TyThing(..), TcTyThing(..), TcId,
-- Instance environment, and InstInfo type
- InstInfo(..), pprInstInfo, pprInstInfoDetails,
- simpleInstInfoTy, simpleInstInfoTyCon,
+ InstInfo(..), iDFunId, pprInstInfo, pprInstInfoDetails,
+ simpleInstInfoClsTy, simpleInstInfoTy, simpleInstInfoTyCon,
InstBindings(..),
-- Global environment
tcLookupLocatedClass,
-- Local environment
- tcExtendKindEnv,
+ tcExtendKindEnv, tcExtendKindEnvTvs,
tcExtendTyVarEnv, tcExtendTyVarEnv2,
tcExtendIdEnv, tcExtendIdEnv1, tcExtendIdEnv2,
- tcLookup, tcLookupLocated, tcLookupLocalIds,
- tcLookupId, tcLookupTyVar,
+ tcLookup, tcLookupLocated, tcLookupLocalIds, tcLookupLocalId_maybe,
+ tcLookupId, tcLookupTyVar, getScopedTyVarBinds,
lclEnvElts, getInLocalScope, findGlobals,
- wrongThingErr,
+ wrongThingErr, pprBinders,
+ refineEnvironment,
tcExtendRecEnv, -- For knot-tying
checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel,
topIdLvl,
- -- Arrow stuff
- checkProcLevel,
-
-- New Ids
newLocalName, newDFunName
) where
#include "HsVersions.h"
-import HsSyn ( LRuleDecl, LHsBinds, LSig, pprLHsBinds )
+import HsSyn ( LRuleDecl, LHsBinds, LSig,
+ LHsTyVarBndr, HsTyVarBndr(..), pprLHsBinds )
import TcIface ( tcImportDecl )
+import IfaceEnv ( newGlobalBinder )
import TcRnMonad
-import TcMType ( zonkTcType, zonkTcTyVar, zonkTcTyVarsAndFV )
-import TcType ( Type, TcKind, TcTyVar, TcTyVarSet, TcType,
- tyVarsOfType, tyVarsOfTypes, tcSplitDFunTy, mkGenTyConApp,
+import TcMType ( zonkTcType, zonkTcTyVarsAndFV )
+import TcType ( Type, TcKind, TcTyVar, TcTyVarSet, TcType, TvSubst,
+ substTy, substTyVar, tyVarsOfType, tcTyVarsOfTypes, mkTyConApp,
getDFunTyKey, tcTyConAppTyCon, tcGetTyVar, mkTyVarTy,
- tidyOpenType, tidyOpenTyVar, pprTyThingCategory
+ tidyOpenType, isRefineableTy
)
import qualified Type ( getTyVar_maybe )
-import Id ( idName, isLocalId )
-import Var ( TyVar, Id, idType )
+import Id ( idName, isLocalId, setIdType )
+import Var ( TyVar, Id, idType, tyVarName )
import VarSet
import VarEnv
import RdrName ( extendLocalRdrEnv )
+import InstEnv ( Instance, DFunId, instanceDFunId, instanceHead )
import DataCon ( DataCon )
import TyCon ( TyCon )
import Class ( Class )
-import Name ( Name, NamedThing(..), getSrcLoc, mkInternalName, nameIsLocalOrFrom )
+import Name ( Name, NamedThing(..), getSrcLoc, nameModule, isExternalName )
+import PrelNames ( thFAKE )
import NameEnv
import OccName ( mkDFunOcc, occNameString )
-import HscTypes ( DFunId, extendTypeEnvList, lookupType,
+import HscTypes ( extendTypeEnvList, lookupType,
TyThing(..), tyThingId, tyThingDataCon,
ExternalPackageState(..) )
= addLocM tcLookupGlobal name
tcLookupGlobal :: Name -> TcM TyThing
+-- The Name is almost always an ExternalName, but not always
+-- In GHCi, we may make command-line bindings (ghci> let x = True)
+-- that bind a GlobalId, but with an InternalName
tcLookupGlobal name
= do { env <- getGblEnv
- ; if nameIsLocalOrFrom (tcg_mod env) name
-
- then -- It's defined in this module
- case lookupNameEnv (tcg_type_env env) name of
- Just thing -> return thing
- Nothing -> notFound name -- Panic!
+
+ -- Try local envt
+ ; case lookupNameEnv (tcg_type_env env) name of {
+ Just thing -> return thing ;
+ Nothing -> do
- else do -- It's imported
+ -- Try global envt
{ (eps,hpt) <- getEpsAndHpt
- ; case lookupType hpt (eps_PTE eps) name of
- Just thing -> return thing
- Nothing -> do { traceIf (text "tcLookupGlobal" <+> ppr name)
- ; initIfaceTcRn (tcImportDecl name) }
- }}
-\end{code}
+ ; case lookupType hpt (eps_PTE eps) name of {
+ Just thing -> return thing ;
+ Nothing -> do
+
+ -- Should it have been in the local envt?
+ { let mod = nameModule name
+ ; if mod == tcg_mod env || mod == thFAKE then
+ notFound name -- It should be local, so panic
+ -- The thFAKE possibility is because it
+ -- might be in a declaration bracket
+ else
+ tcImportDecl name -- Go find it in an interface
+ }}}}}
-\begin{code}
tcLookupGlobalId :: Name -> TcM Id
-- Never used for Haskell-source DataCons, hence no ADataCon case
tcLookupGlobalId name
tcLookupTyVar name
= tcLookup name `thenM` \ thing ->
case thing of
- ATyVar _ ty -> returnM (tcGetTyVar "tcLookupTyVar" ty)
+ ATyVar _ ty -> return (tcGetTyVar "tcLookupTyVar" ty)
other -> pprPanic "tcLookupTyVar" (ppr name)
tcLookupId :: Name -> TcM Id
AGlobal (AnId id) -> returnM id
other -> pprPanic "tcLookupId" (ppr name)
+tcLookupLocalId_maybe :: Name -> TcM (Maybe Id)
+tcLookupLocalId_maybe name
+ = getLclEnv `thenM` \ local_env ->
+ case lookupNameEnv (tcl_env local_env) name of
+ Just (ATcId tc_id _ _) -> return (Just tc_id)
+ other -> return Nothing
+
tcLookupLocalIds :: [Name] -> TcM [TcId]
-- We expect the variables to all be bound, and all at
-- the same level as the lookup. Only used in one place...
upd lcl_env = lcl_env { tcl_env = extend (tcl_env lcl_env) }
extend env = extendNameEnvList env [(n, AThing k) | (n,k) <- things]
+tcExtendKindEnvTvs :: [LHsTyVarBndr Name] -> TcM r -> TcM r
+tcExtendKindEnvTvs bndrs thing_inside
+ = updLclEnv upd thing_inside
+ where
+ upd lcl_env = lcl_env { tcl_env = extend (tcl_env lcl_env) }
+ extend env = extendNameEnvList env pairs
+ pairs = [(n, AThing k) | L _ (KindedTyVar n k) <- bndrs]
+
tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r
tcExtendTyVarEnv tvs thing_inside
- = tc_extend_tv_env [ATyVar tv (mkTyVarTy tv) | tv <- tvs] thing_inside
+ = tcExtendTyVarEnv2 [(tyVarName tv, mkTyVarTy tv) | tv <- tvs] thing_inside
-tcExtendTyVarEnv2 :: [(TyVar,TcType)] -> TcM r -> TcM r
-tcExtendTyVarEnv2 ty_pairs thing_inside
- = tc_extend_tv_env [ATyVar tv1 ty2 | (tv1,ty2) <- ty_pairs] thing_inside
-
-tc_extend_tv_env binds thing_inside
+tcExtendTyVarEnv2 :: [(Name,TcType)] -> TcM r -> TcM r
+tcExtendTyVarEnv2 binds thing_inside
= getLclEnv `thenM` \ env@(TcLclEnv {tcl_env = le,
tcl_tyvars = gtvs,
tcl_rdr = rdr_env}) ->
let
- names = [getName tv | ATyVar tv _ <- binds]
- rdr_env' = extendLocalRdrEnv rdr_env names
- le' = extendNameEnvList le (names `zip` binds)
- new_tv_set = tyVarsOfTypes [ty | ATyVar _ ty <- binds]
+ rdr_env' = extendLocalRdrEnv rdr_env (map fst binds)
+ new_tv_set = tcTyVarsOfTypes (map snd binds)
+ le' = extendNameEnvList le [(name, ATyVar name ty) | (name, ty) <- binds]
in
-- It's important to add the in-scope tyvars to the global tyvar set
-- as well. Consider
-- when typechecking the methods.
tc_extend_gtvs gtvs new_tv_set `thenM` \ gtvs' ->
setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside
+
+getScopedTyVarBinds :: TcM [(Name, TcType)]
+getScopedTyVarBinds
+ = do { lcl_env <- getLclEnv
+ ; return [(name, ty) | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)] }
\end{code}
tcExtendIdEnv2 names_w_ids thing_inside
= getLclEnv `thenM` \ env ->
let
- extra_global_tyvars = tyVarsOfTypes [idType id | (name,id) <- names_w_ids]
- th_lvl = thLevel (tcl_th_ctxt env)
- proc_lvl = proc_level (tcl_arrow_ctxt env)
- extra_env = [(name, ATcId id th_lvl proc_lvl) | (name,id) <- names_w_ids]
+ extra_global_tyvars = tcTyVarsOfTypes [idType id | (_,id) <- names_w_ids]
+ th_lvl = thLevel (tcl_th_ctxt env)
+ extra_env = [ (name, ATcId id th_lvl (isRefineableTy (idType id)))
+ | (name,id) <- names_w_ids]
le' = extendNameEnvList (tcl_env env) extra_env
- rdr_env' = extendLocalRdrEnv (tcl_rdr env) (map fst names_w_ids)
+ rdr_env' = extendLocalRdrEnv (tcl_rdr env) [name | (name,_) <- names_w_ids]
in
+ traceTc (text "env2") `thenM_`
+ traceTc (text "env3" <+> ppr extra_env) `thenM_`
tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' ->
- setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside
+ (traceTc (text "env4") `thenM_`
+ setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside)
\end{code}
if ignore_it tv_ty then
returnM (tidy_env, Nothing)
else let
- (tidy_env1, tv1) = tidyOpenTyVar tidy_env tv
- (tidy_env2, tidy_ty) = tidyOpenType tidy_env1 tv_ty
- msg = sep [ppr tv1 <+> eq_stuff, nest 2 bound_at]
+ -- The name tv is scoped, so we don't need to tidy it
+ (tidy_env1, tidy_ty) = tidyOpenType tidy_env tv_ty
+ msg = sep [ptext SLIT("Scoped type variable") <+> quotes (ppr tv) <+> eq_stuff, nest 2 bound_at]
eq_stuff | Just tv' <- Type.getTyVar_maybe tv_ty,
- tv == tv' = empty
+ getOccName tv == getOccName tv' = empty
| otherwise = equals <+> ppr tidy_ty
-- It's ok to use Type.getTyVar_maybe because ty is zonked by now
- bound_at = ptext SLIT("bound at:") <+> ppr (getSrcLoc tv)
+ bound_at = parens $ ptext SLIT("bound at:") <+> ppr (getSrcLoc tv)
in
- returnM (tidy_env2, Just msg)
+ returnM (tidy_env1, Just msg)
\end{code}
+\begin{code}
+refineEnvironment :: TvSubst -> TcM a -> TcM a
+refineEnvironment reft thing_inside
+ = do { env <- getLclEnv
+ ; let le' = mapNameEnv refine (tcl_env env)
+ ; gtvs' <- refineGlobalTyVars reft (tcl_tyvars env)
+ ; setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs'}) thing_inside }
+ where
+ refine (ATcId id lvl True) = ATcId (setIdType id (substTy reft (idType id))) lvl True
+ refine (ATyVar tv ty) = ATyVar tv (substTy reft ty)
+ refine elt = elt
+\end{code}
%************************************************************************
%* *
tc_extend_gtvs gtvs extra_global_tvs
= readMutVar gtvs `thenM` \ global_tvs ->
newMutVar (global_tvs `unionVarSet` extra_global_tvs)
+
+refineGlobalTyVars :: GadtRefinement -> TcRef TcTyVarSet -> TcM (TcRef TcTyVarSet)
+refineGlobalTyVars reft gtv_var
+ = readMutVar gtv_var `thenM` \ gbl_tvs ->
+ newMutVar (tcTyVarsOfTypes (map (substTyVar reft) (varSetElems gbl_tvs)))
\end{code}
@tcGetGlobalTyVars@ returns a fully-zonked set of tyvars free in the environment.
%************************************************************************
%* *
- Arrow notation proc levels
-%* *
-%************************************************************************
-
-\begin{code}
-checkProcLevel :: TcId -> ProcLevel -> TcM ()
-checkProcLevel id id_lvl
- = do { banned <- getBannedProcLevels
- ; checkTc (not (id_lvl `elem` banned))
- (procLevelErr id id_lvl) }
-
-procLevelErr id id_lvl
- = hang (ptext SLIT("Command-bound variable") <+> quotes (ppr id) <+> ptext SLIT("is not in scope here"))
- 4 (ptext SLIT("Reason: it is used in the left argument of (-<)"))
-\end{code}
-
-
-%************************************************************************
-%* *
Meta level
%* *
%************************************************************************
topIdLvl :: Id -> ThLevel
-- Globals may either be imported, or may be from an earlier "chunk"
-- (separated by declaration splices) of this module. The former
--- *can* be used inside a top-level splice, but the latter cannot.
+-- *can* be used inside a top-level splice, but the latter cannot.
-- Hence we give the former impLevel, but the latter topLevel
-- E.g. this is bad:
-- x = [| foo |]
-- E.g. given the name "Expr" return the type "Expr"
tcMetaTy tc_name
= tcLookupTyCon tc_name `thenM` \ t ->
- returnM (mkGenTyConApp t [])
- -- Use mkGenTyConApp because it might be a synonym
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{Making new Ids}
-%* *
-%************************************************************************
-
-Constructing new Ids
-
-\begin{code}
-newLocalName :: Name -> TcM Name
-newLocalName name -- Make a clone
- = newUnique `thenM` \ uniq ->
- returnM (mkInternalName uniq (getOccName name) (getSrcLoc name))
-\end{code}
-
-Make a name for the dict fun for an instance decl. It's a *local*
-name for the moment. The CoreTidy pass will externalise it. Even in
---make and ghci stuff, we rebuild the instance environment each time,
-so the dfun id is internal to begin with, and external when compiling
-other modules
-
-\begin{code}
-newDFunName :: Class -> [Type] -> SrcLoc -> TcM Name
-newDFunName clas (ty:_) loc
- = newUnique `thenM` \ uniq ->
- returnM (mkInternalName uniq (mkDFunOcc dfun_string) loc)
- where
- -- Any string that is somewhat unique will do
- dfun_string = occNameString (getOccName clas) ++ occNameString (getDFunTyKey ty)
-
-newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc)
+ returnM (mkTyConApp t [])
\end{code}
\begin{code}
data InstInfo
= InstInfo {
- iDFunId :: DFunId, -- The dfun id. Its forall'd type variables
- iBinds :: InstBindings -- scope over the stuff in InstBindings!
+ iSpec :: Instance, -- Includes the dfun id. Its forall'd type
+ iBinds :: InstBindings -- variables scope over the stuff in InstBindings!
}
+iDFunId :: InstInfo -> DFunId
+iDFunId info = instanceDFunId (iSpec info)
+
data InstBindings
= VanillaInst -- The normal case
(LHsBinds Name) -- Bindings
details (VanillaInst b _) = pprLHsBinds b
details (NewTypeDerived _) = text "Derived from the representation type"
+simpleInstInfoClsTy :: InstInfo -> (Class, Type)
+simpleInstInfoClsTy info = case instanceHead (iSpec info) of
+ (_, _, cls, [ty]) -> (cls, ty)
+
simpleInstInfoTy :: InstInfo -> Type
-simpleInstInfoTy info = case tcSplitDFunTy (idType (iDFunId info)) of
- (_, _, _, [ty]) -> ty
+simpleInstInfoTy info = snd (simpleInstInfoClsTy info)
simpleInstInfoTyCon :: InstInfo -> TyCon
-- Gets the type constructor for a simple instance declaration,
simpleInstInfoTyCon inst = tcTyConAppTyCon (simpleInstInfoTy inst)
\end{code}
+Make a name for the dict fun for an instance decl. It's an *external*
+name, like otber top-level names, and hence must be made with newGlobalBinder.
+
+\begin{code}
+newDFunName :: Class -> [Type] -> SrcLoc -> TcM Name
+newDFunName clas (ty:_) loc
+ = do { index <- nextDFunIndex
+ ; is_boot <- tcIsHsBoot
+ ; mod <- getModule
+ ; let info_string = occNameString (getOccName clas) ++
+ occNameString (getDFunTyKey ty)
+ dfun_occ = mkDFunOcc info_string is_boot index
+
+ ; newGlobalBinder mod dfun_occ Nothing loc }
+
+newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc)
+\end{code}
+
%************************************************************************
%* *
%************************************************************************
\begin{code}
+pprBinders :: [Name] -> SDoc
+-- Used in error messages
+-- Use quotes for a single one; they look a bit "busy" for several
+pprBinders [bndr] = quotes (ppr bndr)
+pprBinders bndrs = pprWithCommas ppr bndrs
+
notFound name
= failWithTc (ptext SLIT("GHC internal error:") <+> quotes (ppr name) <+>
ptext SLIT("is not in scope"))
wrongThingErr expected thing name
- = failWithTc (pp_thing thing <+> quotes (ppr name) <+>
+ = failWithTc (pprTcTyThingCategory thing <+> quotes (ppr name) <+>
ptext SLIT("used as a") <+> text expected)
- where
- pp_thing (AGlobal thing) = pprTyThingCategory thing
- pp_thing (ATyVar _ _) = ptext SLIT("Type variable")
- pp_thing (ATcId _ _ _) = ptext SLIT("Local identifier")
\end{code}