free variables.
\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 RnExpr (
rnLExpr, rnExpr, rnStmts
) where
import HsSyn
import TcRnMonad
import RnEnv
-import HscTypes ( availNames )
-import RnNames ( getLocalDeclBinders, extendRdrEnvRn )
import RnTypes ( rnHsTypeFVs,
mkOpFormRn, mkOpAppRn, mkNegAppRn, checkSectionPrec)
-import RnPat (rnQuasiQuote, rnOverLit, rnPatsAndThen_LocalRightwards, rnBindPat,
- localRecNameMaker, rnLit,
- rnHsRecFields_Con, rnHsRecFields_Update, checkTupSize)
-import RdrName ( mkRdrUnqual )
+import RnPat
import DynFlags ( DynFlag(..) )
import BasicTypes ( FixityDirection(..) )
-import SrcLoc ( SrcSpan )
import PrelNames ( thFAKE, hasKey, assertIdKey, assertErrorName,
loopAName, choiceAName, appAName, arrAName, composeAName, firstAName,
negateName, thenMName, bindMName, failMName, groupWithName )
-import Name ( Name, nameOccName, nameModule, nameIsLocalOrFrom )
+import Name
import NameSet
-import LazyUniqFM
-import RdrName ( RdrName, extendLocalRdrEnv, lookupLocalRdrEnv, hideSomeUnquals )
+import RdrName
import LoadIface ( loadInterfaceForName )
-import UniqSet ( isEmptyUniqSet, emptyUniqSet )
+import UniqSet
import List ( nub )
import Util ( isSingleton )
import ListSetOps ( removeDups )
import Maybes ( expectJust )
import Outputable
-import SrcLoc ( Located(..), unLoc, getLoc, noLoc )
+import SrcLoc
import FastString
import List ( unzip4 )
mappM :: (Monad m) => (a -> m b) -> [a] -> m [b]
mappM = mapM
-mappM_ :: (Monad m) => (a -> m b) -> [a] -> m ()
-mappM_ = mapM_
-
checkM :: Monad m => Bool -> m () -> m ()
checkM = unless
\end{code}
let
acc' = acc `plusFV` fvExpr
in
- (grubby_seqNameSet acc' rnExprs') exprs acc' `thenM` \ (exprs', fvExprs) ->
+ acc' `seq` rnExprs' exprs acc' `thenM` \ (exprs', fvExprs) ->
returnM (expr':exprs', fvExprs)
-
--- Grubby little function to do "seq" on namesets; replace by proper seq when GHC can do seq
-grubby_seqNameSet ns result | isEmptyUniqSet ns = result
- | otherwise = result
\end{code}
Variables. We look up the variable and return the resulting name.
rnBracket br_body `thenM` \ (body', fvs_e) ->
returnM (HsBracket body', fvs_e)
-rnExpr e@(HsSpliceE splice)
+rnExpr (HsSpliceE splice)
= rnSplice splice `thenM` \ (splice', fvs) ->
returnM (HsSpliceE splice', fvs)
#ifndef GHCI
rnExpr e@(HsQuasiQuoteE _) = pprPanic "Cant do quasiquotation without GHCi" (ppr e)
#else
-rnExpr e@(HsQuasiQuoteE qq)
+rnExpr (HsQuasiQuoteE qq)
= rnQuasiQuote qq `thenM` \ (qq', fvs_qq) ->
runQuasiQuoteExpr qq' `thenM` \ (L _ expr') ->
rnExpr expr' `thenM` \ (expr'', fvs_expr) ->
rnLExpr expr `thenM` \ (expr',fvExpr) ->
returnM (HsLet binds' expr', fvExpr)
-rnExpr e@(HsDo do_or_lc stmts body _)
+rnExpr (HsDo do_or_lc stmts body _)
= do { ((stmts', body'), fvs) <- rnStmts do_or_lc stmts $
rnLExpr body
; return (HsDo do_or_lc stmts' body' placeHolderType, fvs) }
= rnExprs exps `thenM` \ (exps', fvs) ->
returnM (ExplicitPArr placeHolderType exps', fvs)
-rnExpr e@(ExplicitTuple exps boxity)
+rnExpr (ExplicitTuple exps boxity)
= checkTupSize (length exps) `thenM_`
rnExprs exps `thenM` \ (exps', fvs) ->
returnM (ExplicitTuple exps' boxity, fvs)
%************************************************************************
\begin{code}
+rnCmdArgs :: [LHsCmdTop RdrName] -> RnM ([LHsCmdTop Name], FreeVars)
rnCmdArgs [] = returnM ([], emptyFVs)
rnCmdArgs (arg:args)
= rnCmdTop arg `thenM` \ (arg',fvArg) ->
rnCmdArgs args `thenM` \ (args',fvArgs) ->
returnM (arg':args', fvArg `plusFV` fvArgs)
-
+rnCmdTop :: LHsCmdTop RdrName -> RnM (LHsCmdTop Name, FreeVars)
rnCmdTop = wrapLocFstM rnCmdTop'
where
rnCmdTop' (HsCmdTop cmd _ _ _)
convertOpFormsCmd (HsPar c) = HsPar (convertOpFormsLCmd c)
--- gaw 2004
convertOpFormsCmd (HsCase exp matches)
= HsCase exp (convertOpFormsMatch matches)
-- caught by the type checker)
convertOpFormsCmd c = c
+convertOpFormsStmt :: StmtLR id id -> StmtLR id id
convertOpFormsStmt (BindStmt pat cmd _ _)
= BindStmt pat (convertOpFormsLCmd cmd) noSyntaxExpr noSyntaxExpr
convertOpFormsStmt (ExprStmt cmd _ _)
= RecStmt (map (fmap convertOpFormsStmt) stmts) lvs rvs es binds
convertOpFormsStmt stmt = stmt
+convertOpFormsMatch :: MatchGroup id -> MatchGroup id
convertOpFormsMatch (MatchGroup ms ty)
= MatchGroup (map (fmap convert) ms) ty
where convert (Match pat mty grhss)
= Match pat mty (convertOpFormsGRHSs grhss)
+convertOpFormsGRHSs :: GRHSs id -> GRHSs id
convertOpFormsGRHSs (GRHSs grhss binds)
= GRHSs (map convertOpFormsGRHS grhss) binds
+convertOpFormsGRHS :: Located (GRHS id) -> Located (GRHS id)
convertOpFormsGRHS = fmap convert
where
convert (GRHS stmts cmd) = GRHS stmts (convertOpFormsLCmd cmd)
methodNamesCmd :: HsCmd Name -> CmdNeeds
-methodNamesCmd cmd@(HsArrApp _arrow _arg _ HsFirstOrderApp _rtl)
+methodNamesCmd (HsArrApp _arrow _arg _ HsFirstOrderApp _rtl)
= emptyFVs
-methodNamesCmd cmd@(HsArrApp _arrow _arg _ HsHigherOrderApp _rtl)
+methodNamesCmd (HsArrApp _arrow _arg _ HsHigherOrderApp _rtl)
= unitFV appAName
-methodNamesCmd cmd@(HsArrForm {}) = emptyFVs
+methodNamesCmd (HsArrForm {}) = emptyFVs
methodNamesCmd (HsPar c) = methodNamesLCmd c
-methodNamesCmd (HsIf p c1 c2)
+methodNamesCmd (HsIf _ c1 c2)
= methodNamesLCmd c1 `plusFV` methodNamesLCmd c2 `addOneFV` choiceAName
-methodNamesCmd (HsLet b c) = methodNamesLCmd c
+methodNamesCmd (HsLet _ c) = methodNamesLCmd c
-methodNamesCmd (HsDo sc stmts body ty)
+methodNamesCmd (HsDo _ stmts body _)
= methodNamesStmts stmts `plusFV` methodNamesLCmd body
-methodNamesCmd (HsApp c e) = methodNamesLCmd c
+methodNamesCmd (HsApp c _) = methodNamesLCmd c
methodNamesCmd (HsLam match) = methodNamesMatch match
-methodNamesCmd (HsCase scrut matches)
+methodNamesCmd (HsCase _ matches)
= methodNamesMatch matches `addOneFV` choiceAName
-methodNamesCmd other = emptyFVs
+methodNamesCmd _ = emptyFVs
-- Other forms can't occur in commands, but it's not convenient
-- to error here so we just do what's convenient.
-- The type checker will complain later
---------------------------------------------------
+methodNamesMatch :: MatchGroup Name -> FreeVars
methodNamesMatch (MatchGroup ms _)
= plusFVs (map do_one ms)
where
- do_one (L _ (Match pats sig_ty grhss)) = methodNamesGRHSs grhss
+ do_one (L _ (Match _ _ grhss)) = methodNamesGRHSs grhss
-------------------------------------------------
-- gaw 2004
-methodNamesGRHSs (GRHSs grhss binds) = plusFVs (map methodNamesGRHS grhss)
+methodNamesGRHSs :: GRHSs Name -> FreeVars
+methodNamesGRHSs (GRHSs grhss _) = plusFVs (map methodNamesGRHS grhss)
-------------------------------------------------
-methodNamesGRHS (L _ (GRHS stmts rhs)) = methodNamesLCmd rhs
+
+methodNamesGRHS :: Located (GRHS Name) -> CmdNeeds
+methodNamesGRHS (L _ (GRHS _ rhs)) = methodNamesLCmd rhs
---------------------------------------------------
+methodNamesStmts :: [Located (StmtLR Name Name)] -> FreeVars
methodNamesStmts stmts = plusFVs (map methodNamesLStmt stmts)
---------------------------------------------------
+methodNamesLStmt :: Located (StmtLR Name Name) -> FreeVars
methodNamesLStmt = methodNamesStmt . unLoc
+methodNamesStmt :: StmtLR Name Name -> FreeVars
methodNamesStmt (ExprStmt cmd _ _) = methodNamesLCmd cmd
-methodNamesStmt (BindStmt pat cmd _ _) = methodNamesLCmd cmd
+methodNamesStmt (BindStmt _ cmd _ _) = methodNamesLCmd cmd
methodNamesStmt (RecStmt stmts _ _ _ _)
= methodNamesStmts stmts `addOneFV` loopAName
-methodNamesStmt (LetStmt b) = emptyFVs
-methodNamesStmt (ParStmt ss) = emptyFVs
+methodNamesStmt (LetStmt _) = emptyFVs
+methodNamesStmt (ParStmt _) = emptyFVs
methodNamesStmt (TransformStmt _ _ _) = emptyFVs
methodNamesStmt (GroupStmt _ _) = emptyFVs
-- ParStmt, TransformStmt and GroupStmt can't occur in commands, but it's not convenient to error
%************************************************************************
\begin{code}
+rnArithSeq :: ArithSeqInfo RdrName -> RnM (ArithSeqInfo Name, FreeVars)
rnArithSeq (From expr)
= rnLExpr expr `thenM` \ (expr', fvExpr) ->
returnM (From expr', fvExpr)
%************************************************************************
\begin{code}
+rnBracket :: HsBracket RdrName -> RnM (HsBracket Name, FreeVars)
rnBracket (VarBr n) = do { name <- lookupOccRn n
; this_mod <- getModule
; checkM (nameIsLocalOrFrom this_mod name) $ -- Reason: deprecation checking asumes the
; return () } -- only way that is going to happen
; returnM (VarBr name, unitFV name) }
where
- msg = ptext SLIT("Need interface for Template Haskell quoted Name")
+ msg = ptext (sLit "Need interface for Template Haskell quoted Name")
rnBracket (ExpBr e) = do { (e', fvs) <- rnLExpr e
; return (ExpBr e', fvs) }
-rnBracket (PatBr p) = do { addErr (ptext SLIT("Tempate Haskell pattern brackets are not supported yet"));
+rnBracket (PatBr _) = do { addErr (ptext (sLit "Tempate Haskell pattern brackets are not supported yet"));
failM }
rnBracket (TypBr t) = do { (t', fvs) <- rnHsTypeFVs doc t
; return (TypBr t', fvs) }
where
- doc = ptext SLIT("In a Template-Haskell quoted type")
+ doc = ptext (sLit "In a Template-Haskell quoted type")
rnBracket (DecBr group)
= do { gbl_env <- getGblEnv
-- Used for cases *other* than recursive mdo
-- Implements nested scopes
-rnNormalStmts ctxt [] thing_inside
+rnNormalStmts _ [] thing_inside
= do { (thing, fvs) <- thing_inside
; return (([],thing), fvs) }
-> RnM (thing, FreeVars)
-> RnM ((Stmt Name, thing), FreeVars)
-rnStmt ctxt (ExprStmt expr _ _) thing_inside
+rnStmt _ (ExprStmt expr _ _) thing_inside
= do { (expr', fv_expr) <- rnLExpr expr
; (then_op, fvs1) <- lookupSyntaxName thenMName
; (thing, fvs2) <- thing_inside
-- fv_expr shouldn't really be filtered by the rnPatsAndThen
-- but it does not matter because the names are unique
-rnStmt ctxt (LetStmt binds) thing_inside = do
- checkErr (ok ctxt binds) (badIpBinds (ptext SLIT("a parallel list comprehension:")) binds)
- rnLocalBindsAndThen binds $ \binds' -> do
- (thing, fvs) <- thing_inside
- return ((LetStmt binds', thing), fvs)
- where
- -- We do not allow implicit-parameter bindings in a parallel
- -- list comprehension. I'm not sure what it might mean.
- ok (ParStmtCtxt _) (HsIPBinds _) = False
- ok _ _ = True
+rnStmt ctxt (LetStmt binds) thing_inside
+ = do { checkLetStmt ctxt binds
+ ; rnLocalBindsAndThen binds $ \binds' -> do
+ { (thing, fvs) <- thing_inside
+ ; return ((LetStmt binds', thing), fvs) } }
rnStmt ctxt (RecStmt rec_stmts _ _ _ _) thing_inside
- =
- rn_rec_stmts_and_then rec_stmts $ \ segs ->
- thing_inside `thenM` \ (thing, fvs) ->
- let
- segs_w_fwd_refs = addFwdRefs segs
- (ds, us, fs, rec_stmts') = unzip4 segs_w_fwd_refs
- later_vars = nameSetToList (plusFVs ds `intersectNameSet` fvs)
- fwd_vars = nameSetToList (plusFVs fs)
- uses = plusFVs us
- rec_stmt = RecStmt rec_stmts' later_vars fwd_vars [] emptyLHsBinds
- in
- returnM ((rec_stmt, thing), uses `plusFV` fvs)
- where
- doc = text "In a recursive do statement"
+ = do { checkRecStmt ctxt
+ ; rn_rec_stmts_and_then rec_stmts $ \ segs -> do
+ { (thing, fvs) <- thing_inside
+ ; let
+ segs_w_fwd_refs = addFwdRefs segs
+ (ds, us, fs, rec_stmts') = unzip4 segs_w_fwd_refs
+ later_vars = nameSetToList (plusFVs ds `intersectNameSet` fvs)
+ fwd_vars = nameSetToList (plusFVs fs)
+ uses = plusFVs us
+ rec_stmt = RecStmt rec_stmts' later_vars fwd_vars [] emptyLHsBinds
+ ; return ((rec_stmt, thing), uses `plusFV` fvs) } }
+
+rnStmt ctxt (ParStmt segs) thing_inside
+ = do { checkParStmt ctxt
+ ; ((segs', thing), fvs) <- rnParallelStmts (ParStmtCtxt ctxt) segs thing_inside
+ ; return ((ParStmt segs', thing), fvs) }
rnStmt ctxt (TransformStmt (stmts, _) usingExpr maybeByExpr) thing_inside = do
- checkIsTransformableListComp ctxt
+ checkTransformStmt ctxt
(usingExpr', fv_usingExpr) <- rnLExpr usingExpr
((stmts', binders, (maybeByExpr', thing)), fvs) <-
- rnNormalStmtsAndFindUsedBinders (TransformStmtCtxt ctxt) stmts $ \unshadowed_bndrs -> do
+ rnNormalStmtsAndFindUsedBinders (TransformStmtCtxt ctxt) stmts $ \_unshadowed_bndrs -> do
(maybeByExpr', fv_maybeByExpr) <- rnMaybeLExpr maybeByExpr
(thing, fv_thing) <- thing_inside
return (Just expr', fv_expr)
rnStmt ctxt (GroupStmt (stmts, _) groupByClause) thing_inside = do
- checkIsTransformableListComp ctxt
+ checkTransformStmt ctxt
-- We must rename the using expression in the context before the transform is begun
groupByClauseAction <-
traceRn (text "rnStmt: implicitly rebound these used binders:" <+> ppr usedBinderMap)
return ((GroupStmt (stmts', usedBinderMap) groupByClause', thing), fvs)
-rnStmt ctxt (ParStmt segs) thing_inside
- = do { parallel_list_comp <- doptM Opt_ParallelListComp
- ; checkM parallel_list_comp parStmtErr
- ; ((segs', thing), fvs) <- rnParallelStmts (ParStmtCtxt ctxt) segs thing_inside
- ; return ((ParStmt segs', thing), fvs) }
-
-
rnNormalStmtsAndFindUsedBinders :: HsStmtContext Name
-> [LStmt RdrName]
-> ([Name] -> RnM (thing, FreeVars))
-- Flatten the tuple returned by the above call a bit!
return ((stmts', used_bndrs, inner_thing), fvs)
-
+rnParallelStmts :: HsStmtContext Name -> [([LStmt RdrName], [RdrName])]
+ -> RnM (thing, FreeVars)
+ -> RnM (([([LStmt Name], [Name])], thing), FreeVars)
rnParallelStmts ctxt segs thing_inside = do
orig_lcl_env <- getLocalRdrEnv
go orig_lcl_env [] segs
return (((seg':segs'), thing), delListFromNameSet fvs bndrs)
cmpByOcc n1 n2 = nameOccName n1 `compare` nameOccName n2
- dupErr vs = addErr (ptext SLIT("Duplicate binding in parallel list comprehension for:")
+ dupErr vs = addErr (ptext (sLit "Duplicate binding in parallel list comprehension for:")
<+> quotes (ppr (head vs)))
-
-
-checkIsTransformableListComp :: HsStmtContext Name -> RnM ()
-checkIsTransformableListComp ctxt = do
- -- Ensure we are really within a list comprehension because otherwise the
- -- desugarer will break when we come to operate on a parallel array
- checkM (notParallelArray ctxt) transformStmtOutsideListCompErr
-
- -- Ensure the user has turned the correct flag on
- transform_list_comp <- doptM Opt_TransformListComp
- checkM transform_list_comp transformStmtErr
- where
- notParallelArray PArrComp = False
- notParallelArray _ = True
-
\end{code}
(stmts', fvs) = segsToStmts grouped_segs fvs_later
; return ((stmts', thing), fvs) }
- where
- doc = text "In a recursive mdo-expression"
---------------------------------------------
-- the FreeVars of the Segments
-> ([Segment (LStmt Name)] -> RnM (a, FreeVars))
-> RnM (a, FreeVars)
-rn_rec_stmts_and_then s cont = do
- -- (A) make the mini fixity env for all of the stmts
- fix_env <- makeMiniFixityEnv (collectRecStmtsFixities s)
-
- -- (B) do the LHSes
- new_lhs_and_fv <- rn_rec_stmts_lhs fix_env s
+rn_rec_stmts_and_then s cont
+ = do { -- (A) Make the mini fixity env for all of the stmts
+ fix_env <- makeMiniFixityEnv (collectRecStmtsFixities s)
- -- bring them and their fixities into scope
- let bound_names = map unLoc $ collectLStmtsBinders (map fst new_lhs_and_fv)
- bindLocalNamesFV_WithFixities bound_names fix_env $
- warnUnusedLocalBinds bound_names $ do
+ -- (B) Do the LHSes
+ ; new_lhs_and_fv <- rn_rec_stmts_lhs fix_env s
- -- (C) do the right-hand-sides and thing-inside
- segs <- rn_rec_stmts bound_names new_lhs_and_fv
- cont segs
+ -- ...bring them and their fixities into scope
+ ; let bound_names = map unLoc $ collectLStmtsBinders (map fst new_lhs_and_fv)
+ ; bindLocalNamesFV_WithFixities bound_names fix_env $ do
+ -- (C) do the right-hand-sides and thing-inside
+ { segs <- rn_rec_stmts bound_names new_lhs_and_fv
+ ; (res, fvs) <- cont segs
+ ; warnUnusedLocalBinds bound_names fvs
+ ; return (res, fvs) }}
-- get all the fixity decls in any Let stmt
+collectRecStmtsFixities :: [LStmtLR RdrName RdrName] -> [LFixitySig RdrName]
collectRecStmtsFixities l =
foldr (\ s -> \acc -> case s of
- (L loc (LetStmt (HsValBinds (ValBindsIn _ sigs)))) ->
+ (L _ (LetStmt (HsValBinds (ValBindsIn _ sigs)))) ->
foldr (\ sig -> \ acc -> case sig of
(L loc (FixSig s)) -> (L loc s) : acc
_ -> acc) acc sigs
-- left-hand sides
-rn_rec_stmt_lhs :: UniqFM (Located Fixity) -- mini fixity env for the names we're about to bind
- -- these fixities need to be brought into scope with the names
+rn_rec_stmt_lhs :: MiniFixityEnv
-> LStmt RdrName
-- rename LHS, and return its FVs
-- Warning: we will only need the FreeVars below in the case of a BindStmt,
-- so we don't bother to compute it accurately in the other cases
-> RnM [(LStmtLR Name RdrName, FreeVars)]
-rn_rec_stmt_lhs fix_env (L loc (ExprStmt expr a b)) = return [(L loc (ExprStmt expr a b),
+rn_rec_stmt_lhs _ (L loc (ExprStmt expr a b)) = return [(L loc (ExprStmt expr a b),
-- this is actually correct
emptyFVs)]
return [(L loc (BindStmt pat' expr a b),
fv_pat)]
-rn_rec_stmt_lhs fix_env (L loc (LetStmt binds@(HsIPBinds _)))
- = do { addErr (badIpBinds (ptext SLIT("an mdo expression")) binds)
+rn_rec_stmt_lhs _ (L _ (LetStmt binds@(HsIPBinds _)))
+ = do { addErr (badIpBinds (ptext (sLit "an mdo expression")) binds)
; failM }
rn_rec_stmt_lhs fix_env (L loc (LetStmt (HsValBinds binds)))
emptyFVs
)]
-rn_rec_stmt_lhs fix_env (L loc (RecStmt stmts _ _ _ _)) -- Flatten Rec inside Rec
+rn_rec_stmt_lhs fix_env (L _ (RecStmt stmts _ _ _ _)) -- Flatten Rec inside Rec
= rn_rec_stmts_lhs fix_env stmts
rn_rec_stmt_lhs _ stmt@(L _ (ParStmt _)) -- Syntactically illegal in mdo
rn_rec_stmt_lhs _ stmt@(L _ (GroupStmt _ _)) -- Syntactically illegal in mdo
= pprPanic "rn_rec_stmt" (ppr stmt)
-
-rn_rec_stmts_lhs :: UniqFM (Located Fixity) -- mini fixity env for the names we're about to bind
- -- these fixities need to be brought into scope with the names
+
+rn_rec_stmt_lhs _ (L _ (LetStmt EmptyLocalBinds))
+ = panic "rn_rec_stmt LetStmt EmptyLocalBinds"
+
+rn_rec_stmts_lhs :: MiniFixityEnv
-> [LStmt RdrName]
-> RnM [(LStmtLR Name RdrName, FreeVars)]
rn_rec_stmts_lhs fix_env stmts =
-- Rename a Stmt that is inside a RecStmt (or mdo)
-- Assumes all binders are already in scope
-- Turns each stmt into a singleton Stmt
-rn_rec_stmt all_bndrs (L loc (ExprStmt expr _ _)) _
+rn_rec_stmt _ (L loc (ExprStmt expr _ _)) _
= rnLExpr expr `thenM` \ (expr', fvs) ->
lookupSyntaxName thenMName `thenM` \ (then_op, fvs1) ->
returnM [(emptyNameSet, fvs `plusFV` fvs1, emptyNameSet,
L loc (ExprStmt expr' then_op placeHolderType))]
-rn_rec_stmt all_bndrs (L loc (BindStmt pat' expr _ _)) fv_pat
+rn_rec_stmt _ (L loc (BindStmt pat' expr _ _)) fv_pat
= rnLExpr expr `thenM` \ (expr', fv_expr) ->
lookupSyntaxName bindMName `thenM` \ (bind_op, fvs1) ->
lookupSyntaxName failMName `thenM` \ (fail_op, fvs2) ->
returnM [(bndrs, fvs, bndrs `intersectNameSet` fvs,
L loc (BindStmt pat' expr' bind_op fail_op))]
-rn_rec_stmt all_bndrs (L loc (LetStmt binds@(HsIPBinds _))) _
- = do { addErr (badIpBinds (ptext SLIT("an mdo expression")) binds)
+rn_rec_stmt _ (L _ (LetStmt binds@(HsIPBinds _))) _
+ = do { addErr (badIpBinds (ptext (sLit "an mdo expression")) binds)
; failM }
rn_rec_stmt all_bndrs (L loc (LetStmt (HsValBinds binds'))) _ = do
emptyNameSet, L loc (LetStmt (HsValBinds binds')))]
-- no RecStmt case becuase they get flattened above when doing the LHSes
-rn_rec_stmt all_bndrs stmt@(L loc (RecStmt stmts _ _ _ _)) _
+rn_rec_stmt _ stmt@(L _ (RecStmt _ _ _ _ _)) _
= pprPanic "rn_rec_stmt: RecStmt" (ppr stmt)
-rn_rec_stmt all_bndrs stmt@(L _ (ParStmt _)) _ -- Syntactically illegal in mdo
+rn_rec_stmt _ stmt@(L _ (ParStmt _)) _ -- Syntactically illegal in mdo
= pprPanic "rn_rec_stmt: ParStmt" (ppr stmt)
-rn_rec_stmt all_bndrs stmt@(L _ (TransformStmt _ _ _)) _ -- Syntactically illegal in mdo
+rn_rec_stmt _ stmt@(L _ (TransformStmt _ _ _)) _ -- Syntactically illegal in mdo
= pprPanic "rn_rec_stmt: TransformStmt" (ppr stmt)
-rn_rec_stmt all_bndrs stmt@(L _ (GroupStmt _ _)) _ -- Syntactically illegal in mdo
+rn_rec_stmt _ stmt@(L _ (GroupStmt _ _)) _ -- Syntactically illegal in mdo
= pprPanic "rn_rec_stmt: GroupStmt" (ppr stmt)
+rn_rec_stmt _ (L _ (LetStmt EmptyLocalBinds)) _
+ = panic "rn_rec_stmt: LetStmt EmptyLocalBinds"
+
rn_rec_stmts :: [Name] -> [(LStmtLR Name RdrName, FreeVars)] -> RnM [Segment (LStmt Name)]
rn_rec_stmts bndrs stmts = mappM (uncurry (rn_rec_stmt bndrs)) stmts `thenM` \ segs_s ->
returnM (concat segs_s)
%************************************************************************
\begin{code}
-patSynErr e = do { addErr (sep [ptext SLIT("Pattern syntax in expression context:"),
- nest 4 (ppr e)])
- ; return (EWildPat, emptyFVs) }
+----------------------
+-- Checking when a particular Stmt is ok
+checkLetStmt :: HsStmtContext Name -> HsLocalBinds RdrName -> RnM ()
+checkLetStmt (ParStmtCtxt _) (HsIPBinds binds) = addErr (badIpBinds (ptext (sLit "a parallel list comprehension:")) binds)
+checkLetStmt _ctxt _binds = return ()
+ -- We do not allow implicit-parameter bindings in a parallel
+ -- list comprehension. I'm not sure what it might mean.
-parStmtErr = addErr (ptext SLIT("Illegal parallel list comprehension: use -XParallelListComp"))
+---------
+checkRecStmt :: HsStmtContext Name -> RnM ()
+checkRecStmt (MDoExpr {}) = return () -- Recursive stmt ok in 'mdo'
+checkRecStmt (DoExpr {}) = return () -- ..and in 'do' but only because of arrows:
+ -- proc x -> do { ...rec... }
+ -- We don't have enough context to distinguish this situation here
+ -- so we leave it to the type checker
+checkRecStmt ctxt = addErr msg
+ where
+ msg = ptext (sLit "Illegal 'rec' stmt in") <+> pprStmtContext ctxt
-transformStmtErr = addErr (ptext SLIT("Illegal transform or grouping list comprehension: use -XTransformListComp"))
-transformStmtOutsideListCompErr = addErr (ptext SLIT("Currently you may only use transform or grouping comprehensions within list comprehensions, not parallel array comprehensions"))
+---------
+checkParStmt :: HsStmtContext Name -> RnM ()
+checkParStmt _
+ = do { parallel_list_comp <- doptM Opt_ParallelListComp
+ ; checkErr parallel_list_comp msg }
+ where
+ msg = ptext (sLit "Illegal parallel list comprehension: use -XParallelListComp")
+
+---------
+checkTransformStmt :: HsStmtContext Name -> RnM ()
+checkTransformStmt ListComp -- Ensure we are really within a list comprehension because otherwise the
+ -- desugarer will break when we come to operate on a parallel array
+ = do { transform_list_comp <- doptM Opt_TransformListComp
+ ; checkErr transform_list_comp msg }
+ where
+ msg = ptext (sLit "Illegal transform or grouping list comprehension: use -XTransformListComp")
+checkTransformStmt (ParStmtCtxt ctxt) = checkTransformStmt ctxt -- Ok to nest inside a parallel comprehension
+checkTransformStmt (TransformStmtCtxt ctxt) = checkTransformStmt ctxt -- Ok to nest inside a parallel comprehension
+checkTransformStmt ctxt = addErr msg
+ where
+ msg = ptext (sLit "Illegal transform or grouping in") <+> pprStmtContext ctxt
+
+---------
+patSynErr :: HsExpr RdrName -> RnM (HsExpr Name, FreeVars)
+patSynErr e = do { addErr (sep [ptext (sLit "Pattern syntax in expression context:"),
+ nest 4 (ppr e)])
+ ; return (EWildPat, emptyFVs) }
+badIpBinds :: Outputable a => SDoc -> a -> SDoc
badIpBinds what binds
- = hang (ptext SLIT("Implicit-parameter bindings illegal in") <+> what)
+ = hang (ptext (sLit "Implicit-parameter bindings illegal in") <+> what)
2 (ppr binds)
\end{code}
-
-
projects / ghc-hetmet.git / blobdiff