@DsMonad@: monadery used in desugaring
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module DsMonad (
- DsM, mappM, mapAndUnzipM,
- initDs, initDsTc, returnDs, thenDs, listDs, fixDs, mapAndUnzipDs,
- foldlDs, foldrDs,
+ DsM, mapM, mapAndUnzipM,
+ initDs, initDsTc, fixDs,
+ foldlM, foldrM, ifOptM,
+ Applicative(..),(<$>),
newTyVarsDs, newLocalName,
duplicateLocalDs, newSysLocalDs, newSysLocalsDs, newUniqueId,
import OccName
import DynFlags
import ErrUtils
+import MonadUtils
+import FastString
import Data.IORef
-
-infixr 9 `thenDs`
\end{code}
%************************************************************************
eqn_rhs :: MatchResult } -- What to do after match
type DsWrapper = CoreExpr -> CoreExpr
+idDsWrapper :: DsWrapper
idDsWrapper e = e
-- The semantics of (match vs (EqnInfo wrap pats rhs)) is the MatchResult
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 hsc_env mod rdr_env type_env thing_inside
= do { msg_var <- newIORef (emptyBag, emptyBag)
- ; (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
= 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
- ; ds_envs <- ioToIOEnv$ mkDsEnvs this_mod rdr_env type_env msg_var
+ ; ds_envs <- liftIO $ mkDsEnvs dflags this_mod rdr_env type_env msg_var
; setEnvs ds_envs thing_inside }
-mkDsEnvs :: Module -> GlobalRdrEnv -> TypeEnv -> IORef Messages -> IO (DsGblEnv, DsLclEnv)
-mkDsEnvs mod rdr_env type_env msg_var
- = do
- sites_var <- newIORef []
+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 rdr_env,
+ ds_unqual = mkPrintUnqualified dflags rdr_env,
ds_msgs = msg_var}
lcl_env = DsLclEnv { ds_meta = emptyNameEnv,
ds_loc = noSrcSpan }
\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 ty = do
+ uniq <- newUnique
+ return (mkSysLocal (occNameFS (nameOccName id)) uniq ty)
duplicateLocalDs :: Id -> DsM Id
-duplicateLocalDs old_local
- = newUnique `thenDs` \ uniq ->
- returnDs (setIdUnique old_local uniq)
+duplicateLocalDs old_local = do
+ uniq <- newUnique
+ return (setIdUnique old_local uniq)
newSysLocalDs, newFailLocalDs :: Type -> DsM Id
-newSysLocalDs ty
- = newUnique `thenDs` \ uniq ->
- returnDs (mkSysLocal FSLIT("ds") uniq ty)
+newSysLocalDs ty = do
+ uniq <- newUnique
+ return (mkSysLocal FSLIT("ds") uniq ty)
-newSysLocalsDs tys = mappM newSysLocalDs tys
+newSysLocalsDs :: [Type] -> DsM [Id]
+newSysLocalsDs tys = mapM newSysLocalDs tys
-newFailLocalDs ty
- = newUnique `thenDs` \ uniq ->
- returnDs (mkSysLocal FSLIT("fail") uniq ty)
+newFailLocalDs ty = do
+ uniq <- newUnique
+ return (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))
+newTyVarsDs tyvar_tmpls = do
+ uniqs <- newUniqueSupply
+ return (zipWith setTyVarUnique tyvar_tmpls (uniqsFromSupply uniqs))
\end{code}
We can also reach out and either set/grab location information from
dsLookupGlobalId :: Name -> DsM Id
dsLookupGlobalId name
- = dsLookupGlobal name `thenDs` \ thing ->
- returnDs (tyThingId thing)
+ = tyThingId <$> dsLookupGlobal name
dsLookupTyCon :: Name -> DsM TyCon
dsLookupTyCon name
- = dsLookupGlobal name `thenDs` \ thing ->
- returnDs (tyThingTyCon thing)
+ = tyThingTyCon <$> dsLookupGlobal name
dsLookupDataCon :: Name -> DsM DataCon
dsLookupDataCon name
- = dsLookupGlobal name `thenDs` \ thing ->
- returnDs (tyThingDataCon thing)
+ = tyThingDataCon <$> dsLookupGlobal name
dsLookupClass :: Name -> DsM Class
dsLookupClass name
- = dsLookupGlobal name `thenDs` \ thing ->
- returnDs (tyThingClass thing)
+ = tyThingClass <$> dsLookupGlobal name
\end{code}
\begin{code}
projects / ghc-hetmet.git / blobdiff