm, typeStr)
C s1 s2 ->
check2 (flip (justCheck g) typeStr) C s1 s2 typeStr
Glue s1 s2 ->
check2 (flip (justCheck g) typeStr) Glue s1 s2 typeStr ---- typeTok
---- hack from Rename.identRenameTerm, to live with files with naming conflicts 18/6/2007
Strs (Cn c : ts) | c == cConflict -> do
checkWarn (text "unresolved constant, could be any of" <+> hcat (map (ppTerm Unqualified 0) ts))
inferLType gr g (head ts)
Strs ts -> do
ts' <- mapM (\t -> justCheck g t typeStr) ts
return (Strs ts', typeStrs)
Alts (t,aa) -> do
t' <- justCheck g t typeStr
aa' <- flip mapM aa (\ (c,v) -> do
c' <- justCheck g c typeStr
v' <- checks $ map (justCheck g v) [typeStrs, EPattType typeStr]
return (c',v'))
return (Alts (t',aa'), typeStr)
RecType r -> do
let (ls,ts) = unzip r
ts' <- mapM (flip (justCheck g) typeType) ts
return (RecType (zip ls ts'), typeType)
ExtR r s -> do
(r',rT) <- inferLType gr g r
rT' <- computeLType gr g rT
(s',sT) <- inferLType gr g s
sT' <- computeLType gr g sT
let trm' = ExtR r' s'
---- trm' <- checkErr $ plusRecord r' s'
case (rT', sT') of
(RecType rs, RecType ss) -> do
rt <- checkErr $ plusRecType rT' sT'
checkLType gr g trm' rt ---- return (trm', rt)
_ | rT' == typeType && sT' == typeType -> return (trm', typeType)
_ -> checkError (text "records or record types expected in" <+> ppTerm Unqualified 0 trm)
Sort _ ->
termWith trm $ return typeType
Prod bt x a b -> do
a' <- justCheck g a typeType
b' <- justCheck ((bt,x,a'):g) b typeType
return (Prod bt x a' b', typeType)
Table p t -> do
p' <- justCheck g p typeType --- check p partype!
t' <- justCheck g t typeType
return $ (Table p' t', typeType)
FV vs -> do
(_,ty) <- checks $ map (inferLType gr g) vs
--- checkIfComplexVariantType trm ty
checkLType gr g trm ty
EPattType ty -> do
ty' <- justCheck g ty typeType
return (EPattType ty',typeType)
EPatt p -> do
ty <- inferPatt p
return (trm, EPattType ty)
ELin c trm -> do
(trm',ty) <- inferLType gr g trm
ty' <- checkErr $ lockRecType c ty ---- lookup c; remove lock AR 20/6/2009
return $ (ELin c trm', ty')
_ -> checkError (text "cannot infer lintype of" <+> ppTerm Unqualified 0 trm)
where
isPredef m = elem m [cPredef,cPredefAbs]
justCheck g ty te = checkLType gr g ty te >>= return . fst
-- for record fields, which may be typed
inferM (mty, t) = do
(t', ty') <- case mty of
Just ty -> checkLType gr g ty t
_ -> inferLType gr g t
return (Just ty',t')
inferCase mty (patt,term) = do
arg <- maybe (inferPatt patt) return mty
cont <- pattContext gr g arg patt
(_,val) <- inferLType gr (reverse cont ++ g) term
return (arg,val)
isConstPatt p = case p of
PC _ ps -> True --- all isConstPatt ps
PP _ _ ps -> True --- all isConstPatt ps
PR ps -> all (isConstPatt . snd) ps
PT _ p -> isConstPatt p
PString _ -> True
PInt _ -> True
PFloat _ -> True
PChar -> True
PChars _ -> True
PSeq p q -> isConstPatt p && isConstPatt q
PAlt p q -> isConstPatt p && isConstPatt q
PRep p -> isConstPatt p
PNeg p -> isConstPatt p
PAs _ p -> isConstPatt p
_ -> False
inferPatt p = case p of
PP q c ps | q /= cPredef -> checkErr $ liftM valTypeCnc (lookupResType gr q c)
PAs _ p -> inferPatt p
PNeg p -> inferPatt p
PAlt p q -> checks [inferPatt p, inferPatt q]
PSeq _ _ -> return $ typeStr
PRep _ -> return $ typeStr
PChar -> return $ typeStr
PChars _ -> return $ typeStr
_ -> inferLType gr g (patt2term p) >>= return . snd
-- type inference: Nothing, type checking: Just t
-- the latter permits matching with value type
getOverload :: SourceGrammar -> Context -> Maybe Type -> Term -> Check (Maybe (Term,Type))
getOverload gr g mt ot = case appForm ot of
(f@(Q m c), ts) -> case lookupOverload gr m c of
Ok typs -> do
ttys <- mapM (inferLType gr g) ts
v <- matchOverload f typs ttys
return $ Just v
_ -> return Nothing
_ -> return Nothing
where
matchOverload f typs ttys = do
let (tts,tys) = unzip ttys
let vfs = lookupOverloadInstance tys typs
let matches = [vf | vf@((v,_),_) <- vfs, matchVal mt v]
case ([vf | (vf,True) <- matches],[vf | (vf,False) <- matches]) of
([(val,fun)],_) -> return (mkApp fun tts, val)
([],[(val,fun)]) -> do
checkWarn (text "ignoring lock fields in resolving" <+> ppTerm Unqualified 0 ot)
return (mkApp fun tts, val)
([],[]) -> do
let showTypes ty = hsep (map ppType ty)
checkError $ text "no overload instance of" <+> ppTerm Unqualified 0 f $$
text "for" $$
nest 2 (showTypes tys) $$
text "among" $$
nest 2 (vcat [showTypes ty | (ty,_) <- typs]) $$
maybe empty (\x -> text "with value type" <+> ppType x) mt
(vfs1,vfs2) -> case (noProds vfs1,noProds vfs2) of
([(val,fun)],_) -> do
return (mkApp fun tts, val)
([],[(val,fun)]) -> do
checkWarn (text "ignoring lock fields in resolving" <+> ppTerm Unqualified 0 ot)
return (mkApp fun tts, val)
----- unsafely exclude irritating warning AR 24/5/2008
----- checkWarn $ "overloading of" +++ prt f +++
----- "resolved by excluding partial applications:" ++++
----- unlines [prtType env ty | (ty,_) <- vfs', not (noProd ty)]
_ -> checkError $ text "ambiguous overloading of" <+> ppTerm Unqualified 0 f <+>
text "for" <+> hsep (map ppType tys) $$
text "with alternatives" $$
nest 2 (vcat [ppType ty | (ty,_) <- if null vfs1 then vfs2 else vfs2])
matchVal mt v = elem mt [Nothing,Just v,Just (unlocked v)]
unlocked v = case v of
RecType fs -> RecType $ filter (not . isLockLabel . fst) fs
_ -> v
---- TODO: accept subtypes
---- TODO: use a trie
lookupOverloadInstance tys typs =
[((mkFunType rest val, t),isExact) |
let lt = length tys,
(ty,(val,t)) <- typs, length ty >= lt,
let (pre,rest) = splitAt lt ty,
let isExact = pre == tys,
isExact || map unlocked pre == map unlocked tys
]
noProds vfs = [(v,f) | (v,f) <- vfs, noProd v]
noProd ty = case ty of
Prod _ _ _ _ -> False
_ -> True
checkLType :: SourceGrammar -> Context -> Term -> Type -> Check (Term, Type)
checkLType gr g trm typ0 = do
typ <- computeLType gr g typ0
case trm of
Abs bt x c -> do
case typ of
Prod bt' z a b -> do
(c',b') <- if isWildIdent z
then checkLType gr ((bt,x,a):g) c b
else do b' <- checkIn (text "abs") $ substituteLType [(bt',z,Vr x)] b
checkLType gr ((bt,x,a):g) c b'
return $ (Abs bt x c', Prod bt' x a b')
_ -> checkError $ text "function type expected instead of" <+> ppType typ
App f a -> do
over <- getOverload gr g (Just typ) trm
case over of
Just trty -> return trty
_ -> do
(trm',ty') <- inferLType gr g trm
termWith trm' $ checkEqLType gr g typ ty' trm'
Q _ _ -> do
over <- getOverload gr g (Just typ) trm
case over of
Just trty -> return trty
_ -> do
(trm',ty') <- inferLType gr g trm
termWith trm' $ checkEqLType gr g typ ty' trm'
T _ [] ->
checkError (text "found empty table in type" <+> ppTerm Unqualified 0 typ)
T _ cs -> case typ of
Table arg val -> do
case allParamValues gr arg of
Ok vs -> do
let ps0 = map fst cs
ps <- checkErr $ testOvershadow ps0 vs
if null ps
then return ()
else checkWarn (text "patterns never reached:" $$
nest 2 (vcat (map (ppPatt Unqualified 0) ps)))
_ -> return () -- happens with variable types
cs' <- mapM (checkCase arg val) cs
return (T (TTyped arg) cs', typ)
_ -> checkError $ text "table type expected for table instead of" $$ nest 2 (ppType typ)
R r -> case typ of --- why needed? because inference may be too difficult
RecType rr -> do
let (ls,_) = unzip rr -- labels of expected type
fsts <- mapM (checkM r) rr -- check that they are found in the record
return $ (R fsts, typ) -- normalize record
_ -> checkError (text "record type expected in type checking instead of" $$ nest 2 (ppTerm Unqualified 0 typ))
ExtR r s -> case typ of
_ | typ == typeType -> do
trm' <- computeLType gr g trm
case trm' of
RecType _ -> termWith trm $ return typeType
ExtR (Vr _) (RecType _) -> termWith trm $ return typeType
-- ext t = t ** ...
_ -> checkError (text "invalid record type extension" <+> nest 2 (ppTerm Unqualified 0 trm))
RecType rr -> do
(r',ty,s') <- checks [
do (r',ty) <- inferLType gr g r
return (r',ty,s)
,
do (s',ty) <- inferLType gr g s
return (s',ty,r)
]
case ty of
RecType rr1 -> do
let (rr0,rr2) = recParts rr rr1
r2 <- justCheck g r' rr0
s2 <- justCheck g s' rr2
return $ (ExtR r2 s2, typ)
_ -> checkError (text "record type expected in extension of" <+> ppTerm Unqualified 0 r $$
text "but found" <+> ppTerm Unqualified 0 ty)
ExtR ty ex -> do
r' <- justCheck g r ty
s' <- justCheck g s ex
return $ (ExtR r' s', typ) --- is this all?
_ -> checkError (text "record extension not meaningful for" <+> ppTerm Unqualified 0 typ)
FV vs -> do
ttys <- mapM (flip (checkLType gr g) typ) vs
--- checkIfComplexVariantType trm typ
return (FV (map fst ttys), typ) --- typ' ?
S tab arg -> checks [ do
(tab',ty) <- inferLType gr g tab
ty' <- computeLType gr g ty
case ty' of
Table p t -> do
(arg',val) <- checkLType gr g arg p
checkEqLType gr g typ t trm
return (S tab' arg', t)
_ -> checkError (text "table type expected for applied table instead of" <+> ppType ty')
, do
(arg',ty) <- inferLType gr g arg
ty' <- computeLType gr g ty
(tab',_) <- checkLType gr g tab (Table ty' typ)
return (S tab' arg', typ)
]
Let (x,(mty,def)) body -> case mty of
Just ty -> do
(def',ty') <- checkLType gr g def ty
body' <- justCheck ((Explicit,x,ty'):g) body typ
return (Let (x,(Just ty',def')) body', typ)
_ -> do
(def',ty) <- inferLType gr g def -- tries to infer type of local constant
checkLType gr g (Let (x,(Just ty,def')) body) typ
ELin c tr -> do
tr1 <- checkErr $ unlockRecord c tr
checkLType gr g tr1 typ
_ -> do
(trm',ty') <- inferLType gr g trm
termWith trm' $ checkEqLType gr g typ ty' trm'
where
justCheck g ty te = checkLType gr g ty te >>= return . fst
recParts rr t = (RecType rr1,RecType rr2) where
(rr1,rr2) = partition (flip elem (map fst t) . fst) rr
checkM rms (l,ty) = case lookup l rms of
Just (Just ty0,t) -> do
checkEqLType gr g ty ty0 t
(t',ty') <- checkLType gr g t ty
return (l,(Just ty',t'))
Just (_,t) -> do
(t',ty') <- checkLType gr g t ty
return (l,(Just ty',t'))
_ -> checkError $
if isLockLabel l
then let cat = drop 5 (showIdent (label2ident l))
in ppTerm Unqualified 0 (R rms) <+> text "is not in the lincat of" <+> text cat <>
text "; try wrapping it with lin" <+> text cat
else text "cannot find value for label" <+> ppLabel l <+> text "in" <+> ppTerm Unqualified 0 (R rms)
checkCase arg val (p,t) = do
cont <- pattContext gr g arg p
t' <- justCheck (reverse cont ++ g) t val
return (p,t')
pattContext :: SourceGrammar -> Context -> Type -> Patt -> Check Context
pattContext env g typ p = case p of
PV x -> return [(Explicit,x,typ)]
PP q c ps | q /= cPredef -> do ---- why this /=? AR 6/1/2006
t <- checkErr $ lookupResType env q c
let (cont,v) = typeFormCnc t
checkCond (text "wrong number of arguments for constructor in" <+> ppPatt Unqualified 0 p)
(length cont == length ps)
checkEqLType env g typ v (patt2term p)
mapM (\((_,_,ty),p) -> pattContext env g ty p) (zip cont ps) >>= return . concat
PR r -> do
typ' <- computeLType env g typ
case typ' of
RecType t -> do
let pts = [(ty,tr) | (l,tr) <- r, Just ty <- [lookup l t]]
----- checkWarn $ prt p ++++ show pts ----- debug
mapM (uncurry (pattContext env g)) pts >>= return . concat
_ -> checkError (text "record type expected for pattern instead of" <+> ppTerm Unqualified 0 typ')
PT t p' -> do
checkEqLType env g typ t (patt2term p')
pattContext env g typ p'
PAs x p -> do
g' <- pattContext env g typ p
return ((Explicit,x,typ):g')
PAlt p' q -> do
g1 <- pattContext env g typ p'
g2 <- pattContext env g typ q
let pts = nub ([x | pt@(_,x,_) <- g1, notElem pt g2] ++ [x | pt@(_,x,_) <- g2, notElem pt g1])
checkCond
(text "incompatible bindings of" <+>
fsep (map ppIdent pts) <+>
text "in pattern alterantives" <+> ppPatt Unqualified 0 p) (null pts)
return g1 -- must be g1 == g2
PSeq p q -> do
g1 <- pattContext env g typ p
g2 <- pattContext env g typ q
return $ g1 ++ g2
PRep p' -> noBind typeStr p'
PNeg p' -> noBind typ p'
_ -> return [] ---- check types!
where
noBind typ p' = do
co <- pattContext env g typ p'
if not (null co)
then checkWarn (text "no variable bound inside pattern" <+> ppPatt Unqualified 0 p)
>> return []
else return []
-- auxiliaries
termWith :: Term -> Check Type -> Check (Term, Type)
termWith t ct = do
ty <- ct
return (t,ty)
-- | light-weight substitution for dep. types
substituteLType :: Context -> Type -> Check Type
substituteLType g t = case t of
Vr x -> return $ maybe t id $ lookup x [(x,t) | (_,x,t) <- g]
_ -> composOp (substituteLType g) t
-- | compositional check\/infer of binary operations
check2 :: (Term -> Check Term) -> (Term -> Term -> Term) ->
Term -> Term -> Type -> Check (Term,Type)
check2 chk con a b t = do
a' <- chk a
b' <- chk b
return (con a' b', t)
checkEqLType :: SourceGrammar -> Context -> Type -> Type -> Term -> Check Type
checkEqLType gr g t u trm = do
(b,t',u',s) <- checkIfEqLType gr g t u trm
case b of
True -> return t'
False -> checkError $ text s <+> text "type of" <+> ppTerm Unqualified 0 trm $$
text "expected:" <+> ppType t $$
text "inferred:" <+> ppType u
checkIfEqLType :: SourceGrammar -> Context -> Type -> Type -> Term -> Check (Bool,Type,Type,String)
checkIfEqLType gr g t u trm = do
t' <- computeLType gr g t
u' <- computeLType gr g u
case t' == u' || alpha [] t' u' of
True -> return (True,t',u',[])
-- forgive missing lock fields by only generating a warning.
--- better: use a flag to forgive? (AR 31/1/2006)
_ -> case missingLock [] t' u' of
Ok lo -> do
checkWarn $ text "missing lock field" <+> fsep (map ppLabel lo)
return (True,t',u',[])
Bad s -> return (False,t',u',s)
where
-- t is a subtype of u
--- quick hack version of TC.eqVal
alpha g t u = case (t,u) of
-- error (the empty type!) is subtype of any other type
(_,u) | u == typeError -> True
-- contravariance
(Prod _ x a b, Prod _ y c d) -> alpha g c a && alpha ((x,y):g) b d
-- record subtyping
(RecType rs, RecType ts) -> all (\ (l,a) ->
any (\ (k,b) -> alpha g a b && l == k) ts) rs
(ExtR r s, ExtR r' s') -> alpha g r r' && alpha g s s'
(ExtR r s, t) -> alpha g r t || alpha g s t
-- the following say that Ints n is a subset of Int and of Ints m >= n
(t,u) | Just m <- isTypeInts t, Just n <- isTypeInts t -> m >= n
| Just _ <- isTypeInts t, u == typeInt -> True ---- check size!
| t == typeInt, Just _ <- isTypeInts u -> True ---- why this ???? AR 11/12/2005
---- this should be made in Rename
(Q m a, Q n b) | a == b -> elem m (allExtendsPlus gr n)
|| elem n (allExtendsPlus gr m)
|| m == n --- for Predef
(QC m a, QC n b) | a == b -> elem m (allExtendsPlus gr n)
|| elem n (allExtendsPlus gr m)
(QC m a, Q n b) | a == b -> elem m (allExtendsPlus gr n)
|| elem n (allExtendsPlus gr m)
(Q m a, QC n b) | a == b -> elem m (allExtendsPlus gr n)
|| elem n (allExtendsPlus gr m)
(Table a b, Table c d) -> alpha g a c && alpha g b d
(Vr x, Vr y) -> x == y || elem (x,y) g || elem (y,x) g
_ -> t == u
--- the following should be one-way coercions only. AR 4/1/2001
|| elem t sTypes && elem u sTypes
|| (t == typeType && u == typePType)
|| (u == typeType && t == typePType)
missingLock g t u = case (t,u) of
(RecType rs, RecType ts) ->
let
ls = [l | (l,a) <- rs,
not (any (\ (k,b) -> alpha g a b && l == k) ts)]
(locks,others) = partition isLockLabel ls
in case others of
_:_ -> Bad $ render (text "missing record fields:" <+> fsep (punctuate comma (map ppLabel others)))
_ -> return locks
-- contravariance
(Prod _ x a b, Prod _ y c d) -> do
ls1 <- missingLock g c a
ls2 <- missingLock g b d
return $ ls1 ++ ls2
_ -> Bad ""
sTypes = [typeStr, typeTok, typeString]
-- printing a type with a lock field lock_C as C
ppType :: Type -> Doc
ppType ty =
case ty of
RecType fs -> case filter isLockLabel $ map fst fs of
[lock] -> text (drop 5 (showIdent (label2ident lock)))
_ -> ppTerm Unqualified 0 ty
Prod _ x a b -> ppType a <+> text "->" <+> ppType b
_ -> ppTerm Unqualified 0 ty
-- | linearization types and defaults
linTypeOfType :: SourceGrammar -> Ident -> Type -> Check (Context,Type)
linTypeOfType cnc m typ = do
let (cont,cat) = typeSkeleton typ
val <- lookLin cat
args <- mapM mkLinArg (zip [0..] cont)
return (args, val)
where
mkLinArg (i,(n,mc@(m,cat))) = do
val <- lookLin mc
let vars = mkRecType varLabel $ replicate n typeStr
symb = argIdent n cat i
rec <- if n==0 then return val else
checkErr $ errIn (render (text "extending" $$
nest 2 (ppTerm Unqualified 0 vars) $$
text "with" $$
nest 2 (ppTerm Unqualified 0 val))) $
plusRecType vars val
return (Explicit,symb,rec)
lookLin (_,c) = checks [ --- rather: update with defLinType ?
checkErr (lookupLincat cnc m c) >>= computeLType cnc []
,return defLinType
]
-- | dependency check, detecting circularities and returning topo-sorted list
allOperDependencies :: Ident -> BinTree Ident Info -> [(Ident,[Ident])]
allOperDependencies m = allDependencies (==m)
allDependencies :: (Ident -> Bool) -> BinTree Ident Info -> [(Ident,[Ident])]
allDependencies ism b =
[(f, nub (concatMap opty (pts i))) | (f,i) <- tree2list b]
where
opersIn t = case t of
Q n c | ism n -> [c]
QC n c | ism n -> [c]
_ -> collectOp opersIn t
opty (Just ty) = opersIn ty
opty _ = []
pts i = case i of
ResOper pty pt -> [pty,pt]
ResParam (Just (ps,_)) -> [Just t | (_,cont) <- ps, (_,_,t) <- cont]
CncCat pty _ _ -> [pty]
CncFun _ pt _ -> [pt] ---- (Maybe (Ident,(Context,Type))
AbsFun pty _ ptr -> [pty] --- ptr is def, which can be mutual
AbsCat (Just co) _ -> [Just ty | (_,_,ty) <- co]
_ -> []
topoSortOpers :: [(Ident,[Ident])] -> Err [Ident]
topoSortOpers st = do
let eops = topoTest st
either
return
(\ops -> Bad (render (text "circular definitions:" <+> fsep (map ppIdent (head ops)))))
eops
checkLookup :: Ident -> Context -> Check Type
checkLookup x g =
case [ty | (b,y,ty) <- g, x == y] of
[] -> checkError (text "unknown variable" <+> ppIdent x)
(ty:_) -> return ty