+%
+% (c) The University of Glasgow 2006
+%
+
\begin{code}
module TcEnv(
TyThing(..), TcTyThing(..), TcId,
tcLookupLocatedGlobal, tcLookupGlobal,
tcLookupField, tcLookupTyCon, tcLookupClass, tcLookupDataCon,
tcLookupLocatedGlobalId, tcLookupLocatedTyCon,
- tcLookupLocatedClass,
+ tcLookupLocatedClass, tcLookupFamInst,
-- Local environment
tcExtendKindEnv, tcExtendKindEnvTvs,
tcExtendTyVarEnv, tcExtendTyVarEnv2,
tcExtendIdEnv, tcExtendIdEnv1, tcExtendIdEnv2,
- tcLookup, tcLookupLocated, tcLookupLocalIds, tcLookupLocalId_maybe,
+ tcLookup, tcLookupLocated, tcLookupLocalIds,
tcLookupId, tcLookupTyVar, getScopedTyVarBinds,
lclEnvElts, getInLocalScope, findGlobals,
wrongThingErr, pprBinders,
topIdLvl,
-- New Ids
- newLocalName, newDFunName
+ newLocalName, newDFunName, newFamInstTyConName
) where
#include "HsVersions.h"
-import HsSyn ( LRuleDecl, LHsBinds, LSig,
- LHsTyVarBndr, HsTyVarBndr(..), pprLHsBinds )
-import TcIface ( tcImportDecl )
-import IfaceEnv ( newGlobalBinder )
+import HsSyn
+import TcIface
+import IfaceEnv
import TcRnMonad
-import TcMType ( zonkTcType, zonkTcTyVarsAndFV )
-import TcType ( Type, TcKind, TcTyVar, TcTyVarSet, TcType, TvSubst,
- substTy, substTyVar, tyVarsOfType, tcTyVarsOfTypes, mkTyConApp,
- getDFunTyKey, tcTyConAppTyCon, tcGetTyVar, mkTyVarTy,
- tidyOpenType, isRefineableTy
- )
-import qualified Type ( getTyVar_maybe )
-import Id ( idName, isLocalId, setIdType )
-import Var ( TyVar, Id, idType, tyVarName )
+import TcMType
+import TcType
+import TcGadt
+import qualified Type
+import Id
+import Var
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, nameModule )
-import PrelNames ( thFAKE )
+import RdrName
+import InstEnv
+import FamInstEnv
+import DataCon
+import TyCon
+import Class
+import Name
+import PrelNames
import NameEnv
-import OccName ( mkDFunOcc, occNameString )
-import HscTypes ( extendTypeEnvList, lookupType, TyThing(..), ExternalPackageState(..) )
-import SrcLoc ( SrcLoc, Located(..) )
+import OccName
+import HscTypes
+import SrcLoc
import Outputable
\end{code}
-- Try global envt
{ (eps,hpt) <- getEpsAndHpt
- ; case lookupType hpt (eps_PTE eps) name of {
+ ; dflags <- getDOpts
+ ; case lookupType dflags 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
+ { case nameModule_maybe name of
+ Nothing -> notFound name -- Internal names can happen in GHCi
+
+ Just mod | mod == tcg_mod env -- Names from this module
+ -> notFound name -- should be in tcg_type_env
+ | mod == thFAKE -- Names bound in TH declaration brackets
+ -> notFound name -- should be in tcg_env
+ | otherwise
+ -> tcImportDecl name -- Go find it in an interface
}}}}}
tcLookupField :: Name -> TcM Id -- Returns the selector Id
tcLookupLocatedTyCon :: Located Name -> TcM TyCon
tcLookupLocatedTyCon = addLocM tcLookupTyCon
+
+-- Look up the representation tycon of a family instance.
+-- Return the rep tycon and the corresponding rep args
+tcLookupFamInst :: TyCon -> [Type] -> TcM (TyCon, [Type])
+tcLookupFamInst tycon tys
+ | not (isOpenTyCon tycon)
+ = return (tycon, tys)
+ | otherwise
+ = do { env <- getGblEnv
+ ; eps <- getEps
+ ; let instEnv = (eps_fam_inst_env eps, tcg_fam_inst_env env)
+ ; case lookupFamInstEnv instEnv tycon tys of
+ [(subst,fam_inst)] -> return (rep_tc, substTyVars subst (tyConTyVars rep_tc))
+ where -- NB: assumption is that (tyConTyVars rep_tc) is in
+ -- the domain of the substitution
+ rep_tc = famInstTyCon fam_inst
+
+ other -> famInstNotFound tycon tys other
+ }
\end{code}
%************************************************************************
other -> pprPanic "tcLookupTyVar" (ppr name)
tcLookupId :: Name -> TcM Id
--- Used when we aren't interested in the binding level
--- Never a DataCon. (Why does that matter? see TcExpr.tcId)
+-- Used when we aren't interested in the binding level, nor refinement.
+-- The "no refinement" part means that we return the un-refined Id regardless
+--
+-- The Id is never a DataCon. (Why does that matter? see TcExpr.tcId)
tcLookupId name
= tcLookup name `thenM` \ thing ->
case thing of
- ATcId tc_id _ _ -> returnM tc_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
+ ATcId { tct_id = id} -> returnM id
+ AGlobal (AnId id) -> returnM id
+ other -> pprPanic "tcLookupId" (ppr name)
tcLookupLocalIds :: [Name] -> TcM [TcId]
-- We expect the variables to all be bound, and all at
where
lookup lenv lvl name
= case lookupNameEnv lenv name of
- Just (ATcId id lvl1 _) -> ASSERT( lvl == lvl1 ) id
- other -> pprPanic "tcLookupLocalIds" (ppr name)
+ Just (ATcId { tct_id = id, tct_level = lvl1 })
+ -> ASSERT( lvl == lvl1 ) id
+ other -> pprPanic "tcLookupLocalIds" (ppr name)
lclEnvElts :: TcLclEnv -> [TcTyThing]
lclEnvElts env = nameEnvElts (tcl_env env)
let
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]
+ extra_env = [ (name, ATcId { tct_id = id,
+ tct_level = th_lvl,
+ tct_type = id_ty,
+ tct_co = if isRefineableTy id_ty
+ then Just idHsWrapper
+ else Nothing })
+ | (name,id) <- names_w_ids, let id_ty = idType id]
le' = extendNameEnvList (tcl_env env) extra_env
rdr_env' = extendLocalRdrEnv (tcl_rdr env) [name | (name,_) <- names_w_ids]
in
Just d -> go tidy_env1 (d:acc) things
Nothing -> go tidy_env1 acc things
- ignore_it ty = not (tvs `intersectsVarSet` tyVarsOfType ty)
+ ignore_it ty = tvs `disjointVarSet` tyVarsOfType ty
-----------------------
-find_thing ignore_it tidy_env (ATcId id _ _)
+find_thing ignore_it tidy_env (ATcId { tct_id = id })
= zonkTcType (idType id) `thenM` \ id_ty ->
if ignore_it id_ty then
returnM (tidy_env, Nothing)
\end{code}
\begin{code}
-refineEnvironment :: TvSubst -> TcM a -> TcM a
+refineEnvironment :: Refinement -> TcM a -> TcM a
+-- I don't think I have to refine the set of global type variables in scope
+-- Reason: the refinement never increases that set
refineEnvironment reft thing_inside
+ | isEmptyRefinement reft -- Common case
+ = thing_inside
+ | otherwise
= 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 }
+ ; setLclEnv (env {tcl_env = le'}) 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
+ refine elt@(ATcId { tct_co = Just co, tct_type = ty })
+ | Just (co', ty') <- refineType reft ty
+ = elt { tct_co = Just (WpCo co' <.> co), tct_type = ty' }
+ refine (ATyVar tv ty)
+ | Just (_, ty') <- refineType reft ty
+ = ATyVar tv ty' -- Ignore the coercion that refineType returns
+
+ refine elt = elt -- Common case
\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.
[LSig Name] -- User pragmas recorded for generating
-- specialised instances
- | NewTypeDerived -- Used for deriving instances of newtypes, where the
- [Type] -- witness dictionary is identical to the argument
- -- dictionary. Hence no bindings, no pragmas
- -- The [Type] are the representation types
- -- See notes in TcDeriv
+ | NewTypeDerived -- Used for deriving instances of newtypes, where the
+ -- witness dictionary is identical to the argument
+ -- dictionary. Hence no bindings, no pragmas.
+ (Maybe [PredType])
+ -- Nothing => The newtype-derived instance involves type variables,
+ -- and the dfun has a type like df :: forall a. Eq a => Eq (T a)
+ -- Just (r:scs) => The newtype-defined instance has no type variables
+ -- so the dfun is just a constant, df :: Eq T
+ -- In this case we need to know waht the rep dict, r, and the
+ -- superclasses, scs, are. (In the Nothing case these are in the
+ -- dict fun's type.)
+ -- Invariant: these PredTypes have no free variables
+ -- NB: In both cases, the representation dict is the *first* dict.
pprInstInfo info = vcat [ptext SLIT("InstInfo:") <+> ppr (idType (iDFunId info))]
occNameString (getDFunTyKey ty)
dfun_occ = mkDFunOcc info_string is_boot index
- ; newGlobalBinder mod dfun_occ Nothing loc }
+ ; newGlobalBinder mod dfun_occ loc }
newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc)
\end{code}
+Make a name for the representation tycon of a data/newtype instance. It's an
+*external* name, like otber top-level names, and hence must be made with
+newGlobalBinder.
+
+\begin{code}
+newFamInstTyConName :: Name -> SrcLoc -> TcM Name
+newFamInstTyConName tc_name loc
+ = do { index <- nextDFunIndex
+ ; mod <- getModule
+ ; let occ = nameOccName tc_name
+ ; newGlobalBinder mod (mkInstTyTcOcc index occ) loc }
+\end{code}
+
%************************************************************************
%* *
wrongThingErr expected thing name
= failWithTc (pprTcTyThingCategory thing <+> quotes (ppr name) <+>
ptext SLIT("used as a") <+> text expected)
+
+famInstNotFound tycon tys what
+ = failWithTc (msg <+> quotes (ppr tycon <+> hsep (map pprParendType tys)))
+ where
+ msg = case what of
+ [] -> ptext SLIT("No instance for")
+ xs -> ptext SLIT("More than one instance for")
\end{code}
projects / ghc-hetmet.git / blobdiff