\begin{code}
+#include "HsVersions.h"
+
module TcType (
- TcTyVar(..),
+ SYN_IE(TcTyVar),
newTcTyVar,
newTyVarTy, -- Kind -> NF_TcM s (TcType s)
newTyVarTys, -- Int -> Kind -> NF_TcM s [TcType s]
- TcTyVarSet(..),
+ SYN_IE(TcTyVarSet),
-----------------------------------------
- TcType(..), TcMaybe(..),
- TcTauType(..), TcThetaType(..), TcRhoType(..),
+ SYN_IE(TcType), TcMaybe(..),
+ SYN_IE(TcTauType), SYN_IE(TcThetaType), SYN_IE(TcRhoType),
-- Find the type to which a type variable is bound
tcWriteTyVar, -- :: TcTyVar s -> TcType s -> NF_TcM (TcType s)
tcReadTyVar, -- :: TcTyVar s -> NF_TcM (TcMaybe s)
- tcInstTyVars, -- TyVar -> NF_TcM s (TcTyVar s)
+ tcInstTyVars,
tcInstSigTyVars,
- tcInstType, tcInstTcType, tcInstTheta,
+ tcInstType, tcInstSigType, tcInstTcType, tcInstSigTcType,
+ tcInstTheta, tcInstId,
- zonkTcTyVars, -- TcTyVarSet s -> NF_TcM s (TcTyVarSet s)
- zonkTcType, -- TcType s -> NF_TcM s (TcType s)
- zonkTcTypeToType, -- TcType s -> NF_TcM s Type
- zonkTcTyVarToTyVar -- TcTyVar s -> NF_TcM s TyVar
+ zonkTcTyVars,
+ zonkTcType,
+ zonkTcTypeToType,
+ zonkTcTyVar,
+ zonkTcTyVarToTyVar
) where
-- friends:
-import Type ( Type(..), ThetaType(..), GenType(..), tyVarsOfTypes, getTyVar_maybe )
-import TyVar ( TyVar(..), GenTyVar(..), TyVarSet(..), GenTyVarSet(..),
+import Type ( SYN_IE(Type), SYN_IE(ThetaType), GenType(..),
+ tyVarsOfTypes, getTyVar_maybe,
+ splitForAllTy, splitRhoTy,
+ mkForAllTys, instantiateTy
+ )
+import TyVar ( SYN_IE(TyVar), GenTyVar(..), SYN_IE(TyVarSet), SYN_IE(GenTyVarSet),
+ SYN_IE(TyVarEnv), lookupTyVarEnv, addOneToTyVarEnv,
+ nullTyVarEnv, mkTyVarEnv,
tyVarSetToList
)
-- others:
-import Kind ( Kind )
-import Usage ( Usage(..), GenUsage, UVar(..), duffUsage )
import Class ( GenClass )
+import Id ( idType )
+import Kind ( Kind )
import TcKind ( TcKind )
-import TcMonad
+import TcMonad hiding ( rnMtoTcM )
+import Usage ( SYN_IE(Usage), GenUsage, SYN_IE(UVar), duffUsage )
-import Ubiq
+import TysPrim ( voidTy )
+
+IMP_Ubiq()
import Unique ( Unique )
import UniqFM ( UniqFM )
-import Name ( getNameShortName )
import Maybes ( assocMaybe )
-import Util ( panic, pprPanic )
+import Util ( zipEqual, nOfThem, panic{-, pprPanic, pprTrace ToDo:rm-} )
-import Outputable ( Outputable(..) ) -- Debugging messages
-import PprType ( GenTyVar, GenType )
-import Pretty -- ditto
-import PprStyle ( PprStyle(..) ) -- ditto
+--import Outputable ( Outputable(..) ) -- Debugging messages
+--import PprType ( GenTyVar, GenType )
+--import Pretty -- ditto
+--import PprStyle ( PprStyle(..) ) -- ditto
\end{code}
returnNF_Tc (TyVarTy tc_tyvar)
newTyVarTys :: Int -> Kind -> NF_TcM s [TcType s]
-newTyVarTys n kind = mapNF_Tc newTyVarTy (take n (repeat kind))
-
+newTyVarTys n kind = mapNF_Tc newTyVarTy (nOfThem n kind)
-- For signature type variables, mark them as "DontBind"
tcInstTyVars, tcInstSigTyVars
:: [GenTyVar flexi]
-> NF_TcM s ([TcTyVar s], [TcType s], [(GenTyVar flexi, TcType s)])
+
tcInstTyVars tyvars = inst_tyvars UnBound tyvars
tcInstSigTyVars tyvars = inst_tyvars DontBind tyvars
-
inst_tyvars initial_cts tyvars
= mapNF_Tc (inst_tyvar initial_cts) tyvars `thenNF_Tc` \ tc_tyvars ->
let
tys = map TyVarTy tc_tyvars
in
- returnNF_Tc (tc_tyvars, tys, tyvars `zip` tys)
+ returnNF_Tc (tc_tyvars, tys, zipEqual "inst_tyvars" tyvars tys)
inst_tyvar initial_cts (TyVar _ kind name _)
= tcGetUnique `thenNF_Tc` \ uniq ->
returnNF_Tc (TyVar uniq kind name box)
\end{code}
-@tcInstType@ and @tcInstTcType@ both create a fresh instance of a
+@tcInstType@ and @tcInstSigType@ both create a fresh instance of a
type, returning a @TcType@. All inner for-alls are instantiated with
fresh TcTyVars.
-There are two versions, one for instantiating a @Type@, and one for a @TcType@.
-The former must instantiate everything; all tyvars must be bound either
-by a forall or by an environment passed in. The latter can do some sharing,
-and is happy with free tyvars (which is vital when instantiating the type
-of local functions). In the future @tcInstType@ may try to be clever about not
-instantiating constant sub-parts.
+The difference is that tcInstType instantiates all forall'd type
+variables (and their bindees) with UnBound type variables, whereas
+tcInstSigType instantiates them with DontBind types variables.
+@tcInstSigType@ also doesn't take an environment.
+
+On the other hand, @tcInstTcType@ instantiates a TcType. It uses
+instantiateTy which could take advantage of sharing some day.
\begin{code}
-tcInstType :: [(TyVar,TcType s)] -> Type -> NF_TcM s (TcType s)
+tcInstTcType :: TcType s -> NF_TcM s ([TcTyVar s], TcType s)
+tcInstTcType ty
+ = case tyvars of
+ [] -> returnNF_Tc ([], ty) -- Nothing to do
+ other -> tcInstTyVars tyvars `thenNF_Tc` \ (tyvars', _, tenv) ->
+ returnNF_Tc (tyvars', instantiateTy tenv rho)
+ where
+ (tyvars, rho) = splitForAllTy ty
+
+tcInstSigTcType :: TcType s -> NF_TcM s ([TcTyVar s], TcType s)
+tcInstSigTcType ty
+ = case tyvars of
+ [] -> returnNF_Tc ([], ty) -- Nothing to do
+ other -> tcInstSigTyVars tyvars `thenNF_Tc` \ (tyvars', _, tenv) ->
+ returnNF_Tc (tyvars', instantiateTy tenv rho)
+ where
+ (tyvars, rho) = splitForAllTy ty
+
+tcInstType :: [(GenTyVar flexi,TcType s)]
+ -> GenType (GenTyVar flexi) UVar
+ -> NF_TcM s (TcType s)
tcInstType tenv ty_to_inst
- = do [(uniq,ty) | (TyVar uniq _ _ _, ty) <- tenv] ty_to_inst
+ = tcConvert bind_fn occ_fn (mkTyVarEnv tenv) ty_to_inst
+ where
+ bind_fn = inst_tyvar UnBound
+ occ_fn env tyvar = case lookupTyVarEnv env tyvar of
+ Just ty -> returnNF_Tc ty
+ Nothing -> panic "tcInstType:1" --(ppAboves [ppr PprDebug ty_to_inst,
+ -- ppr PprDebug tyvar])
+
+tcInstSigType :: GenType (GenTyVar flexi) UVar -> NF_TcM s (TcType s)
+tcInstSigType ty_to_inst
+ = tcConvert bind_fn occ_fn nullTyVarEnv ty_to_inst
+ where
+ bind_fn = inst_tyvar DontBind
+ occ_fn env tyvar = case lookupTyVarEnv env tyvar of
+ Just ty -> returnNF_Tc ty
+ Nothing -> panic "tcInstType:2"-- (ppAboves [ppr PprDebug ty_to_inst,
+ -- ppr PprDebug tyvar])
+
+zonkTcTyVarToTyVar :: TcTyVar s -> NF_TcM s TyVar
+zonkTcTyVarToTyVar tv
+ = zonkTcTyVar tv `thenNF_Tc` \ tv_ty ->
+ case tv_ty of -- Should be a tyvar!
+
+ TyVarTy tv' -> returnNF_Tc (tcTyVarToTyVar tv')
+
+ _ -> --pprTrace "zonkTcTyVarToTyVar:" (ppCat [ppr PprDebug tv, ppr PprDebug tv_ty]) $
+ returnNF_Tc (tcTyVarToTyVar tv)
+
+
+zonkTcTypeToType :: TyVarEnv Type -> TcType s -> NF_TcM s Type
+zonkTcTypeToType env ty
+ = tcConvert zonkTcTyVarToTyVar occ_fn env ty
+ where
+ occ_fn env tyvar
+ = tcReadTyVar tyvar `thenNF_Tc` \ maybe_ty ->
+ case maybe_ty of
+ BoundTo (TyVarTy tyvar') -> lookup env tyvar'
+ BoundTo other_ty -> tcConvert zonkTcTyVarToTyVar occ_fn env other_ty
+ other -> lookup env tyvar
+
+ lookup env tyvar = case lookupTyVarEnv env tyvar of
+ Just ty -> returnNF_Tc ty
+ Nothing -> returnNF_Tc voidTy -- Unbound type variables go to Void
+
+
+tcConvert bind_fn occ_fn env ty_to_convert
+ = doo env ty_to_convert
where
- do env (TyConTy tycon usage) = returnNF_Tc (TyConTy tycon usage)
+ doo env (TyConTy tycon usage) = returnNF_Tc (TyConTy tycon usage)
- do env (SynTy tycon tys ty) = mapNF_Tc (do env) tys `thenNF_Tc` \ tys' ->
- do env ty `thenNF_Tc` \ ty' ->
+ doo env (SynTy tycon tys ty) = mapNF_Tc (doo env) tys `thenNF_Tc` \ tys' ->
+ doo env ty `thenNF_Tc` \ ty' ->
returnNF_Tc (SynTy tycon tys' ty')
- do env (FunTy arg res usage) = do env arg `thenNF_Tc` \ arg' ->
- do env res `thenNF_Tc` \ res' ->
+ doo env (FunTy arg res usage) = doo env arg `thenNF_Tc` \ arg' ->
+ doo env res `thenNF_Tc` \ res' ->
returnNF_Tc (FunTy arg' res' usage)
- do env (AppTy fun arg) = do env fun `thenNF_Tc` \ fun' ->
- do env arg `thenNF_Tc` \ arg' ->
+ doo env (AppTy fun arg) = doo env fun `thenNF_Tc` \ fun' ->
+ doo env arg `thenNF_Tc` \ arg' ->
returnNF_Tc (AppTy fun' arg')
- do env (DictTy clas ty usage)= do env ty `thenNF_Tc` \ ty' ->
+ doo env (DictTy clas ty usage)= doo env ty `thenNF_Tc` \ ty' ->
returnNF_Tc (DictTy clas ty' usage)
- do env (TyVarTy tv@(TyVar uniq kind name _))
- = case assocMaybe env uniq of
- Just tc_ty -> returnNF_Tc tc_ty
- Nothing -> pprPanic "tcInstType:" (ppAboves [ppr PprDebug tenv,
- ppr PprDebug ty_to_inst, ppr PprDebug tv])
+ doo env (ForAllUsageTy u us ty) = doo env ty `thenNF_Tc` \ ty' ->
+ returnNF_Tc (ForAllUsageTy u us ty')
+
+ -- The two interesting cases!
+ doo env (TyVarTy tv) = occ_fn env tv
- do env (ForAllTy tyvar@(TyVar uniq kind name _) ty)
- = inst_tyvar DontBind tyvar `thenNF_Tc` \ tc_tyvar ->
+ doo env (ForAllTy tyvar ty)
+ = bind_fn tyvar `thenNF_Tc` \ tyvar' ->
let
- new_env = (uniq, TyVarTy tc_tyvar) : env
+ new_env = addOneToTyVarEnv env tyvar (TyVarTy tyvar')
in
- do new_env ty `thenNF_Tc` \ ty' ->
- returnNF_Tc (ForAllTy tc_tyvar ty')
-
- -- ForAllUsage impossible
+ doo new_env ty `thenNF_Tc` \ ty' ->
+ returnNF_Tc (ForAllTy tyvar' ty')
tcInstTheta :: [(TyVar,TcType s)] -> ThetaType -> NF_TcM s (TcThetaType s)
go (clas,ty) = tcInstType tenv ty `thenNF_Tc` \ tc_ty ->
returnNF_Tc (clas, tc_ty)
---???tcSpecTy :: Type -> NF_TcM s (
-
-tcInstTcType :: [(TcTyVar s,TcType s)] -> TcType s -> NF_TcM s (TcType s)
-tcInstTcType tenv ty_to_inst
- = do [(uniq,ty) | (TyVar uniq _ _ _, ty) <- tenv] ty_to_inst
- where
- do env ty@(TyConTy tycon usage) = returnNF_Tc ty
-
--- Could do clever stuff here to avoid instantiating constant types
- do env (SynTy tycon tys ty) = mapNF_Tc (do env) tys `thenNF_Tc` \ tys' ->
- do env ty `thenNF_Tc` \ ty' ->
- returnNF_Tc (SynTy tycon tys' ty')
-
- do env (FunTy arg res usage) = do env arg `thenNF_Tc` \ arg' ->
- do env res `thenNF_Tc` \ res' ->
- returnNF_Tc (FunTy arg' res' usage)
-
- do env (AppTy fun arg) = do env fun `thenNF_Tc` \ fun' ->
- do env arg `thenNF_Tc` \ arg' ->
- returnNF_Tc (AppTy fun' arg')
-
- do env (DictTy clas ty usage)= do env ty `thenNF_Tc` \ ty' ->
- returnNF_Tc (DictTy clas ty' usage)
-
- do env ty@(TyVarTy (TyVar uniq kind name _))
- = case assocMaybe env uniq of
- Just tc_ty -> returnNF_Tc tc_ty
- Nothing -> returnNF_Tc ty
-
- do env (ForAllTy (TyVar uniq kind name _) ty) = panic "tcInstTcType"
-
- -- ForAllUsage impossible
+-- A useful function that takes an occurrence of a global thing
+-- and instantiates its type with fresh type variables
+tcInstId :: Id
+ -> NF_TcM s ([TcTyVar s], -- It's instantiated type
+ TcThetaType s, --
+ TcType s) --
+tcInstId id
+ = let
+ (tyvars, rho) = splitForAllTy (idType id)
+ in
+ tcInstTyVars tyvars `thenNF_Tc` \ (tyvars', arg_tys, tenv) ->
+ tcInstType tenv rho `thenNF_Tc` \ rho' ->
+ let
+ (theta', tau') = splitRhoTy rho'
+ in
+ returnNF_Tc (tyvars', theta', tau')
\end{code}
Reading and writing TcTyVars
Zonking
~~~~~~~
-@zonkTcTypeToType@ converts from @TcType@ to @Type@. It follows through all
-the substitutions of course.
-
\begin{code}
-zonkTcTypeToType :: TcType s -> NF_TcM s Type
-zonkTcTypeToType ty = zonk tcTyVarToTyVar ty
-
-zonkTcType :: TcType s -> NF_TcM s (TcType s)
-zonkTcType ty = zonk (\tyvar -> tyvar) ty
-
zonkTcTyVars :: TcTyVarSet s -> NF_TcM s (TcTyVarSet s)
zonkTcTyVars tyvars
- = mapNF_Tc (zonk_tv (\tyvar -> tyvar))
- (tyVarSetToList tyvars) `thenNF_Tc` \ tys ->
+ = mapNF_Tc zonkTcTyVar (tyVarSetToList tyvars) `thenNF_Tc` \ tys ->
returnNF_Tc (tyVarsOfTypes tys)
-zonkTcTyVarToTyVar :: TcTyVar s -> NF_TcM s TyVar
-zonkTcTyVarToTyVar tyvar
- = zonk_tv_to_tv tcTyVarToTyVar tyvar
+zonkTcTyVar :: TcTyVar s -> NF_TcM s (TcType s)
+zonkTcTyVar tyvar
+ = tcReadTyVar tyvar `thenNF_Tc` \ maybe_ty ->
+ case maybe_ty of
+ BoundTo ty@(TyVarTy tyvar') -> returnNF_Tc ty
+ BoundTo other -> zonkTcType other
+ other -> returnNF_Tc (TyVarTy tyvar)
+zonkTcType :: TcType s -> NF_TcM s (TcType s)
-zonk tyvar_fn (TyVarTy tyvar)
- = zonk_tv tyvar_fn tyvar
+zonkTcType (TyVarTy tyvar) = zonkTcTyVar tyvar
-zonk tyvar_fn (AppTy ty1 ty2)
- = zonk tyvar_fn ty1 `thenNF_Tc` \ ty1' ->
- zonk tyvar_fn ty2 `thenNF_Tc` \ ty2' ->
+zonkTcType (AppTy ty1 ty2)
+ = zonkTcType ty1 `thenNF_Tc` \ ty1' ->
+ zonkTcType ty2 `thenNF_Tc` \ ty2' ->
returnNF_Tc (AppTy ty1' ty2')
-zonk tyvar_fn (TyConTy tc u)
+zonkTcType (TyConTy tc u)
= returnNF_Tc (TyConTy tc u)
-zonk tyvar_fn (SynTy tc tys ty)
- = mapNF_Tc (zonk tyvar_fn) tys `thenNF_Tc` \ tys' ->
- zonk tyvar_fn ty `thenNF_Tc` \ ty' ->
+zonkTcType (SynTy tc tys ty)
+ = mapNF_Tc zonkTcType tys `thenNF_Tc` \ tys' ->
+ zonkTcType ty `thenNF_Tc` \ ty' ->
returnNF_Tc (SynTy tc tys' ty')
-zonk tyvar_fn (ForAllTy tv ty)
- = zonk_tv_to_tv tyvar_fn tv `thenNF_Tc` \ tv' ->
- zonk tyvar_fn ty `thenNF_Tc` \ ty' ->
- returnNF_Tc (ForAllTy tv' ty')
-
-zonk tyvar_fn (ForAllUsageTy uv uvs ty)
+zonkTcType (ForAllTy tv ty)
+ = zonkTcTyVar tv `thenNF_Tc` \ tv_ty ->
+ zonkTcType ty `thenNF_Tc` \ ty' ->
+ case tv_ty of -- Should be a tyvar!
+ TyVarTy tv' ->
+ returnNF_Tc (ForAllTy tv' ty')
+ _ -> --pprTrace "zonkTcType:ForAllTy:" (ppCat [ppr PprDebug tv, ppr PprDebug tv_ty]) $
+
+ returnNF_Tc (ForAllTy tv{-(tcTyVarToTyVar tv)-} ty')
+
+zonkTcType (ForAllUsageTy uv uvs ty)
= panic "zonk:ForAllUsageTy"
-zonk tyvar_fn (FunTy ty1 ty2 u)
- = zonk tyvar_fn ty1 `thenNF_Tc` \ ty1' ->
- zonk tyvar_fn ty2 `thenNF_Tc` \ ty2' ->
+zonkTcType (FunTy ty1 ty2 u)
+ = zonkTcType ty1 `thenNF_Tc` \ ty1' ->
+ zonkTcType ty2 `thenNF_Tc` \ ty2' ->
returnNF_Tc (FunTy ty1' ty2' u)
-zonk tyvar_fn (DictTy c ty u)
- = zonk tyvar_fn ty `thenNF_Tc` \ ty' ->
+zonkTcType (DictTy c ty u)
+ = zonkTcType ty `thenNF_Tc` \ ty' ->
returnNF_Tc (DictTy c ty' u)
-
-
-zonk_tv tyvar_fn tyvar
- = tcReadTyVar tyvar `thenNF_Tc` \ maybe_ty ->
- case maybe_ty of
- BoundTo ty -> zonk tyvar_fn ty
- other -> returnNF_Tc (TyVarTy (tyvar_fn tyvar))
-
-
-zonk_tv_to_tv tyvar_fn tyvar
- = zonk_tv tyvar_fn tyvar `thenNF_Tc` \ ty ->
- case getTyVar_maybe ty of
- Nothing -> panic "zonk_tv_to_tv"
- Just tyvar -> returnNF_Tc tyvar
\end{code}
projects / ghc-hetmet.git / blobdiff