tcSyntaxName,
-- Simple functions over evidence variables
- hasEqualities,
+ hasEqualities, unitImplication,
- tyVarsOfWanteds, tyVarsOfWanted, tyVarsOfWantedEvVar, tyVarsOfWantedEvVars,
+ tyVarsOfWC, tyVarsOfBag, tyVarsOfEvVarXs, tyVarsOfEvVarX,
tyVarsOfEvVar, tyVarsOfEvVars, tyVarsOfImplication,
- tidyWanteds, tidyWanted, tidyWantedEvVar, tidyWantedEvVars,
- tidyEvVar, tidyImplication
+ tidyWantedEvVar, tidyWantedEvVars, tidyWC,
+ tidyEvVar, tidyImplication, tidyFlavoredEvVar,
+
+ substWantedEvVar, substWantedEvVars, substFlavoredEvVar,
+ substEvVar, substImplication
) where
#include "HsVersions.h"
import TcType
import Class
import Unify
-import Coercion
import HscTypes
import Id
import Name
import Maybes
import Util
import Outputable
-import Data.List
+import Data.List( mapAccumL )
\end{code}
emitWanted :: CtOrigin -> TcPredType -> TcM EvVar
emitWanted origin pred = do { loc <- getCtLoc origin
; ev <- newWantedEvVar pred
- ; emitConstraint (WcEvVar (WantedEvVar ev loc))
+ ; emitFlat (mkEvVarX ev loc)
; return ev }
newMethodFromName :: CtOrigin -> Name -> TcRhoType -> TcM (HsExpr TcId)
\begin{code}
deeplySkolemise
- :: SkolemInfo
- -> TcSigmaType
+ :: TcSigmaType
-> TcM (HsWrapper, [TyVar], [EvVar], TcRhoType)
-deeplySkolemise skol_info ty
+deeplySkolemise ty
| Just (arg_tys, tvs, theta, ty') <- tcDeepSplitSigmaTy_maybe ty
= do { ids1 <- newSysLocalIds (fsLit "dk") arg_tys
- ; tvs1 <- mapM (tcInstSkolTyVar skol_info) tvs
+ ; tvs1 <- tcInstSkolTyVars tvs
; let subst = zipTopTvSubst tvs (mkTyVarTys tvs1)
; ev_vars1 <- newEvVars (substTheta subst theta)
- ; (wrap, tvs2, ev_vars2, rho) <- deeplySkolemise skol_info (substTy subst ty')
+ ; (wrap, tvs2, ev_vars2, rho) <- deeplySkolemise (substTy subst ty')
; return ( mkWpLams ids1
<.> mkWpTyLams tvs1
<.> mkWpLams ev_vars1
instCallConstraints origin (EqPred ty1 ty2 : preds) -- Try short-cut
= do { traceTc "instCallConstraints" $ ppr (EqPred ty1 ty2)
- ; coi <- unifyType ty1 ty2
+ ; co <- unifyType ty1 ty2
; co_fn <- instCallConstraints origin preds
- ; let co = case coi of
- IdCo ty -> ty
- ACo co -> co
; return (co_fn <.> WpEvApp (EvCoercion co)) }
instCallConstraints origin (pred : preds)
-- This is important because the template variables must
-- not overlap with anything in the things being looked up
-- (since we do unification).
- -- We use tcInstSkolType because we don't want to allocate fresh
- -- *meta* type variables.
+ --
+ -- We use tcInstSkolType because we don't want to allocate fresh
+ -- *meta* type variables.
+ --
+ -- We use UnkSkol --- and *not* InstSkol or PatSkol --- because
+ -- these variables must be bindable by tcUnifyTys. See
+ -- the call to tcUnifyTys in InstEnv, and the special
+ -- treatment that instanceBindFun gives to isOverlappableTyVar
+ -- This is absurdly delicate.
+
let dfun = instanceDFunId ispec
- ; (tvs', theta', tau') <- tcInstSkolType InstSkol (idType dfun)
+ ; (tvs', theta', tau') <- tcInstSkolType (idType dfun)
; let (cls, tys') = tcSplitDFunHead tau'
dfun' = setIdType dfun (mkSigmaTy tvs' theta' tau')
ispec' = setInstanceDFunId ispec dfun'
%************************************************************************
\begin{code}
+unitImplication :: Implication -> Bag Implication
+unitImplication implic
+ | isEmptyWC (ic_wanted implic) = emptyBag
+ | otherwise = unitBag implic
+
hasEqualities :: [EvVar] -> Bool
-- Has a bunch of canonical constraints (all givens) got any equalities in it?
hasEqualities givens = any (has_eq . evVarPred) givens
where
- has_eq (EqPred {}) = True
- has_eq (IParam {}) = False
- has_eq (ClassP cls tys) = any has_eq (substTheta subst (classSCTheta cls))
- where
- subst = zipOpenTvSubst (classTyVars cls) tys
+ has_eq (EqPred {}) = True
+ has_eq (IParam {}) = False
+ has_eq (ClassP cls _tys) = any has_eq (classSCTheta cls)
-----------------
-tyVarsOfWanteds :: WantedConstraints -> TyVarSet
-tyVarsOfWanteds = foldrBag (unionVarSet . tyVarsOfWanted) emptyVarSet
-
-tyVarsOfWanted :: WantedConstraint -> TyVarSet
-tyVarsOfWanted (WcEvVar wev) = tyVarsOfWantedEvVar wev
-tyVarsOfWanted (WcImplic impl) = tyVarsOfImplication impl
+---------------- Getting free tyvars -------------------------
+tyVarsOfWC :: WantedConstraints -> TyVarSet
+tyVarsOfWC (WC { wc_flat = flat, wc_impl = implic, wc_insol = insol })
+ = tyVarsOfEvVarXs flat `unionVarSet`
+ tyVarsOfBag tyVarsOfImplication implic `unionVarSet`
+ tyVarsOfEvVarXs insol
tyVarsOfImplication :: Implication -> TyVarSet
-tyVarsOfImplication implic = tyVarsOfWanteds (ic_wanted implic)
- `minusVarSet` (ic_skols implic)
+tyVarsOfImplication (Implic { ic_skols = skols, ic_wanted = wanted })
+ = tyVarsOfWC wanted `minusVarSet` skols
-tyVarsOfWantedEvVar :: WantedEvVar -> TyVarSet
-tyVarsOfWantedEvVar (WantedEvVar ev _) = tyVarsOfEvVar ev
+tyVarsOfEvVarX :: EvVarX a -> TyVarSet
+tyVarsOfEvVarX (EvVarX ev _) = tyVarsOfEvVar ev
-tyVarsOfWantedEvVars :: Bag WantedEvVar -> TyVarSet
-tyVarsOfWantedEvVars = foldrBag (unionVarSet . tyVarsOfWantedEvVar) emptyVarSet
+tyVarsOfEvVarXs :: Bag (EvVarX a) -> TyVarSet
+tyVarsOfEvVarXs = tyVarsOfBag tyVarsOfEvVarX
tyVarsOfEvVar :: EvVar -> TyVarSet
tyVarsOfEvVar ev = tyVarsOfPred $ evVarPred ev
tyVarsOfEvVars :: [EvVar] -> TyVarSet
tyVarsOfEvVars = foldr (unionVarSet . tyVarsOfEvVar) emptyVarSet
----------------
-tidyWanteds :: TidyEnv -> WantedConstraints -> WantedConstraints
-tidyWanteds env = mapBag (tidyWanted env)
+tyVarsOfBag :: (a -> TyVarSet) -> Bag a -> TyVarSet
+tyVarsOfBag tvs_of = foldrBag (unionVarSet . tvs_of) emptyVarSet
-tidyWanted :: TidyEnv -> WantedConstraint -> WantedConstraint
-tidyWanted env (WcEvVar wev) = WcEvVar (tidyWantedEvVar env wev)
-tidyWanted env (WcImplic implic) = WcImplic (tidyImplication env implic)
+---------------- Tidying -------------------------
+tidyWC :: TidyEnv -> WantedConstraints -> WantedConstraints
+tidyWC env (WC { wc_flat = flat, wc_impl = implic, wc_insol = insol })
+ = WC { wc_flat = tidyWantedEvVars env flat
+ , wc_impl = mapBag (tidyImplication env) implic
+ , wc_insol = mapBag (tidyFlavoredEvVar env) insol }
+
+tidyImplication :: TidyEnv -> Implication -> Implication
+tidyImplication env implic@(Implic { ic_skols = tvs
+ , ic_given = given
+ , ic_wanted = wanted
+ , ic_loc = loc })
+ = implic { ic_skols = mkVarSet tvs'
+ , ic_given = map (tidyEvVar env1) given
+ , ic_wanted = tidyWC env1 wanted
+ , ic_loc = tidyGivenLoc env1 loc }
+ where
+ (env1, tvs') = mapAccumL tidyTyVarBndr env (varSetElems tvs)
+
+tidyEvVar :: TidyEnv -> EvVar -> EvVar
+tidyEvVar env var = setVarType var (tidyType env (varType var))
tidyWantedEvVar :: TidyEnv -> WantedEvVar -> WantedEvVar
-tidyWantedEvVar env (WantedEvVar ev loc) = WantedEvVar (tidyEvVar env ev) loc
+tidyWantedEvVar env (EvVarX v l) = EvVarX (tidyEvVar env v) l
tidyWantedEvVars :: TidyEnv -> Bag WantedEvVar -> Bag WantedEvVar
tidyWantedEvVars env = mapBag (tidyWantedEvVar env)
-tidyEvVar :: TidyEnv -> EvVar -> EvVar
-tidyEvVar env v = setVarType v (tidyType env (varType v))
-
-tidyImplication :: TidyEnv -> Implication -> Implication
-tidyImplication env implic@(Implic { ic_skols = skols, ic_given = given
- , ic_wanted = wanted })
- = implic { ic_skols = mkVarSet skols'
- , ic_given = map (tidyEvVar env') given
- , ic_wanted = tidyWanteds env' wanted }
+tidyFlavoredEvVar :: TidyEnv -> FlavoredEvVar -> FlavoredEvVar
+tidyFlavoredEvVar env (EvVarX v fl)
+ = EvVarX (tidyEvVar env v) (tidyFlavor env fl)
+
+tidyFlavor :: TidyEnv -> CtFlavor -> CtFlavor
+tidyFlavor env (Given loc gk) = Given (tidyGivenLoc env loc) gk
+tidyFlavor _ fl = fl
+
+tidyGivenLoc :: TidyEnv -> GivenLoc -> GivenLoc
+tidyGivenLoc env (CtLoc skol span ctxt) = CtLoc (tidySkolemInfo env skol) span ctxt
+
+tidySkolemInfo :: TidyEnv -> SkolemInfo -> SkolemInfo
+tidySkolemInfo env (SigSkol cx ty) = SigSkol cx (tidyType env ty)
+tidySkolemInfo env (InferSkol ids) = InferSkol (mapSnd (tidyType env) ids)
+tidySkolemInfo _ info = info
+
+---------------- Substitution -------------------------
+substWC :: TvSubst -> WantedConstraints -> WantedConstraints
+substWC subst (WC { wc_flat = flat, wc_impl = implic, wc_insol = insol })
+ = WC { wc_flat = substWantedEvVars subst flat
+ , wc_impl = mapBag (substImplication subst) implic
+ , wc_insol = mapBag (substFlavoredEvVar subst) insol }
+
+substImplication :: TvSubst -> Implication -> Implication
+substImplication subst implic@(Implic { ic_skols = tvs
+ , ic_given = given
+ , ic_wanted = wanted
+ , ic_loc = loc })
+ = implic { ic_skols = mkVarSet tvs'
+ , ic_given = map (substEvVar subst1) given
+ , ic_wanted = substWC subst1 wanted
+ , ic_loc = substGivenLoc subst1 loc }
where
- (env', skols') = mapAccumL tidyTyVarBndr env (varSetElems skols)
-\end{code}
\ No newline at end of file
+ (subst1, tvs') = mapAccumL substTyVarBndr subst (varSetElems tvs)
+
+substEvVar :: TvSubst -> EvVar -> EvVar
+substEvVar subst var = setVarType var (substTy subst (varType var))
+
+substWantedEvVars :: TvSubst -> Bag WantedEvVar -> Bag WantedEvVar
+substWantedEvVars subst = mapBag (substWantedEvVar subst)
+
+substWantedEvVar :: TvSubst -> WantedEvVar -> WantedEvVar
+substWantedEvVar subst (EvVarX v l) = EvVarX (substEvVar subst v) l
+
+substFlavoredEvVar :: TvSubst -> FlavoredEvVar -> FlavoredEvVar
+substFlavoredEvVar subst (EvVarX v fl)
+ = EvVarX (substEvVar subst v) (substFlavor subst fl)
+
+substFlavor :: TvSubst -> CtFlavor -> CtFlavor
+substFlavor subst (Given loc gk) = Given (substGivenLoc subst loc) gk
+substFlavor _ fl = fl
+
+substGivenLoc :: TvSubst -> GivenLoc -> GivenLoc
+substGivenLoc subst (CtLoc skol span ctxt) = CtLoc (substSkolemInfo subst skol) span ctxt
+
+substSkolemInfo :: TvSubst -> SkolemInfo -> SkolemInfo
+substSkolemInfo subst (SigSkol cx ty) = SigSkol cx (substTy subst ty)
+substSkolemInfo subst (InferSkol ids) = InferSkol (mapSnd (substTy subst) ids)
+substSkolemInfo _ info = info
+\end{code}
projects / ghc-hetmet.git / blobdiff