%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
-\section[DsMonad]{@DsMonad@: monadery used in desugaring}
+
+@DsMonad@: monadery used in desugaring
\begin{code}
module DsMonad (
- DsM, mappM, mapAndUnzipM,
- initDs, initDsTc, returnDs, thenDs, listDs, fixDs, mapAndUnzipDs,
- foldlDs, foldrDs,
-
- newTyVarsDs, newLocalName,
- duplicateLocalDs, newSysLocalDs, newSysLocalsDs, newUniqueId,
- newFailLocalDs,
- getSrcSpanDs, putSrcSpanDs,
- getModuleDs,
- newUnique,
- UniqSupply, newUniqueSupply,
- getDOptsDs,
- dsLookupGlobal, dsLookupGlobalId, dsLookupTyCon, dsLookupDataCon,
+ DsM, mapM, mapAndUnzipM,
+ initDs, initDsTc, fixDs,
+ foldlM, foldrM, ifDOptM, unsetOptM,
+ Applicative(..),(<$>),
+
+ newLocalName,
+ duplicateLocalDs, newSysLocalDs, newSysLocalsDs, newUniqueId,
+ newFailLocalDs, newPredVarDs,
+ getSrcSpanDs, putSrcSpanDs,
+ getModuleDs,
+ mkPrintUnqualifiedDs,
+ newUnique,
+ UniqSupply, newUniqueSupply,
+ getDOptsDs, getGhcModeDs, doptDs,
+ dsLookupGlobal, dsLookupGlobalId, dsLookupDPHId, dsLookupTyCon, dsLookupDataCon,
+ dsLookupClass,
DsMetaEnv, DsMetaVal(..), dsLookupMetaEnv, dsExtendMetaEnv,
+ dsLoadModule,
+
-- Warnings
DsWarning, warnDs, failWithDs,
-- Data types
DsMatchContext(..),
- EquationInfo(..), MatchResult(..), DsWrapper, idWrapper,
+ EquationInfo(..), MatchResult(..), DsWrapper, idDsWrapper,
CanItFail(..), orFail
) where
-#include "HsVersions.h"
-
import TcRnMonad
-import CoreSyn ( CoreExpr )
-import HsSyn ( HsExpr, HsMatchContext, Pat )
-import TcIface ( tcIfaceGlobal )
-import RdrName ( GlobalRdrEnv )
-import HscTypes ( TyThing(..), TypeEnv, HscEnv(..),
- tyThingId, tyThingTyCon, tyThingDataCon, mkPrintUnqualified )
-import Bag ( emptyBag, snocBag )
-import DataCon ( DataCon )
-import TyCon ( TyCon )
-import Id ( mkSysLocal, setIdUnique, Id )
-import Module ( Module )
-import Var ( TyVar, setTyVarUnique )
+import CoreSyn
+import HsSyn
+import TcIface
+import LoadIface
+import RdrName
+import HscTypes
+import Bag
+import DataCon
+import TyCon
+import Class
+import Id
+import Module
+import Var
import Outputable
-import SrcLoc ( noSrcSpan, SrcSpan )
-import Type ( Type )
-import UniqSupply ( UniqSupply, uniqsFromSupply )
-import Name ( Name, nameOccName )
+import SrcLoc
+import Type
+import UniqSupply
+import Name
import NameEnv
-import OccName ( occNameFS )
-import DynFlags ( DynFlags )
-import ErrUtils ( Messages, mkWarnMsg, mkErrMsg,
- printErrorsAndWarnings, errorsFound )
-import DATA_IOREF ( newIORef, readIORef )
+import DynFlags
+import ErrUtils
+import FastString
-infixr 9 `thenDs`
+import Data.IORef
\end{code}
%************************************************************************
\begin{code}
data DsMatchContext
= DsMatchContext (HsMatchContext Name) SrcSpan
- | NoMatchContext
deriving ()
data EquationInfo
- = EqnInfo { eqn_wrap :: DsWrapper, -- Bindings
- eqn_pats :: [Pat Id], -- The patterns for an eqn
+ = EqnInfo { eqn_pats :: [Pat Id], -- The patterns for an eqn
eqn_rhs :: MatchResult } -- What to do after match
+instance Outputable EquationInfo where
+ ppr (EqnInfo pats _) = ppr pats
+
type DsWrapper = CoreExpr -> CoreExpr
-idWrapper e = e
+idDsWrapper :: DsWrapper
+idDsWrapper e = e
-- The semantics of (match vs (EqnInfo wrap pats rhs)) is the MatchResult
-- \fail. wrap (case vs of { pats -> rhs fail })
data CanItFail = CanFail | CantFail
+orFail :: CanItFail -> CanItFail -> CanItFail
orFail CantFail CantFail = CantFail
-orFail _ _ = CanFail
+orFail _ _ = CanFail
\end{code}
type DsM result = TcRnIf DsGblEnv DsLclEnv result
-- Compatibility functions
+fixDs :: (a -> DsM a) -> DsM a
fixDs = fixM
-thenDs = thenM
-returnDs = returnM
-listDs = sequenceM
-foldlDs = foldlM
-foldrDs = foldrM
-mapAndUnzipDs = mapAndUnzipM
-
type DsWarning = (SrcSpan, SDoc)
-- Not quite the same as a WarnMsg, we have an SDoc here
initDs :: HscEnv
-> Module -> GlobalRdrEnv -> TypeEnv
-> DsM a
- -> IO (Maybe a)
+ -> IO (Messages, Maybe a)
-- Print errors and warnings, if any arise
initDs hsc_env mod rdr_env type_env thing_inside
= do { msg_var <- newIORef (emptyBag, emptyBag)
- ; let (ds_gbl_env, ds_lcl_env) = mkDsEnvs mod rdr_env type_env msg_var
+ ; let dflags = hsc_dflags hsc_env
+ ; (ds_gbl_env, ds_lcl_env) <- mkDsEnvs dflags mod rdr_env type_env msg_var
; either_res <- initTcRnIf 'd' hsc_env ds_gbl_env ds_lcl_env $
tryM thing_inside -- Catch exceptions (= errors during desugaring)
-- Display any errors and warnings
-- Note: if -Werror is used, we don't signal an error here.
- ; let dflags = hsc_dflags hsc_env
; msgs <- readIORef msg_var
- ; printErrorsAndWarnings dflags msgs
; let final_res | errorsFound dflags msgs = Nothing
| otherwise = case either_res of
-- a UserError exception. Then it should have put an error
-- message in msg_var, so we just discard the exception
- ; return final_res }
+ ; return (msgs, final_res) }
initDsTc :: DsM a -> TcM a
initDsTc thing_inside
= do { this_mod <- getModule
; tcg_env <- getGblEnv
; msg_var <- getErrsVar
+ ; dflags <- getDOpts
; let type_env = tcg_type_env tcg_env
rdr_env = tcg_rdr_env tcg_env
- ; setEnvs (mkDsEnvs this_mod rdr_env type_env msg_var) thing_inside }
-
-mkDsEnvs :: Module -> GlobalRdrEnv -> TypeEnv
- -> IORef Messages -> (DsGblEnv, DsLclEnv)
-mkDsEnvs mod rdr_env type_env msg_var
- = (gbl_env, lcl_env)
- where
- if_genv = IfGblEnv { if_rec_types = Just (mod, return type_env) }
- if_lenv = mkIfLclEnv mod (ptext SLIT("GHC error in desugarer lookup in") <+> ppr mod)
- gbl_env = DsGblEnv { ds_mod = mod,
- ds_if_env = (if_genv, if_lenv),
- ds_unqual = mkPrintUnqualified rdr_env,
- ds_msgs = msg_var }
- lcl_env = DsLclEnv { ds_meta = emptyNameEnv,
- ds_loc = noSrcSpan }
+ ; ds_envs <- liftIO $ mkDsEnvs dflags this_mod rdr_env type_env msg_var
+ ; setEnvs ds_envs thing_inside }
+
+mkDsEnvs :: DynFlags -> Module -> GlobalRdrEnv -> TypeEnv -> IORef Messages -> IO (DsGblEnv, DsLclEnv)
+mkDsEnvs dflags mod rdr_env type_env msg_var
+ = do -- TODO: unnecessarily monadic
+ let if_genv = IfGblEnv { if_rec_types = Just (mod, return type_env) }
+ if_lenv = mkIfLclEnv mod (ptext (sLit "GHC error in desugarer lookup in") <+> ppr mod)
+ gbl_env = DsGblEnv { ds_mod = mod,
+ ds_if_env = (if_genv, if_lenv),
+ ds_unqual = mkPrintUnqualified dflags rdr_env,
+ ds_msgs = msg_var}
+ lcl_env = DsLclEnv { ds_meta = emptyNameEnv,
+ ds_loc = noSrcSpan }
+
+ return (gbl_env, lcl_env)
\end{code}
%************************************************************************
\begin{code}
-- Make a new Id with the same print name, but different type, and new unique
-newUniqueId :: Name -> Type -> DsM Id
-newUniqueId id ty
- = newUnique `thenDs` \ uniq ->
- returnDs (mkSysLocal (occNameFS (nameOccName id)) uniq ty)
+newUniqueId :: Id -> Type -> DsM Id
+newUniqueId id = mkSysLocalM (occNameFS (nameOccName (idName id)))
duplicateLocalDs :: Id -> DsM Id
duplicateLocalDs old_local
- = newUnique `thenDs` \ uniq ->
- returnDs (setIdUnique old_local uniq)
-
+ = do { uniq <- newUnique
+ ; return (setIdUnique old_local uniq) }
+
+newPredVarDs :: PredType -> DsM Var
+newPredVarDs pred
+ | isEqPred pred
+ = do { uniq <- newUnique;
+ ; let name = mkSystemName uniq (mkOccNameFS tcName (fsLit "co_pv"))
+ kind = mkPredTy pred
+ ; return (mkCoVar name kind) }
+ | otherwise
+ = newSysLocalDs (mkPredTy pred)
+
newSysLocalDs, newFailLocalDs :: Type -> DsM Id
-newSysLocalDs ty
- = newUnique `thenDs` \ uniq ->
- returnDs (mkSysLocal FSLIT("ds") uniq ty)
-
-newSysLocalsDs tys = mappM newSysLocalDs tys
+newSysLocalDs = mkSysLocalM (fsLit "ds")
+newFailLocalDs = mkSysLocalM (fsLit "fail")
-newFailLocalDs ty
- = newUnique `thenDs` \ uniq ->
- returnDs (mkSysLocal FSLIT("fail") uniq ty)
- -- The UserLocal bit just helps make the code a little clearer
-\end{code}
-
-\begin{code}
-newTyVarsDs :: [TyVar] -> DsM [TyVar]
-newTyVarsDs tyvar_tmpls
- = newUniqueSupply `thenDs` \ uniqs ->
- returnDs (zipWith setTyVarUnique tyvar_tmpls (uniqsFromSupply uniqs))
+newSysLocalsDs :: [Type] -> DsM [Id]
+newSysLocalsDs tys = mapM newSysLocalDs tys
\end{code}
We can also reach out and either set/grab location information from
getDOptsDs :: DsM DynFlags
getDOptsDs = getDOpts
+doptDs :: DynFlag -> TcRnIf gbl lcl Bool
+doptDs = doptM
+
+getGhcModeDs :: DsM GhcMode
+getGhcModeDs = getDOptsDs >>= return . ghcMode
+
getModuleDs :: DsM Module
getModuleDs = do { env <- getGblEnv; return (ds_mod env) }
warnDs warn = do { env <- getGblEnv
; loc <- getSrcSpanDs
; let msg = mkWarnMsg loc (ds_unqual env)
- (ptext SLIT("Warning:") <+> warn)
+ (ptext (sLit "Warning:") <+> warn)
; updMutVar (ds_msgs env) (\ (w,e) -> (w `snocBag` msg, e)) }
- where
failWithDs :: SDoc -> DsM a
failWithDs err
; let msg = mkErrMsg loc (ds_unqual env) err
; updMutVar (ds_msgs env) (\ (w,e) -> (w, e `snocBag` msg))
; failM }
- where
+
+mkPrintUnqualifiedDs :: DsM PrintUnqualified
+mkPrintUnqualifiedDs = ds_unqual <$> getGblEnv
\end{code}
\begin{code}
+instance MonadThings (IOEnv (Env DsGblEnv DsLclEnv)) where
+ lookupThing = dsLookupGlobal
+
dsLookupGlobal :: Name -> DsM TyThing
-- Very like TcEnv.tcLookupGlobal
dsLookupGlobal name
dsLookupGlobalId :: Name -> DsM Id
dsLookupGlobalId name
- = dsLookupGlobal name `thenDs` \ thing ->
- returnDs (tyThingId thing)
+ = tyThingId <$> dsLookupGlobal name
+
+-- Looking up a global DPH 'Id' is like 'dsLookupGlobalId', but the package, in which the looked
+-- up name is located, varies with the active DPH backend.
+--
+dsLookupDPHId :: (PackageId -> Name) -> DsM Id
+dsLookupDPHId nameInPkg
+ = do { dflags <- getDOpts
+ ; case dphPackageMaybe dflags of
+ Just pkg -> tyThingId <$> dsLookupGlobal (nameInPkg pkg)
+ Nothing -> failWithDs $ ptext err
+ }
+ where
+ err = sLit "To use -XParallelArrays select a DPH backend with -fdph-par or -fdph-seq"
dsLookupTyCon :: Name -> DsM TyCon
dsLookupTyCon name
- = dsLookupGlobal name `thenDs` \ thing ->
- returnDs (tyThingTyCon thing)
+ = tyThingTyCon <$> dsLookupGlobal name
dsLookupDataCon :: Name -> DsM DataCon
dsLookupDataCon name
- = dsLookupGlobal name `thenDs` \ thing ->
- returnDs (tyThingDataCon thing)
+ = tyThingDataCon <$> dsLookupGlobal name
+
+dsLookupClass :: Name -> DsM Class
+dsLookupClass name
+ = tyThingClass <$> dsLookupGlobal name
\end{code}
\begin{code}
= updLclEnv (\env -> env { ds_meta = ds_meta env `plusNameEnv` menv }) thing_inside
\end{code}
+\begin{code}
+dsLoadModule :: SDoc -> Module -> DsM ()
+dsLoadModule doc mod
+ = do { env <- getGblEnv
+ ; setEnvs (ds_if_env env)
+ (loadSysInterface doc mod >> return ())
+ }
+\end{code}