#include "HsVersions.h"
import RnSource ( rnSrcDecls, rnSplice, checkTH )
-import RnBinds ( rnLocalBindsAndThen, rnValBinds,
- rnMatchGroup, trimWith )
+import RnBinds ( rnLocalBindsAndThen, rnValBindsLHS, rnValBindsRHS,
+ rnMatchGroup, makeMiniFixityEnv)
import HsSyn
import TcRnMonad
import RnEnv
import HscTypes ( availNames )
import RnNames ( getLocalDeclBinders, extendRdrEnvRn )
-import RnTypes ( rnHsTypeFVs, rnLPat, rnOverLit, rnPatsAndThen, rnLit,
- mkOpFormRn, mkOpAppRn, mkNegAppRn, checkSectionPrec,
- rnHsRecFields, checkTupSize )
+import RnTypes ( rnHsTypeFVs,
+ mkOpFormRn, mkOpAppRn, mkNegAppRn, checkSectionPrec)
+import RnPat (rnOverLit, rnPatsAndThen_LocalRightwards, rnBindPat,
+ localRecNameMaker, rnLit,
+ rnHsRecFields_Con, rnHsRecFields_Update, checkTupSize)
+import RdrName ( mkRdrUnqual )
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 )
+ negateName, thenMName, bindMName, failMName, groupWithName )
-import Name ( Name, nameOccName, nameIsLocalOrFrom )
+import Name ( Name, nameOccName, nameModule, nameIsLocalOrFrom )
import NameSet
+import UniqFM
import RdrName ( RdrName, extendLocalRdrEnv, lookupLocalRdrEnv, hideSomeUnquals )
import LoadIface ( loadInterfaceForName )
import UniqFM ( isNullUFM )
import ListSetOps ( removeDups )
import Maybes ( expectJust )
import Outputable
-import SrcLoc ( Located(..), unLoc, getLoc )
+import SrcLoc ( Located(..), unLoc, getLoc, noLoc )
import FastString
import List ( unzip4 )
= do {
opt_OverloadedStrings <- doptM Opt_OverloadedStrings
; if opt_OverloadedStrings then
- rnExpr (HsOverLit (mkHsIsString s))
+ rnExpr (HsOverLit (mkHsIsString s placeHolderType))
else -- Same as below
rnLit lit `thenM_`
returnM (HsLit lit, emptyFVs)
rnExpr (RecordCon con_id _ rbinds)
= do { conname <- lookupLocatedOccRn con_id
- ; (rbinds', fvRbinds) <- rnHsRecFields "construction" (Just conname)
- rnLExpr HsVar rbinds
+ ; (rbinds', fvRbinds) <- rnHsRecFields_Con conname rnLExpr rbinds
; return (RecordCon conname noPostTcExpr rbinds',
fvRbinds `addOneFV` unLoc conname) }
rnExpr (RecordUpd expr rbinds _ _ _)
= do { (expr', fvExpr) <- rnLExpr expr
- ; (rbinds', fvRbinds) <- rnHsRecFields "update" Nothing rnLExpr HsVar rbinds
+ ; (rbinds', fvRbinds) <- rnHsRecFields_Update rnLExpr rbinds
; return (RecordUpd expr' rbinds' [] [] [],
fvExpr `plusFV` fvRbinds) }
\begin{code}
rnExpr (HsProc pat body)
= newArrowScope $
- rnPatsAndThen ProcExpr [pat] $ \ [pat'] ->
+ rnPatsAndThen_LocalRightwards ProcExpr [pat] $ \ [pat'] ->
rnCmdTop body `thenM` \ (body',fvBody) ->
returnM (HsProc pat' body', fvBody)
= methodNamesStmts stmts `addOneFV` loopAName
methodNamesStmt (LetStmt b) = emptyFVs
methodNamesStmt (ParStmt ss) = emptyFVs
- -- ParStmt can't occur in commands, but it's not convenient to error
+methodNamesStmt (TransformStmt _ _ _) = emptyFVs
+methodNamesStmt (GroupStmt _ _) = emptyFVs
+ -- ParStmt, TransformStmt and GroupStmt can't occur in commands, but it's not convenient to error
-- here so we just do what's convenient
\end{code}
rnBracket (ExpBr e) = do { (e', fvs) <- rnLExpr e
; return (ExpBr e', fvs) }
-rnBracket (PatBr p) = do { (p', fvs) <- rnLPat p
- ; return (PatBr p', fvs) }
+
+rnBracket (PatBr p) = 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")
rnBracket (DecBr group)
- = do { gbl_env <- getGblEnv
-
- ; let gbl_env1 = gbl_env { tcg_mod = thFAKE }
- -- Note the thFAKE. The top-level names from the bracketed
- -- declarations will go into the name cache, and we don't want them to
- -- confuse the Names for the current module.
- -- By using a pretend module, thFAKE, we keep them safely out of the way.
-
- ; avails <- getLocalDeclBinders gbl_env1 group
- ; let names = concatMap availNames avails
-
- ; let new_occs = map nameOccName names
- trimmed_rdr_env = hideSomeUnquals (tcg_rdr_env gbl_env) new_occs
+ = do { gbl_env <- getGblEnv
+
+ ; let new_gbl_env = gbl_env { -- Set the module to thFAKE. The top-level names from the bracketed
+ -- declarations will go into the name cache, and we don't want them to
+ -- confuse the Names for the current module.
+ -- By using a pretend module, thFAKE, we keep them safely out of the way.
+ tcg_mod = thFAKE,
+
+ -- The emptyDUs is so that we just collect uses for this group alone
+ -- in the call to rnSrcDecls below
+ tcg_dus = emptyDUs }
+ ; setGblEnv new_gbl_env $ do {
- ; rdr_env' <- extendRdrEnvRn trimmed_rdr_env avails
-- In this situation we want to *shadow* top-level bindings.
-- foo = 1
- -- bar = [d| foo = 1|]
+ -- bar = [d| foo = 1 |]
-- If we don't shadow, we'll get an ambiguity complaint when we do
-- a lookupTopBndrRn (which uses lookupGreLocalRn) on the binder of the 'foo'
--
-- Furthermore, arguably if the splice does define foo, that should hide
-- any foo's further out
--
- -- The shadowing is acheived by the call to hideSomeUnquals, which removes
- -- the unqualified bindings of things defined by the bracket
+ -- The shadowing is acheived by calling rnSrcDecls with True as the shadowing flag
+ ; (tcg_env, group') <- rnSrcDecls True group
- ; setGblEnv (gbl_env { tcg_rdr_env = rdr_env',
- tcg_dus = emptyDUs }) $ do
- -- The emptyDUs is so that we just collect uses for this group alone
-
- { (tcg_env, group') <- rnSrcDecls group
- -- Discard the tcg_env; it contains only extra info about fixity
+ -- Discard the tcg_env; it contains only extra info about fixity
; return (DecBr group', allUses (tcg_dus tcg_env)) } }
\end{code}
-- Implements nested scopes
rnNormalStmts ctxt [] thing_inside
- = do { (thing, fvs) <- thing_inside
+ = do { (thing, fvs) <- thing_inside
; return (([],thing), fvs) }
rnNormalStmts ctxt (L loc stmt : stmts) thing_inside
- = do { ((stmt', (stmts', thing)), fvs)
- <- rnStmt ctxt stmt $
- rnNormalStmts ctxt stmts thing_inside
+ = do { ((stmt', (stmts', thing)), fvs) <- rnStmt ctxt stmt $
+ rnNormalStmts ctxt stmts thing_inside
; return (((L loc stmt' : stmts'), thing), fvs) }
-
+
+
rnStmt :: HsStmtContext Name -> Stmt RdrName
-> RnM (thing, FreeVars)
-> RnM ((Stmt Name, thing), FreeVars)
-- The binders do not scope over the expression
; (bind_op, fvs1) <- lookupSyntaxName bindMName
; (fail_op, fvs2) <- lookupSyntaxName failMName
- ; rnPatsAndThen (StmtCtxt ctxt) [pat] $ \ [pat'] -> do
+ ; rnPatsAndThen_LocalRightwards (StmtCtxt ctxt) [pat] $ \ [pat'] -> do
{ (thing, fvs3) <- thing_inside
; return ((BindStmt pat' expr' bind_op fail_op, thing),
fv_expr `plusFV` fvs1 `plusFV` fvs2 `plusFV` fvs3) }}
- -- fv_expr shouldn't really be filtered by the rnPatsAndThen
+ -- 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) }}
+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 _ _ = True
rnStmt ctxt (RecStmt rec_stmts _ _ _ _) thing_inside
- = bindLocatedLocalsRn doc (collectLStmtsBinders rec_stmts) $ \ bndrs ->
- rn_rec_stmts bndrs rec_stmts `thenM` \ segs ->
+ =
+ rn_rec_stmts_and_then rec_stmts $ \ segs ->
thing_inside `thenM` \ (thing, fvs) ->
let
segs_w_fwd_refs = addFwdRefs segs
where
doc = text "In a recursive do statement"
+rnStmt ctxt (TransformStmt (stmts, _) usingExpr maybeByExpr) thing_inside = do
+ checkIsTransformableListComp ctxt
+
+ (usingExpr', fv_usingExpr) <- rnLExpr usingExpr
+ ((stmts', binders, (maybeByExpr', thing)), fvs) <-
+ rnNormalStmtsAndFindUsedBinders (TransformStmtCtxt ctxt) stmts $ \unshadowed_bndrs -> do
+ (maybeByExpr', fv_maybeByExpr) <- rnMaybeLExpr maybeByExpr
+ (thing, fv_thing) <- thing_inside
+
+ return ((maybeByExpr', thing), fv_maybeByExpr `plusFV` fv_thing)
+
+ return ((TransformStmt (stmts', binders) usingExpr' maybeByExpr', thing), fv_usingExpr `plusFV` fvs)
+ where
+ rnMaybeLExpr Nothing = return (Nothing, emptyFVs)
+ rnMaybeLExpr (Just expr) = do
+ (expr', fv_expr) <- rnLExpr expr
+ return (Just expr', fv_expr)
+
+rnStmt ctxt (GroupStmt (stmts, _) groupByClause) thing_inside = do
+ checkIsTransformableListComp ctxt
+
+ -- We must rename the using expression in the context before the transform is begun
+ groupByClauseAction <-
+ case groupByClause of
+ GroupByNothing usingExpr -> do
+ (usingExpr', fv_usingExpr) <- rnLExpr usingExpr
+ (return . return) (GroupByNothing usingExpr', fv_usingExpr)
+ GroupBySomething eitherUsingExpr byExpr -> do
+ (eitherUsingExpr', fv_eitherUsingExpr) <-
+ case eitherUsingExpr of
+ Right _ -> return (Right $ HsVar groupWithName, unitNameSet groupWithName)
+ Left usingExpr -> do
+ (usingExpr', fv_usingExpr) <- rnLExpr usingExpr
+ return (Left usingExpr', fv_usingExpr)
+
+ return $ do
+ (byExpr', fv_byExpr) <- rnLExpr byExpr
+ return (GroupBySomething eitherUsingExpr' byExpr', fv_eitherUsingExpr `plusFV` fv_byExpr)
+
+ -- We only use rnNormalStmtsAndFindUsedBinders to get unshadowed_bndrs, so
+ -- perhaps we could refactor this to use rnNormalStmts directly?
+ ((stmts', _, (groupByClause', usedBinderMap, thing)), fvs) <-
+ rnNormalStmtsAndFindUsedBinders (TransformStmtCtxt ctxt) stmts $ \unshadowed_bndrs -> do
+ (groupByClause', fv_groupByClause) <- groupByClauseAction
+
+ unshadowed_bndrs' <- mapM newLocalName unshadowed_bndrs
+ let binderMap = zip unshadowed_bndrs unshadowed_bndrs'
+
+ -- Bind the "thing" inside a context where we have REBOUND everything
+ -- bound by the statements before the group. This is necessary since after
+ -- the grouping the same identifiers actually have different meanings
+ -- i.e. they refer to lists not singletons!
+ (thing, fv_thing) <- bindLocalNames unshadowed_bndrs' thing_inside
+
+ -- We remove entries from the binder map that are not used in the thing_inside.
+ -- We can then use that usage information to ensure that the free variables do
+ -- not contain the things we just bound, but do contain the things we need to
+ -- make those bindings (i.e. the corresponding non-listy variables)
+
+ -- Note that we also retain those entries which have an old binder in our
+ -- own free variables (the using or by expression). This is because this map
+ -- is reused in the desugarer to create the type to bind from the statements
+ -- that occur before this one. If the binders we need are not in the map, they
+ -- will never get bound into our desugared expression and hence the simplifier
+ -- crashes as we refer to variables that don't exist!
+ let usedBinderMap = filter
+ (\(old_binder, new_binder) ->
+ (new_binder `elemNameSet` fv_thing) ||
+ (old_binder `elemNameSet` fv_groupByClause)) binderMap
+ (usedOldBinders, usedNewBinders) = unzip usedBinderMap
+ real_fv_thing = (delListFromNameSet fv_thing usedNewBinders) `plusFV` (mkNameSet usedOldBinders)
+
+ return ((groupByClause', usedBinderMap, thing), fv_groupByClause `plusFV` real_fv_thing)
+
+ 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
- ; orig_lcl_env <- getLocalRdrEnv
- ; ((segs',thing), fvs) <- go orig_lcl_env [] segs
+ ; ((segs', thing), fvs) <- rnParallelStmts (ParStmtCtxt ctxt) segs thing_inside
; return ((ParStmt segs', thing), fvs) }
+
+
+rnNormalStmtsAndFindUsedBinders :: HsStmtContext Name
+ -> [LStmt RdrName]
+ -> ([Name] -> RnM (thing, FreeVars))
+ -> RnM (([LStmt Name], [Name], thing), FreeVars)
+rnNormalStmtsAndFindUsedBinders ctxt stmts thing_inside = do
+ ((stmts', (used_bndrs, inner_thing)), fvs) <- rnNormalStmts ctxt stmts $ do
+ -- Find the Names that are bound by stmts that
+ -- by assumption we have just renamed
+ local_env <- getLocalRdrEnv
+ let
+ stmts_binders = collectLStmtsBinders stmts
+ bndrs = map (expectJust "rnStmt"
+ . lookupLocalRdrEnv local_env
+ . unLoc) stmts_binders
+
+ -- If shadow, we'll look up (Unqual x) twice, getting
+ -- the second binding both times, which is the
+ -- one we want
+ unshadowed_bndrs = nub bndrs
+
+ -- Typecheck the thing inside, passing on all
+ -- the Names bound before it for its information
+ (thing, fvs) <- thing_inside unshadowed_bndrs
+
+ -- Figure out which of the bound names are used
+ -- after the statements we renamed
+ let used_bndrs = filter (`elemNameSet` fvs) bndrs
+ return ((used_bndrs, thing), fvs)
+
+ -- Flatten the tuple returned by the above call a bit!
+ return ((stmts', used_bndrs, inner_thing), fvs)
+
+
+rnParallelStmts ctxt segs thing_inside = do
+ orig_lcl_env <- getLocalRdrEnv
+ go orig_lcl_env [] segs
+ where
+ go orig_lcl_env bndrs [] = do
+ let (bndrs', dups) = removeDups cmpByOcc bndrs
+ inner_env = extendLocalRdrEnv orig_lcl_env bndrs'
+
+ mappM dupErr dups
+ (thing, fvs) <- setLocalRdrEnv inner_env thing_inside
+ return (([], thing), fvs)
+
+ go orig_lcl_env bndrs_so_far ((stmts, _) : segs) = do
+ ((stmts', bndrs, (segs', thing)), fvs) <- rnNormalStmtsAndFindUsedBinders ctxt stmts $ \new_bndrs -> do
+ -- Typecheck the thing inside, passing on all
+ -- the Names bound, but separately; revert the envt
+ setLocalRdrEnv orig_lcl_env $ do
+ go orig_lcl_env (new_bndrs ++ bndrs_so_far) segs
+
+ let seg' = (stmts', bndrs)
+ 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:")
+ <+> 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
--- type ParSeg id = [([LStmt id], [id])]
--- go :: NameSet -> [ParSeg RdrName]
--- -> RnM (([ParSeg Name], thing), FreeVars)
-
- go orig_lcl_env bndrs []
- = do { let { (bndrs', dups) = removeDups cmpByOcc bndrs
- ; inner_env = extendLocalRdrEnv orig_lcl_env bndrs' }
- ; mappM dupErr dups
- ; (thing, fvs) <- setLocalRdrEnv inner_env thing_inside
- ; return (([], thing), fvs) }
-
- go orig_lcl_env bndrs_so_far ((stmts, _) : segs)
- = do { ((stmts', (bndrs, segs', thing)), fvs)
- <- rnNormalStmts par_ctxt stmts $ do
- { -- Find the Names that are bound by stmts
- lcl_env <- getLocalRdrEnv
- ; let { rdr_bndrs = collectLStmtsBinders stmts
- ; bndrs = map ( expectJust "rnStmt"
- . lookupLocalRdrEnv lcl_env
- . unLoc) rdr_bndrs
- ; new_bndrs = nub bndrs ++ bndrs_so_far
- -- The nub is because there might be shadowing
- -- x <- e1; x <- e2
- -- So we'll look up (Unqual x) twice, getting
- -- the second binding both times, which is the
- } -- one we want
-
- -- Typecheck the thing inside, passing on all
- -- the Names bound, but separately; revert the envt
- ; ((segs', thing), fvs) <- setLocalRdrEnv orig_lcl_env $
- go orig_lcl_env new_bndrs segs
-
- -- Figure out which of the bound names are used
- ; let used_bndrs = filter (`elemNameSet` fvs) bndrs
- ; return ((used_bndrs, segs', thing), fvs) }
-
- ; let seg' = (stmts', bndrs)
- ; return (((seg':segs'), thing),
- delListFromNameSet fvs bndrs) }
-
- par_ctxt = ParStmtCtxt ctxt
-
- cmpByOcc n1 n2 = nameOccName n1 `compare` nameOccName n2
- dupErr vs = addErr (ptext SLIT("Duplicate binding in parallel list comprehension for:")
- <+> quotes (ppr (head vs)))
+ notParallelArray PArrComp = False
+ notParallelArray _ = True
+
\end{code}
----------------------------------------------------
+
rnMDoStmts :: [LStmt RdrName]
-> RnM (thing, FreeVars)
-> RnM (([LStmt Name], thing), FreeVars)
rnMDoStmts stmts thing_inside
- = -- Step1: bring all the binders of the mdo into scope
- -- Remember that this also removes the binders from the
- -- finally-returned free-vars
- bindLocatedLocalsRn doc (collectLStmtsBinders stmts) $ \ bndrs ->
- do {
- -- Step 2: Rename each individual stmt, making a
- -- singleton segment. At this stage the FwdRefs field
- -- isn't finished: it's empty for all except a BindStmt
- -- for which it's the fwd refs within the bind itself
- -- (This set may not be empty, because we're in a recursive
- -- context.)
- segs <- rn_rec_stmts bndrs stmts
+ = -- Step1: Bring all the binders of the mdo into scope
+ -- (Remember that this also removes the binders from the
+ -- finally-returned free-vars.)
+ -- And rename each individual stmt, making a
+ -- singleton segment. At this stage the FwdRefs field
+ -- isn't finished: it's empty for all except a BindStmt
+ -- for which it's the fwd refs within the bind itself
+ -- (This set may not be empty, because we're in a recursive
+ -- context.)
+ rn_rec_stmts_and_then stmts $ \ segs -> do {
; (thing, fvs_later) <- thing_inside
; let
- -- Step 3: Fill in the fwd refs.
+ -- Step 2: Fill in the fwd refs.
-- The segments are all singletons, but their fwd-ref
-- field mentions all the things used by the segment
-- that are bound after their use
segs_w_fwd_refs = addFwdRefs segs
- -- Step 4: Group together the segments to make bigger segments
+ -- Step 3: Group together the segments to make bigger segments
-- Invariant: in the result, no segment uses a variable
-- bound in a later segment
grouped_segs = glomSegments segs_w_fwd_refs
- -- Step 5: Turn the segments into Stmts
+ -- Step 4: Turn the segments into Stmts
-- Use RecStmt when and only when there are fwd refs
-- Also gather up the uses from the end towards the
-- start, so we can tell the RecStmt which things are
doc = text "In a recursive mdo-expression"
---------------------------------------------
-rn_rec_stmts :: [Name] -> [LStmt RdrName] -> RnM [Segment (LStmt Name)]
-rn_rec_stmts bndrs stmts = mappM (rn_rec_stmt bndrs) stmts `thenM` \ segs_s ->
- returnM (concat segs_s)
-----------------------------------------------------
-rn_rec_stmt :: [Name] -> LStmt RdrName -> RnM [Segment (LStmt Name)]
+-- wrapper that does both the left- and right-hand sides
+rn_rec_stmts_and_then :: [LStmt RdrName]
+ -- assumes that the FreeVars returned includes
+ -- 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
+
+ -- 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
+
+ -- (C) do the right-hand-sides and thing-inside
+ segs <- rn_rec_stmts bound_names new_lhs_and_fv
+ cont segs
+
+
+-- get all the fixity decls in any Let stmt
+collectRecStmtsFixities l =
+ foldr (\ s -> \acc -> case s of
+ (L loc (LetStmt (HsValBinds (ValBindsIn _ sigs)))) ->
+ foldr (\ sig -> \ acc -> case sig of
+ (L loc (FixSig s)) -> (L loc s) : acc
+ _ -> acc) acc sigs
+ _ -> acc) [] l
+
+-- 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
+ -> 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),
+ -- this is actually correct
+ emptyFVs)]
+
+rn_rec_stmt_lhs fix_env (L loc (BindStmt pat expr a b))
+ = do
+ -- should the ctxt be MDo instead?
+ (pat', fv_pat) <- rnBindPat (localRecNameMaker fix_env) pat
+ 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)
+ ; failM }
+
+rn_rec_stmt_lhs fix_env (L loc (LetStmt (HsValBinds binds)))
+ = do binds' <- rnValBindsLHS fix_env binds
+ return [(L loc (LetStmt (HsValBinds binds')),
+ -- Warning: this is bogus; see function invariant
+ emptyFVs
+ )]
+
+rn_rec_stmt_lhs fix_env (L loc (RecStmt stmts _ _ _ _)) -- Flatten Rec inside Rec
+ = rn_rec_stmts_lhs fix_env stmts
+
+rn_rec_stmt_lhs _ stmt@(L _ (ParStmt _)) -- Syntactically illegal in mdo
+ = pprPanic "rn_rec_stmt" (ppr stmt)
+
+rn_rec_stmt_lhs _ stmt@(L _ (TransformStmt _ _ _)) -- Syntactically illegal in mdo
+ = pprPanic "rn_rec_stmt" (ppr stmt)
+
+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
+ -> [LStmt RdrName]
+ -> RnM [(LStmtLR Name RdrName, FreeVars)]
+rn_rec_stmts_lhs fix_env stmts =
+ let boundNames = collectLStmtsBinders stmts
+ doc = text "In a recursive mdo-expression"
+ in do
+ -- First do error checking: we need to check for dups here because we
+ -- don't bind all of the variables from the Stmt at once
+ -- with bindLocatedLocals.
+ checkDupNames doc boundNames
+ mappM (rn_rec_stmt_lhs fix_env) stmts `thenM` \ ls -> returnM (concat ls)
+
+
+-- right-hand-sides
+
+rn_rec_stmt :: [Name] -> LStmtLR Name RdrName -> FreeVars -> RnM [Segment (LStmt Name)]
-- 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 _ _))
- = rnLExpr expr `thenM` \ (expr', fvs) ->
+rn_rec_stmt all_bndrs (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 _ _))
+rn_rec_stmt all_bndrs (L loc (BindStmt pat' expr _ _)) fv_pat
= rnLExpr expr `thenM` \ (expr', fv_expr) ->
- rnLPat pat `thenM` \ (pat', fv_pat) ->
lookupSyntaxName bindMName `thenM` \ (bind_op, fvs1) ->
lookupSyntaxName failMName `thenM` \ (fail_op, fvs2) ->
let
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 _)))
+rn_rec_stmt all_bndrs (L loc (LetStmt binds@(HsIPBinds _))) _
= do { addErr (badIpBinds (ptext SLIT("an mdo expression")) binds)
; failM }
-rn_rec_stmt all_bndrs (L loc (LetStmt (HsValBinds binds)))
- = rnValBinds (trimWith all_bndrs) binds `thenM` \ (binds', du_binds) ->
- returnM [(duDefs du_binds, duUses du_binds,
- emptyNameSet, L loc (LetStmt (HsValBinds binds')))]
+rn_rec_stmt all_bndrs (L loc (LetStmt (HsValBinds binds'))) _ = do
+ (binds', du_binds) <-
+ -- fixities and unused are handled above in rn_rec_stmts_and_then
+ rnValBindsRHS all_bndrs binds'
+ returnM [(duDefs du_binds, duUses du_binds,
+ emptyNameSet, L loc (LetStmt (HsValBinds binds')))]
-rn_rec_stmt all_bndrs (L loc (RecStmt stmts _ _ _ _)) -- Flatten Rec inside Rec
- = rn_rec_stmts all_bndrs stmts
+-- no RecStmt case becuase they get flattened above when doing the LHSes
+rn_rec_stmt all_bndrs stmt@(L loc (RecStmt stmts _ _ _ _)) _
+ = pprPanic "rn_rec_stmt: RecStmt" (ppr stmt)
-rn_rec_stmt all_bndrs stmt@(L _ (ParStmt _)) -- Syntactically illegal in mdo
- = pprPanic "rn_rec_stmt" (ppr stmt)
+rn_rec_stmt all_bndrs 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
+ = pprPanic "rn_rec_stmt: TransformStmt" (ppr stmt)
+
+rn_rec_stmt all_bndrs stmt@(L _ (GroupStmt _ _)) _ -- Syntactically illegal in mdo
+ = pprPanic "rn_rec_stmt: GroupStmt" (ppr stmt)
+
+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)
---------------------------------------------
addFwdRefs :: [Segment a] -> [Segment a]
nest 4 (ppr e)])
; return (EWildPat, emptyFVs) }
+
parStmtErr = addErr (ptext SLIT("Illegal parallel list comprehension: use -XParallelListComp"))
+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"))
+
badIpBinds what binds
= hang (ptext SLIT("Implicit-parameter bindings illegal in") <+> what)
2 (ppr binds)
projects / ghc-hetmet.git / blobdiff