%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnExpr]{Renaming of expressions}
Basically dependency analysis.
-Handles @Match@, @GRHSsAndBinds@, @HsExpr@, and @Qual@ datatypes. In
+Handles @Match@, @GRHSs@, @HsExpr@, and @Qualifier@ datatypes. In
general, all of these functions return a renamed thing, and a set of
free variables.
\begin{code}
-#include "HsVersions.h"
-
module RnExpr (
- rnMatch, rnGRHSsAndBinds, rnPat,
+ rnMatch, rnGRHSs, rnExpr, rnExprs, rnStmts,
checkPrecMatch
) where
-IMP_Ubiq()
-IMPORT_DELOOPER(RnLoop) -- break the RnPass/RnExpr/RnBinds loops
+#include "HsVersions.h"
+
+import {-# SOURCE #-} RnSource ( rnSrcDecls, rnBindsAndThen, rnBinds )
+
+-- RnSource imports RnBinds.rnTopMonoBinds, RnExpr.rnExpr
+-- RnBinds imports RnExpr.rnMatch, etc
+-- RnExpr imports [boot] RnSource.rnSrcDecls, RnSource.rnBinds
import HsSyn
import RdrHsSyn
import RnHsSyn
-import RnMonad
-
-import ErrUtils ( addErrLoc, addShortErrLocLine )
-import Name ( isLocallyDefinedName, pprSym, Name, RdrName )
-import Pretty
-import UniqFM ( lookupUFM, ufmToList{-ToDo:rm-} )
-import UniqSet ( emptyUniqSet, unitUniqSet,
- unionUniqSets, unionManyUniqSets,
- UniqSet(..)
- )
-import Util ( Ord3(..), removeDups, panic )
+import TcRnMonad
+import RnEnv
+import RnNames ( importsFromLocalDecls )
+import RnTypes ( rnHsTypeFVs, rnPat, litFVs, rnOverLit, rnPatsAndThen,
+ dupFieldErr, precParseErr, sectionPrecErr, patSigErr, checkTupSize )
+import CmdLineOpts ( DynFlag(..), opt_IgnoreAsserts )
+import BasicTypes ( Fixity(..), FixityDirection(..), IPName(..),
+ defaultFixity, negateFixity, compareFixity )
+import PrelNames ( hasKey, assertIdKey,
+ foldrName, buildName,
+ cCallableClassName, cReturnableClassName,
+ enumClassName,
+ splitName, fstName, sndName, ioDataConName,
+ replicatePName, mapPName, filterPName,
+ crossPName, zipPName, toPName,
+ enumFromToPName, enumFromThenToPName, assertErrorName,
+ negateName, monadNames, mfixName )
+import Name ( Name, nameOccName )
+import NameSet
+import UnicodeUtil ( stringToUtf8 )
+import UniqFM ( isNullUFM )
+import UniqSet ( emptyUniqSet )
+import Util ( isSingleton )
+import List ( intersectBy, unzip4 )
+import ListSetOps ( removeDups )
+import Outputable
+import FastString
\end{code}
-*********************************************************
-* *
-\subsection{Patterns}
-* *
-*********************************************************
-
-\begin{code}
-rnPat :: RdrNamePat -> RnM_Fixes s RenamedPat
-
-rnPat WildPatIn = returnRn WildPatIn
-
-rnPat (VarPatIn name)
- = lookupValue name `thenRn` \ vname ->
- returnRn (VarPatIn vname)
-
-rnPat (LitPatIn n) = returnRn (LitPatIn n)
-
-rnPat (LazyPatIn pat)
- = rnPat pat `thenRn` \ pat' ->
- returnRn (LazyPatIn pat')
-
-rnPat (AsPatIn name pat)
- = rnPat pat `thenRn` \ pat' ->
- lookupValue name `thenRn` \ vname ->
- returnRn (AsPatIn vname pat')
-
-rnPat (ConPatIn con pats)
- = lookupConstr con `thenRn` \ con' ->
- mapRn rnPat pats `thenRn` \ patslist ->
- returnRn (ConPatIn con' patslist)
-
-rnPat (ConOpPatIn pat1 con pat2)
- = lookupConstr con `thenRn` \ con' ->
- rnPat pat1 `thenRn` \ pat1' ->
- rnPat pat2 `thenRn` \ pat2' ->
- precParsePat (ConOpPatIn pat1' con' pat2')
-
-rnPat neg@(NegPatIn pat)
- = getSrcLocRn `thenRn` \ src_loc ->
- addErrIfRn (not (valid_neg_pat pat)) (negPatErr neg src_loc)
- `thenRn_`
- rnPat pat `thenRn` \ pat' ->
- returnRn (NegPatIn pat')
- where
- valid_neg_pat (LitPatIn (HsInt _)) = True
- valid_neg_pat (LitPatIn (HsFrac _)) = True
- valid_neg_pat _ = False
-
-rnPat (ParPatIn pat)
- = rnPat pat `thenRn` \ pat' ->
- returnRn (ParPatIn pat')
-
-rnPat (ListPatIn pats)
- = mapRn rnPat pats `thenRn` \ patslist ->
- returnRn (ListPatIn patslist)
-
-rnPat (TuplePatIn pats)
- = mapRn rnPat pats `thenRn` \ patslist ->
- returnRn (TuplePatIn patslist)
-
-rnPat (RecPatIn con rpats)
- = lookupConstr con `thenRn` \ con' ->
- rnRpats rpats `thenRn` \ rpats' ->
- returnRn (RecPatIn con' rpats')
-\end{code}
-
************************************************************************
* *
\subsection{Match}
************************************************************************
\begin{code}
-rnMatch :: RdrNameMatch -> RnM_Fixes s (RenamedMatch, FreeVars)
-
-rnMatch match
- = getSrcLocRn `thenRn` \ src_loc ->
- newLocalNames "variable in pattern"
- (binders `zip` repeat src_loc) `thenRn` \ new_binders ->
- extendSS2 new_binders (rnMatch_aux match)
+rnMatch :: HsMatchContext Name -> RdrNameMatch -> RnM (RenamedMatch, FreeVars)
+
+rnMatch ctxt match@(Match pats maybe_rhs_sig grhss)
+ = addSrcLoc (getMatchLoc match) $
+
+ -- Deal with the rhs type signature
+ bindPatSigTyVars rhs_sig_tys $
+ doptM Opt_GlasgowExts `thenM` \ opt_GlasgowExts ->
+ (case maybe_rhs_sig of
+ Nothing -> returnM (Nothing, emptyFVs)
+ Just ty | opt_GlasgowExts -> rnHsTypeFVs doc_sig ty `thenM` \ (ty', ty_fvs) ->
+ returnM (Just ty', ty_fvs)
+ | otherwise -> addErr (patSigErr ty) `thenM_`
+ returnM (Nothing, emptyFVs)
+ ) `thenM` \ (maybe_rhs_sig', ty_fvs) ->
+
+ -- Now the main event
+ rnPatsAndThen ctxt pats $ \ pats' ->
+ rnGRHSs ctxt grhss `thenM` \ (grhss', grhss_fvs) ->
+
+ returnM (Match pats' maybe_rhs_sig' grhss', grhss_fvs `plusFV` ty_fvs)
+ -- The bindPatSigTyVars and rnPatsAndThen will remove the bound FVs
where
- binders = collect_binders match
-
- collect_binders :: RdrNameMatch -> [RdrName]
-
- collect_binders (GRHSMatch _) = []
- collect_binders (PatMatch pat match)
- = collectPatBinders pat ++ collect_binders match
-
-rnMatch_aux (PatMatch pat match)
- = rnPat pat `thenRn` \ pat' ->
- rnMatch_aux match `thenRn` \ (match', fvMatch) ->
- returnRn (PatMatch pat' match', fvMatch)
-
-rnMatch_aux (GRHSMatch grhss_and_binds)
- = rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', fvs) ->
- returnRn (GRHSMatch grhss_and_binds', fvs)
+ rhs_sig_tys = case maybe_rhs_sig of
+ Nothing -> []
+ Just ty -> [ty]
+ doc_sig = text "In a result type-signature"
\end{code}
+
%************************************************************************
%* *
-\subsubsection{Guarded right-hand sides (GRHSsAndBinds)}
+\subsubsection{Guarded right-hand sides (GRHSs)}
%* *
%************************************************************************
\begin{code}
-rnGRHSsAndBinds :: RdrNameGRHSsAndBinds -> RnM_Fixes s (RenamedGRHSsAndBinds, FreeVars)
+rnGRHSs :: HsMatchContext Name -> RdrNameGRHSs -> RnM (RenamedGRHSs, FreeVars)
+
+rnGRHSs ctxt (GRHSs grhss binds _)
+ = rnBindsAndThen binds $ \ binds' ->
+ mapFvRn (rnGRHS ctxt) grhss `thenM` \ (grhss', fvGRHSs) ->
+ returnM (GRHSs grhss' binds' placeHolderType, fvGRHSs)
-rnGRHSsAndBinds (GRHSsAndBindsIn grhss binds)
- = rnBinds binds `thenRn` \ (binds', fvBinds, scope) ->
- extendSS2 scope (rnGRHSs grhss) `thenRn` \ (grhss', fvGRHS) ->
- returnRn (GRHSsAndBindsIn grhss' binds', fvBinds `unionUniqSets` fvGRHS)
+rnGRHS ctxt (GRHS guarded locn)
+ = addSrcLoc locn $
+ doptM Opt_GlasgowExts `thenM` \ opt_GlasgowExts ->
+ checkM (opt_GlasgowExts || is_standard_guard guarded)
+ (addWarn (nonStdGuardErr guarded)) `thenM_`
+
+ rnStmts (PatGuard ctxt) guarded `thenM` \ (guarded', fvs) ->
+ returnM (GRHS guarded' locn, fvs)
where
- rnGRHSs [] = returnRn ([], emptyUniqSet)
-
- rnGRHSs (grhs:grhss)
- = rnGRHS grhs `thenRn` \ (grhs', fvs) ->
- rnGRHSs grhss `thenRn` \ (grhss', fvss) ->
- returnRn (grhs' : grhss', fvs `unionUniqSets` fvss)
-
- rnGRHS (GRHS guard expr locn)
- = pushSrcLocRn locn $
- rnExpr guard `thenRn` \ (guard', fvsg) ->
- rnExpr expr `thenRn` \ (expr', fvse) ->
- returnRn (GRHS guard' expr' locn, fvsg `unionUniqSets` fvse)
-
- rnGRHS (OtherwiseGRHS expr locn)
- = pushSrcLocRn locn $
- rnExpr expr `thenRn` \ (expr', fvs) ->
- returnRn (OtherwiseGRHS expr' locn, fvs)
+ -- Standard Haskell 1.4 guards are just a single boolean
+ -- expression, rather than a list of qualifiers as in the
+ -- Glasgow extension
+ is_standard_guard [ResultStmt _ _] = True
+ is_standard_guard [ExprStmt _ _ _, ResultStmt _ _] = True
+ is_standard_guard other = False
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-rnExprs :: [RdrNameHsExpr] -> RnM_Fixes s ([RenamedHsExpr], FreeVars)
-
-rnExprs [] = returnRn ([], emptyUniqSet)
+rnExprs :: [RdrNameHsExpr] -> RnM ([RenamedHsExpr], FreeVars)
+rnExprs ls = rnExprs' ls emptyUniqSet
+ where
+ rnExprs' [] acc = returnM ([], acc)
+ rnExprs' (expr:exprs) acc
+ = rnExpr expr `thenM` \ (expr', fvExpr) ->
+
+ -- Now we do a "seq" on the free vars because typically it's small
+ -- or empty, especially in very long lists of constants
+ let
+ acc' = acc `plusFV` fvExpr
+ in
+ (grubby_seqNameSet acc' rnExprs') exprs acc' `thenM` \ (exprs', fvExprs) ->
+ returnM (expr':exprs', fvExprs)
-rnExprs (expr:exprs)
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
- rnExprs exprs `thenRn` \ (exprs', fvExprs) ->
- returnRn (expr':exprs', fvExpr `unionUniqSets` fvExprs)
+-- Grubby little function to do "seq" on namesets; replace by proper seq when GHC can do seq
+grubby_seqNameSet ns result | isNullUFM ns = result
+ | otherwise = result
\end{code}
-Variables. We look up the variable and return the resulting name. The
-interesting question is what the free-variable set should be. We
-don't want to return imported or prelude things as free vars. So we
-look at the RnName returned from the lookup, and make it part of the
-free-var set iff if it's a LocallyDefined RnName.
-
-ToDo: what about RnClassOps ???
-\end{itemize}
+Variables. We look up the variable and return the resulting name.
\begin{code}
-fv_set vname@(RnName n) | isLocallyDefinedName n
- = unitUniqSet vname
-fv_set _ = emptyUniqSet
-
-
-rnExpr :: RdrNameHsExpr -> RnM_Fixes s (RenamedHsExpr, FreeVars)
+rnExpr :: RdrNameHsExpr -> RnM (RenamedHsExpr, FreeVars)
rnExpr (HsVar v)
- = lookupValue v `thenRn` \ vname ->
- returnRn (HsVar vname, fv_set vname)
-
-rnExpr (HsLit lit)
- = returnRn (HsLit lit, emptyUniqSet)
+ = lookupOccRn v `thenM` \ name ->
+ if name `hasKey` assertIdKey && not opt_IgnoreAsserts then
+ -- We expand it to (GHC.Err.assertError location_string)
+ mkAssertErrorExpr
+ else
+ -- The normal case. Even if the Id was 'assert', if we are
+ -- ignoring assertions we leave it as GHC.Base.assert;
+ -- this function just ignores its first arg.
+ returnM (HsVar name, unitFV name)
+
+rnExpr (HsIPVar v)
+ = newIPName v `thenM` \ name ->
+ let
+ fvs = case name of
+ Linear _ -> mkFVs [splitName, fstName, sndName]
+ Dupable _ -> emptyFVs
+ in
+ returnM (HsIPVar name, fvs)
+
+rnExpr (HsLit lit)
+ = litFVs lit `thenM` \ fvs ->
+ returnM (HsLit lit, fvs)
+
+rnExpr (HsOverLit lit)
+ = rnOverLit lit `thenM` \ (lit', fvs) ->
+ returnM (HsOverLit lit', fvs)
rnExpr (HsLam match)
- = rnMatch match `thenRn` \ (match', fvMatch) ->
- returnRn (HsLam match', fvMatch)
+ = rnMatch LambdaExpr match `thenM` \ (match', fvMatch) ->
+ returnM (HsLam match', fvMatch)
rnExpr (HsApp fun arg)
- = rnExpr fun `thenRn` \ (fun',fvFun) ->
- rnExpr arg `thenRn` \ (arg',fvArg) ->
- returnRn (HsApp fun' arg', fvFun `unionUniqSets` fvArg)
-
-rnExpr (OpApp e1 op e2)
- = rnExpr e1 `thenRn` \ (e1', fvs_e1) ->
- rnExpr op `thenRn` \ (op', fvs_op) ->
- rnExpr e2 `thenRn` \ (e2', fvs_e2) ->
- precParseExpr (OpApp e1' op' e2') `thenRn` \ exp ->
- returnRn (exp, (fvs_op `unionUniqSets` fvs_e1) `unionUniqSets` fvs_e2)
-
-rnExpr (NegApp e n)
- = rnExpr e `thenRn` \ (e', fvs_e) ->
- rnExpr n `thenRn` \ (n', fvs_n) ->
- returnRn (NegApp e' n', fvs_e `unionUniqSets` fvs_n)
+ = rnExpr fun `thenM` \ (fun',fvFun) ->
+ rnExpr arg `thenM` \ (arg',fvArg) ->
+ returnM (HsApp fun' arg', fvFun `plusFV` fvArg)
+
+rnExpr (OpApp e1 op _ e2)
+ = rnExpr e1 `thenM` \ (e1', fv_e1) ->
+ rnExpr e2 `thenM` \ (e2', fv_e2) ->
+ rnExpr op `thenM` \ (op'@(HsVar op_name), fv_op) ->
+
+ -- Deal with fixity
+ -- When renaming code synthesised from "deriving" declarations
+ -- we're in Interface mode, and we should ignore fixity; assume
+ -- that the deriving code generator got the association correct
+ -- Don't even look up the fixity when in interface mode
+ getModeRn `thenM` \ mode ->
+ (if isInterfaceMode mode
+ then returnM (OpApp e1' op' defaultFixity e2')
+ else lookupFixityRn op_name `thenM` \ fixity ->
+ mkOpAppRn e1' op' fixity e2'
+ ) `thenM` \ final_e ->
+
+ returnM (final_e,
+ fv_e1 `plusFV` fv_op `plusFV` fv_e2)
+
+rnExpr (NegApp e _)
+ = rnExpr e `thenM` \ (e', fv_e) ->
+ lookupSyntaxName negateName `thenM` \ (neg_name, fv_neg) ->
+ mkNegAppRn e' neg_name `thenM` \ final_e ->
+ returnM (final_e, fv_e `plusFV` fv_neg)
rnExpr (HsPar e)
- = rnExpr e `thenRn` \ (e', fvs_e) ->
- returnRn (HsPar e', fvs_e)
+ = rnExpr e `thenM` \ (e', fvs_e) ->
+ returnM (HsPar e', fvs_e)
+
+-- Template Haskell extensions
+-- Don't ifdef-GHCI them because we want to fail gracefully
+-- (not with an rnExpr crash) in a stage-1 compiler.
+rnExpr e@(HsBracket br_body loc)
+ = addSrcLoc loc $
+ checkTH e "bracket" `thenM_`
+ rnBracket br_body `thenM` \ (body', fvs_e) ->
+ returnM (HsBracket body' loc, fvs_e `plusFV` thProxyName)
+
+rnExpr e@(HsSplice n splice loc)
+ = addSrcLoc loc $
+ checkTH e "splice" `thenM_`
+ newLocalsRn [(n,loc)] `thenM` \ [n'] ->
+ rnExpr splice `thenM` \ (splice', fvs_e) ->
+ returnM (HsSplice n' splice' loc, fvs_e `plusFV` thProxyName)
+
+rnExpr e@(HsReify (Reify flavour name))
+ = checkTH e "reify" `thenM_`
+ lookupGlobalOccRn name `thenM` \ name' ->
+ -- For now, we can only reify top-level things
+ returnM (HsReify (Reify flavour name'), unitFV name' `plusFV` thProxyName)
+
+rnExpr section@(SectionL expr op)
+ = rnExpr expr `thenM` \ (expr', fvs_expr) ->
+ rnExpr op `thenM` \ (op', fvs_op) ->
+ checkSectionPrec InfixL section op' expr' `thenM_`
+ returnM (SectionL expr' op', fvs_op `plusFV` fvs_expr)
+
+rnExpr section@(SectionR op expr)
+ = rnExpr op `thenM` \ (op', fvs_op) ->
+ rnExpr expr `thenM` \ (expr', fvs_expr) ->
+ checkSectionPrec InfixR section op' expr' `thenM_`
+ returnM (SectionR op' expr', fvs_op `plusFV` fvs_expr)
+
+rnExpr (HsCCall fun args may_gc is_casm _)
+ -- Check out the comment on RnIfaces.getNonWiredDataDecl about ccalls
+ = rnExprs args `thenM` \ (args', fvs_args) ->
+ returnM (HsCCall fun args' may_gc is_casm placeHolderType,
+ fvs_args `plusFV` mkFVs [cCallableClassName,
+ cReturnableClassName,
+ ioDataConName])
+
+rnExpr (HsSCC lbl expr)
+ = rnExpr expr `thenM` \ (expr', fvs_expr) ->
+ returnM (HsSCC lbl expr', fvs_expr)
-rnExpr (SectionL expr op)
- = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
- rnExpr op `thenRn` \ (op', fvs_op) ->
- returnRn (SectionL expr' op', fvs_op `unionUniqSets` fvs_expr)
-
-rnExpr (SectionR op expr)
- = rnExpr op `thenRn` \ (op', fvs_op) ->
- rnExpr expr `thenRn` \ (expr', fvs_expr) ->
- returnRn (SectionR op' expr', fvs_op `unionUniqSets` fvs_expr)
+rnExpr (HsCase expr ms src_loc)
+ = addSrcLoc src_loc $
+ rnExpr expr `thenM` \ (new_expr, e_fvs) ->
+ mapFvRn (rnMatch CaseAlt) ms `thenM` \ (new_ms, ms_fvs) ->
+ returnM (HsCase new_expr new_ms src_loc, e_fvs `plusFV` ms_fvs)
-rnExpr (CCall fun args may_gc is_casm fake_result_ty)
- = rnExprs args `thenRn` \ (args', fvs_args) ->
- returnRn (CCall fun args' may_gc is_casm fake_result_ty, fvs_args)
+rnExpr (HsLet binds expr)
+ = rnBindsAndThen binds $ \ binds' ->
+ rnExpr expr `thenM` \ (expr',fvExpr) ->
+ returnM (HsLet binds' expr', fvExpr)
+
+rnExpr e@(HsDo do_or_lc stmts _ _ src_loc)
+ = addSrcLoc src_loc $
+ rnStmts do_or_lc stmts `thenM` \ (stmts', fvs) ->
+
+ -- Check the statement list ends in an expression
+ case last stmts' of {
+ ResultStmt _ _ -> returnM () ;
+ _ -> addErr (doStmtListErr do_or_lc e)
+ } `thenM_`
+
+ -- Generate the rebindable syntax for the monad
+ mapAndUnzipM lookupSyntaxName
+ (syntax_names do_or_lc) `thenM` \ (monad_names', monad_fvs) ->
+
+ returnM (HsDo do_or_lc stmts' monad_names' placeHolderType src_loc,
+ fvs `plusFV` implicit_fvs do_or_lc `plusFV` plusFVs monad_fvs)
+ where
+ implicit_fvs PArrComp = mkFVs [replicatePName, mapPName, filterPName, crossPName, zipPName]
+ implicit_fvs ListComp = mkFVs [foldrName, buildName]
+ implicit_fvs DoExpr = emptyFVs
+ implicit_fvs MDoExpr = emptyFVs
+
+ syntax_names DoExpr = monadNames
+ syntax_names MDoExpr = monadNames ++ [mfixName]
+ syntax_names other = []
+
+rnExpr (ExplicitList _ exps)
+ = rnExprs exps `thenM` \ (exps', fvs) ->
+ returnM (ExplicitList placeHolderType exps', fvs `addOneFV` listTyCon_name)
+
+rnExpr (ExplicitPArr _ exps)
+ = rnExprs exps `thenM` \ (exps', fvs) ->
+ returnM (ExplicitPArr placeHolderType exps',
+ fvs `addOneFV` toPName `addOneFV` parrTyCon_name)
+
+rnExpr e@(ExplicitTuple exps boxity)
+ = checkTupSize tup_size `thenM_`
+ rnExprs exps `thenM` \ (exps', fvs) ->
+ returnM (ExplicitTuple exps' boxity, fvs `addOneFV` tycon_name)
+ where
+ tup_size = length exps
+ tycon_name = tupleTyCon_name boxity tup_size
-rnExpr (HsSCC label expr)
- = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
- returnRn (HsSCC label expr', fvs_expr)
+rnExpr (RecordCon con_id rbinds)
+ = lookupOccRn con_id `thenM` \ conname ->
+ rnRbinds "construction" rbinds `thenM` \ (rbinds', fvRbinds) ->
+ returnM (RecordCon conname rbinds', fvRbinds `addOneFV` conname)
-rnExpr (HsCase expr ms src_loc)
- = pushSrcLocRn src_loc $
- rnExpr expr `thenRn` \ (new_expr, e_fvs) ->
- mapAndUnzipRn rnMatch ms `thenRn` \ (new_ms, ms_fvs) ->
- returnRn (HsCase new_expr new_ms src_loc, unionManyUniqSets (e_fvs : ms_fvs))
+rnExpr (RecordUpd expr rbinds)
+ = rnExpr expr `thenM` \ (expr', fvExpr) ->
+ rnRbinds "update" rbinds `thenM` \ (rbinds', fvRbinds) ->
+ returnM (RecordUpd expr' rbinds', fvExpr `plusFV` fvRbinds)
-rnExpr (HsLet binds expr)
- = rnBinds binds `thenRn` \ (binds', fvBinds, new_binders) ->
- extendSS2 new_binders (rnExpr expr) `thenRn` \ (expr',fvExpr) ->
- returnRn (HsLet binds' expr', fvBinds `unionUniqSets` fvExpr)
+rnExpr (ExprWithTySig expr pty)
+ = rnExpr expr `thenM` \ (expr', fvExpr) ->
+ rnHsTypeFVs doc pty `thenM` \ (pty', fvTy) ->
+ returnM (ExprWithTySig expr' pty', fvExpr `plusFV` fvTy)
+ where
+ doc = text "In an expression type signature"
-rnExpr (HsDo stmts src_loc)
- = pushSrcLocRn src_loc $
- rnStmts stmts `thenRn` \ (stmts', fvStmts) ->
- returnRn (HsDo stmts' src_loc, fvStmts)
+rnExpr (HsIf p b1 b2 src_loc)
+ = addSrcLoc src_loc $
+ rnExpr p `thenM` \ (p', fvP) ->
+ rnExpr b1 `thenM` \ (b1', fvB1) ->
+ rnExpr b2 `thenM` \ (b2', fvB2) ->
+ returnM (HsIf p' b1' b2' src_loc, plusFVs [fvP, fvB1, fvB2])
+
+rnExpr (HsType a)
+ = rnHsTypeFVs doc a `thenM` \ (t, fvT) ->
+ returnM (HsType t, fvT)
+ where
+ doc = text "In a type argument"
-rnExpr (ListComp expr quals)
- = rnQuals quals `thenRn` \ ((quals', qual_binders), fvQuals) ->
- extendSS2 qual_binders (rnExpr expr) `thenRn` \ (expr', fvExpr) ->
- returnRn (ListComp expr' quals', fvExpr `unionUniqSets` fvQuals)
+rnExpr (ArithSeqIn seq)
+ = rnArithSeq seq `thenM` \ (new_seq, fvs) ->
+ returnM (ArithSeqIn new_seq, fvs `addOneFV` enumClassName)
-rnExpr (ExplicitList exps)
- = rnExprs exps `thenRn` \ (exps', fvs) ->
- returnRn (ExplicitList exps', fvs)
+rnExpr (PArrSeqIn seq)
+ = rnArithSeq seq `thenM` \ (new_seq, fvs) ->
+ returnM (PArrSeqIn new_seq,
+ fvs `plusFV` mkFVs [enumFromToPName, enumFromThenToPName])
+\end{code}
-rnExpr (ExplicitTuple exps)
- = rnExprs exps `thenRn` \ (exps', fvExps) ->
- returnRn (ExplicitTuple exps', fvExps)
+These three are pattern syntax appearing in expressions.
+Since all the symbols are reservedops we can simply reject them.
+We return a (bogus) EWildPat in each case.
-rnExpr (RecordCon (HsVar con) rbinds)
- = lookupConstr con `thenRn` \ conname ->
- rnRbinds "construction" rbinds `thenRn` \ (rbinds', fvRbinds) ->
- returnRn (RecordCon (HsVar conname) rbinds', fvRbinds)
+\begin{code}
+rnExpr e@EWildPat = addErr (patSynErr e) `thenM_`
+ returnM (EWildPat, emptyFVs)
-rnExpr (RecordUpd expr rbinds)
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
- rnRbinds "update" rbinds `thenRn` \ (rbinds', fvRbinds) ->
- returnRn (RecordUpd expr' rbinds', fvExpr `unionUniqSets` fvRbinds)
+rnExpr e@(EAsPat _ _) = addErr (patSynErr e) `thenM_`
+ returnM (EWildPat, emptyFVs)
-rnExpr (ExprWithTySig expr pty)
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
- rnPolyType nullTyVarNamesEnv pty `thenRn` \ pty' ->
- returnRn (ExprWithTySig expr' pty', fvExpr)
+rnExpr e@(ELazyPat _) = addErr (patSynErr e) `thenM_`
+ returnM (EWildPat, emptyFVs)
+\end{code}
-rnExpr (HsIf p b1 b2 src_loc)
- = pushSrcLocRn src_loc $
- rnExpr p `thenRn` \ (p', fvP) ->
- rnExpr b1 `thenRn` \ (b1', fvB1) ->
- rnExpr b2 `thenRn` \ (b2', fvB2) ->
- returnRn (HsIf p' b1' b2' src_loc, unionManyUniqSets [fvP, fvB1, fvB2])
+%************************************************************************
+%* *
+ Arithmetic sequences
+%* *
+%************************************************************************
-rnExpr (ArithSeqIn seq)
- = rn_seq seq `thenRn` \ (new_seq, fvs) ->
- returnRn (ArithSeqIn new_seq, fvs)
- where
- rn_seq (From expr)
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
- returnRn (From expr', fvExpr)
-
- rn_seq (FromThen expr1 expr2)
- = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
- rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
- returnRn (FromThen expr1' expr2', fvExpr1 `unionUniqSets` fvExpr2)
-
- rn_seq (FromTo expr1 expr2)
- = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
- rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
- returnRn (FromTo expr1' expr2', fvExpr1 `unionUniqSets` fvExpr2)
-
- rn_seq (FromThenTo expr1 expr2 expr3)
- = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
- rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
- rnExpr expr3 `thenRn` \ (expr3', fvExpr3) ->
- returnRn (FromThenTo expr1' expr2' expr3',
- unionManyUniqSets [fvExpr1, fvExpr2, fvExpr3])
+\begin{code}
+rnArithSeq (From expr)
+ = rnExpr expr `thenM` \ (expr', fvExpr) ->
+ returnM (From expr', fvExpr)
+
+rnArithSeq (FromThen expr1 expr2)
+ = rnExpr expr1 `thenM` \ (expr1', fvExpr1) ->
+ rnExpr expr2 `thenM` \ (expr2', fvExpr2) ->
+ returnM (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2)
+
+rnArithSeq (FromTo expr1 expr2)
+ = rnExpr expr1 `thenM` \ (expr1', fvExpr1) ->
+ rnExpr expr2 `thenM` \ (expr2', fvExpr2) ->
+ returnM (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2)
+
+rnArithSeq (FromThenTo expr1 expr2 expr3)
+ = rnExpr expr1 `thenM` \ (expr1', fvExpr1) ->
+ rnExpr expr2 `thenM` \ (expr2', fvExpr2) ->
+ rnExpr expr3 `thenM` \ (expr3', fvExpr3) ->
+ returnM (FromThenTo expr1' expr2' expr3',
+ plusFVs [fvExpr1, fvExpr2, fvExpr3])
\end{code}
+
%************************************************************************
%* *
\subsubsection{@Rbinds@s and @Rpats@s: in record expressions}
\begin{code}
rnRbinds str rbinds
- = mapRn field_dup_err dup_fields `thenRn_`
- mapAndUnzipRn rn_rbind rbinds `thenRn` \ (rbinds', fvRbind_s) ->
- returnRn (rbinds', unionManyUniqSets fvRbind_s)
+ = mappM_ field_dup_err dup_fields `thenM_`
+ mapFvRn rn_rbind rbinds `thenM` \ (rbinds', fvRbind) ->
+ returnM (rbinds', fvRbind)
where
- (_, dup_fields) = removeDups cmp [ f | (f,_,_) <- rbinds ]
-
- field_dup_err dups = getSrcLocRn `thenRn` \ src_loc ->
- addErrRn (dupFieldErr str src_loc dups)
+ (_, dup_fields) = removeDups compare [ f | (f,_) <- rbinds ]
- rn_rbind (field, expr, pun)
- = lookupField field `thenRn` \ fieldname ->
- rnExpr expr `thenRn` \ (expr', fvExpr) ->
- returnRn ((fieldname, expr', pun), fvExpr)
+ field_dup_err dups = addErr (dupFieldErr str dups)
-rnRpats rpats
- = mapRn field_dup_err dup_fields `thenRn_`
- mapRn rn_rpat rpats
- where
- (_, dup_fields) = removeDups cmp [ f | (f,_,_) <- rpats ]
+ rn_rbind (field, expr)
+ = lookupGlobalOccRn field `thenM` \ fieldname ->
+ rnExpr expr `thenM` \ (expr', fvExpr) ->
+ returnM ((fieldname, expr'), fvExpr `addOneFV` fieldname)
+\end{code}
- field_dup_err dups = getSrcLocRn `thenRn` \ src_loc ->
- addErrRn (dupFieldErr "pattern" src_loc dups)
+%************************************************************************
+%* *
+ Template Haskell brackets
+%* *
+%************************************************************************
- rn_rpat (field, pat, pun)
- = lookupField field `thenRn` \ fieldname ->
- rnPat pat `thenRn` \ pat' ->
- returnRn (fieldname, pat', pun)
+\begin{code}
+rnBracket (ExpBr e) = rnExpr e `thenM` \ (e', fvs) ->
+ returnM (ExpBr e', fvs)
+rnBracket (PatBr p) = rnPat p `thenM` \ (p', fvs) ->
+ returnM (PatBr p', fvs)
+rnBracket (TypBr t) = rnHsTypeFVs doc t `thenM` \ (t', fvs) ->
+ returnM (TypBr t', fvs)
+ where
+ doc = ptext SLIT("In a Template-Haskell quoted type")
+rnBracket (DecBr group)
+ = importsFromLocalDecls group `thenM` \ (rdr_env, avails) ->
+ -- Discard avails (not useful here)
+
+ updGblEnv (\gbl -> gbl { tcg_rdr_env = rdr_env `plusGlobalRdrEnv` tcg_rdr_env gbl }) $
+
+ rnSrcDecls group `thenM` \ (tcg_env, group', fvs) ->
+ -- Discard the tcg_env; it contains only extra info about fixity
+
+ returnM (DecBr group', fvs)
\end{code}
%************************************************************************
%* *
-\subsubsection{@Qual@s: in list comprehensions}
+\subsubsection{@Stmt@s: in @do@ expressions}
%* *
%************************************************************************
-Note that although some bound vars may appear in the free var set for
-the first qual, these will eventually be removed by the caller. For
-example, if we have @[p | r <- s, q <- r, p <- q]@, when doing
-@[q <- r, p <- q]@, the free var set for @q <- r@ will
-be @{r}@, and the free var set for the entire Quals will be @{r}@. This
-@r@ will be removed only when we finally return from examining all the
-Quals.
-
\begin{code}
-rnQuals :: [RdrNameQual]
- -> RnM_Fixes s (([RenamedQual], -- renamed qualifiers
- [RnName]), -- qualifiers' binders
- FreeVars) -- free variables
-
-rnQuals [qual] -- must be at least one qual
- = rnQual qual `thenRn` \ ((new_qual, bs), fvs) ->
- returnRn (([new_qual], bs), fvs)
-
-rnQuals (qual: quals)
- = rnQual qual `thenRn` \ ((qual', bs1), fvQuals1) ->
- extendSS2 bs1 (rnQuals quals) `thenRn` \ ((quals', bs2), fvQuals2) ->
- returnRn
- ((qual' : quals', bs1 ++ bs2), -- The ones on the right (bs2) shadow the
- -- ones on the left (bs1)
- fvQuals1 `unionUniqSets` fvQuals2)
-
-rnQual (GeneratorQual pat expr)
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
+rnStmts :: HsStmtContext Name -> [RdrNameStmt] -> RnM ([RenamedStmt], FreeVars)
+
+rnStmts MDoExpr stmts = rnMDoStmts stmts
+rnStmts ctxt stmts = rnNormalStmts ctxt stmts
+
+rnNormalStmts :: HsStmtContext Name -> [RdrNameStmt] -> RnM ([RenamedStmt], FreeVars)
+-- Used for cases *other* than recursive mdo
+-- Implements nested scopes
+
+rnNormalStmts ctxt [] = returnM ([], emptyFVs)
+ -- Happens at the end of the sub-lists of a ParStmts
+
+rnNormalStmts ctxt (ExprStmt expr _ src_loc : stmts)
+ = addSrcLoc src_loc $
+ rnExpr expr `thenM` \ (expr', fv_expr) ->
+ rnNormalStmts ctxt stmts `thenM` \ (stmts', fvs) ->
+ returnM (ExprStmt expr' placeHolderType src_loc : stmts',
+ fv_expr `plusFV` fvs)
+
+rnNormalStmts ctxt [ResultStmt expr src_loc]
+ = addSrcLoc src_loc $
+ rnExpr expr `thenM` \ (expr', fv_expr) ->
+ returnM ([ResultStmt expr' src_loc], fv_expr)
+
+rnNormalStmts ctxt (BindStmt pat expr src_loc : stmts)
+ = addSrcLoc src_loc $
+ rnExpr expr `thenM` \ (expr', fv_expr) ->
+ -- The binders do not scope over the expression
+
+ rnPatsAndThen (StmtCtxt ctxt) [pat] $ \ [pat'] ->
+ rnNormalStmts ctxt stmts `thenM` \ (stmts', fvs) ->
+ returnM (BindStmt pat' expr' src_loc : stmts',
+ fv_expr `plusFV` fvs) -- fv_expr shouldn't really be filtered by
+ -- the rnPatsAndThen, but it does not matter
+
+rnNormalStmts ctxt (LetStmt binds : stmts)
+ = checkErr (ok ctxt binds) (badIpBinds binds) `thenM_`
+ rnBindsAndThen binds ( \ binds' ->
+ rnNormalStmts ctxt stmts `thenM` \ (stmts', fvs) ->
+ returnM (LetStmt binds' : stmts', fvs))
+ where
+ -- We do not allow implicit-parameter bindings in a parallel
+ -- list comprehension. I'm not sure what it might mean.
+ ok (ParStmtCtxt _) (IPBinds _ _) = False
+ ok _ _ = True
+
+rnNormalStmts ctxt (ParStmt stmtss : stmts)
+ = mapFvRn (rnNormalStmts (ParStmtCtxt ctxt)) stmtss `thenM` \ (stmtss', fv_stmtss) ->
let
- binders = collectPatBinders pat
+ bndrss = map collectStmtsBinders stmtss'
in
- getSrcLocRn `thenRn` \ src_loc ->
- newLocalNames "variable in list-comprehension-generator pattern"
- (binders `zip` repeat src_loc) `thenRn` \ new_binders ->
- extendSS new_binders (rnPat pat) `thenRn` \ pat' ->
-
- returnRn ((GeneratorQual pat' expr', new_binders), fvExpr)
+ foldlM checkBndrs [] bndrss `thenM` \ new_binders ->
+ bindLocalNamesFV new_binders $
+ -- Note: binders are returned in scope order, so one may
+ -- shadow the next; e.g. x <- xs; x <- ys
+ rnNormalStmts ctxt stmts `thenM` \ (stmts', fvs) ->
+ returnM (ParStmtOut (bndrss `zip` stmtss') : stmts',
+ fv_stmtss `plusFV` fvs)
+
+ where
+ checkBndrs all_bndrs bndrs
+ = checkErr (null common) (err (head common)) `thenM_`
+ returnM (bndrs ++ all_bndrs)
+ where
+ common = intersectBy eqOcc all_bndrs bndrs
-rnQual (FilterQual expr)
- = rnExpr expr `thenRn` \ (expr', fvs) ->
- returnRn ((FilterQual expr', []), fvs)
+ eqOcc n1 n2 = nameOccName n1 == nameOccName n2
+ err v = ptext SLIT("Duplicate binding in parallel list comprehension for:")
+ <+> quotes (ppr v)
-rnQual (LetQual binds)
- = rnBinds binds `thenRn` \ (binds', binds_fvs, new_binders) ->
- returnRn ((LetQual binds', new_binders), binds_fvs)
+rnNormalStmts ctxt stmts = pprPanic "rnNormalStmts" (ppr stmts)
\end{code}
%************************************************************************
%* *
-\subsubsection{@Stmt@s: in @do@ expressions}
+\subsubsection{Precedence Parsing}
%* *
%************************************************************************
\begin{code}
-rnStmts :: [RdrNameStmt] -> RnM_Fixes s ([RenamedStmt], FreeVars)
-
-rnStmts [stmt@(ExprStmt _ _)] -- last stmt must be ExprStmt
- = rnStmt stmt `thenRn` \ ((stmt',[]), fvStmt) ->
- returnRn ([stmt'], fvStmt)
-
-rnStmts (stmt:stmts)
- = rnStmt stmt `thenRn` \ ((stmt',bs), fvStmt) ->
- extendSS2 bs (rnStmts stmts) `thenRn` \ (stmts', fvStmts) ->
- returnRn (stmt':stmts', fvStmt `unionUniqSets` fvStmts)
-
-
-rnStmt (BindStmt pat expr src_loc)
- = pushSrcLocRn src_loc $
- rnExpr expr `thenRn` \ (expr', fvExpr) ->
+type Defs = NameSet
+type Uses = NameSet -- Same as FreeVars really
+type FwdRefs = NameSet
+type Segment = (Defs,
+ Uses, -- May include defs
+ FwdRefs, -- A subset of uses that are
+ -- (a) used before they are bound in this segment, or
+ -- (b) used here, and bound in subsequent segments
+ [RenamedStmt])
+
+----------------------------------------------------
+rnMDoStmts :: [RdrNameStmt] -> RnM ([RenamedStmt], FreeVars)
+rnMDoStmts stmts
+ = -- Step1: bring all the binders of the mdo into scope
+ bindLocalsRn doc (collectStmtsBinders stmts) $ \ _ ->
+
+ -- 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
+ mappM rn_mdo_stmt stmts `thenM` \ segs ->
let
- binders = collectPatBinders pat
+ -- Step 3: 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
+ -- 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
+ -- 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
+ -- used 'after' the RecStmt
+ stmts_w_fvs = segsToStmts grouped_segs
in
- newLocalNames "variable in do binding"
- (binders `zip` repeat src_loc) `thenRn` \ new_binders ->
- extendSS new_binders (rnPat pat) `thenRn` \ pat' ->
+ returnM stmts_w_fvs
+ where
+ doc = text "In a mdo-expression"
+
+----------------------------------------------------
+rn_mdo_stmt :: RdrNameStmt -> RnM Segment
+ -- Assumes all binders are already in scope
+ -- Turns each stmt into a singleton Stmt
+
+rn_mdo_stmt (ExprStmt expr _ src_loc)
+ = addSrcLoc src_loc (rnExpr expr) `thenM` \ (expr', fvs) ->
+ returnM (emptyNameSet, fvs, emptyNameSet,
+ [ExprStmt expr' placeHolderType src_loc])
+
+rn_mdo_stmt (ResultStmt expr src_loc)
+ = addSrcLoc src_loc (rnExpr expr) `thenM` \ (expr', fvs) ->
+ returnM (emptyNameSet, fvs, emptyNameSet,
+ [ResultStmt expr' src_loc])
+
+rn_mdo_stmt (BindStmt pat expr src_loc)
+ = addSrcLoc src_loc $
+ rnExpr expr `thenM` \ (expr', fv_expr) ->
+ rnPat pat `thenM` \ (pat', fv_pat) ->
+ let
+ bndrs = mkNameSet (collectPatBinders pat')
+ fvs = fv_expr `plusFV` fv_pat
+ in
+ returnM (bndrs, fvs, bndrs `intersectNameSet` fvs,
+ [BindStmt pat' expr' src_loc])
- returnRn ((BindStmt pat' expr' src_loc, new_binders), fvExpr)
+rn_mdo_stmt (LetStmt binds)
+ = rnBinds binds `thenM` \ (binds', fv_binds) ->
+ returnM (mkNameSet (collectHsBinders binds'),
+ fv_binds, emptyNameSet, [LetStmt binds'])
+
+rn_mdo_stmt stmt@(ParStmt _) -- Syntactically illegal in mdo
+ = pprPanic "rn_mdo_stmt" (ppr stmt)
-rnStmt (ExprStmt expr src_loc)
- =
- rnExpr expr `thenRn` \ (expr', fvs) ->
- returnRn ((ExprStmt expr' src_loc, []), fvs)
-rnStmt (LetStmt binds)
- = rnBinds binds `thenRn` \ (binds', binds_fvs, new_binders) ->
- returnRn ((LetStmt binds', new_binders), binds_fvs)
+addFwdRefs :: [Segment] -> [Segment]
+-- So far the segments only have forward refs *within* the Stmt
+-- (which happens for bind: x <- ...x...)
+-- This function adds the cross-seg fwd ref info
+addFwdRefs pairs
+ = fst (foldr mk_seg ([], emptyNameSet) pairs)
+ where
+ mk_seg (defs, uses, fwds, stmts) (segs, seg_defs)
+ = (new_seg : segs, all_defs)
+ where
+ new_seg = (defs, uses, new_fwds, stmts)
+ all_defs = seg_defs `unionNameSets` defs
+ new_fwds = fwds `unionNameSets` (uses `intersectNameSet` seg_defs)
+ -- Add the downstream fwd refs here
+
+----------------------------------------------------
+-- Glomming the singleton segments of an mdo into
+-- minimal recursive groups.
+--
+-- At first I thought this was just strongly connected components, but
+-- there's an important constraint: the order of the stmts must not change.
+--
+-- Consider
+-- mdo { x <- ...y...
+-- p <- z
+-- y <- ...x...
+-- q <- x
+-- z <- y
+-- r <- x }
+--
+-- Here, the first stmt mention 'y', which is bound in the third.
+-- But that means that the innocent second stmt (p <- z) gets caught
+-- up in the recursion. And that in turn means that the binding for
+-- 'z' has to be included... and so on.
+--
+-- Start at the tail { r <- x }
+-- Now add the next one { z <- y ; r <- x }
+-- Now add one more { q <- x ; z <- y ; r <- x }
+-- Now one more... but this time we have to group a bunch into rec
+-- { rec { y <- ...x... ; q <- x ; z <- y } ; r <- x }
+-- Now one more, which we can add on without a rec
+-- { p <- z ;
+-- rec { y <- ...x... ; q <- x ; z <- y } ;
+-- r <- x }
+-- Finally we add the last one; since it mentions y we have to
+-- glom it togeher with the first two groups
+-- { rec { x <- ...y...; p <- z ; y <- ...x... ;
+-- q <- x ; z <- y } ;
+-- r <- x }
+
+glomSegments :: [Segment] -> [Segment]
+
+glomSegments [seg] = [seg]
+glomSegments ((defs,uses,fwds,stmts) : segs)
+ -- Actually stmts will always be a singleton
+ = (seg_defs, seg_uses, seg_fwds, seg_stmts) : others
+ where
+ segs' = glomSegments segs
+ (extras, others) = grab uses segs'
+ (ds, us, fs, ss) = unzip4 extras
+
+ seg_defs = plusFVs ds `plusFV` defs
+ seg_uses = plusFVs us `plusFV` uses
+ seg_fwds = plusFVs fs `plusFV` fwds
+ seg_stmts = stmts ++ concat ss
+
+ grab :: NameSet -- The client
+ -> [Segment]
+ -> ([Segment], -- Needed by the 'client'
+ [Segment]) -- Not needed by the client
+ -- The result is simply a split of the input
+ grab uses dus
+ = (reverse yeses, reverse noes)
+ where
+ (noes, yeses) = span not_needed (reverse dus)
+ not_needed (defs,_,_,_) = not (intersectsNameSet defs uses)
+
+
+----------------------------------------------------
+segsToStmts :: [Segment] -> ([RenamedStmt], FreeVars)
+
+segsToStmts [] = ([], emptyFVs)
+segsToStmts ((defs, uses, fwds, ss) : segs)
+ = (new_stmt : later_stmts, later_uses `plusFV` uses)
+ where
+ (later_stmts, later_uses) = segsToStmts segs
+ new_stmt | non_rec = head ss
+ | otherwise = RecStmt rec_names ss []
+ where
+ non_rec = isSingleton ss && isEmptyNameSet fwds
+ rec_names = nameSetToList (fwds `plusFV` (defs `intersectNameSet` later_uses))
+ -- The names for the fixpoint are
+ -- (a) the ones needed after the RecStmt
+ -- (b) the forward refs within the fixpoint
\end{code}
%************************************************************************
%* *
%************************************************************************
-\begin{code}
-precParseExpr :: RenamedHsExpr -> RnM_Fixes s RenamedHsExpr
-precParsePat :: RenamedPat -> RnM_Fixes s RenamedPat
-
-precParseExpr exp@(OpApp (NegApp e1 n) (HsVar op) e2)
- = lookupFixity op `thenRn` \ (op_fix, op_prec) ->
- if 6 < op_prec then
- -- negate precedence 6 wired in
- -- (-x)*y ==> -(x*y)
- precParseExpr (OpApp e1 (HsVar op) e2) `thenRn` \ op_app ->
- returnRn (NegApp op_app n)
- else
- returnRn exp
-
-precParseExpr exp@(OpApp (OpApp e11 (HsVar op1) e12) (HsVar op) e2)
- = lookupFixity op `thenRn` \ (op_fix, op_prec) ->
- lookupFixity op1 `thenRn` \ (op1_fix, op1_prec) ->
- -- pprTrace "precParse:" (ppCat [ppr PprDebug op, ppInt op_prec, ppr PprDebug op1, ppInt op1_prec]) $
- case (op1_prec `cmp` op_prec) of
- LT_ -> rearrange
- EQ_ -> case (op1_fix, op_fix) of
- (INFIXR, INFIXR) -> rearrange
- (INFIXL, INFIXL) -> returnRn exp
- _ -> getSrcLocRn `thenRn` \ src_loc ->
- failButContinueRn exp
- (precParseErr (op1,op1_fix,op1_prec) (op,op_fix,op_prec) src_loc)
- GT__ -> returnRn exp
- where
- rearrange = precParseExpr (OpApp e12 (HsVar op) e2) `thenRn` \ e2' ->
- returnRn (OpApp e11 (HsVar op1) e2')
-
-precParseExpr exp = returnRn exp
+@mkOpAppRn@ deals with operator fixities. The argument expressions
+are assumed to be already correctly arranged. It needs the fixities
+recorded in the OpApp nodes, because fixity info applies to the things
+the programmer actually wrote, so you can't find it out from the Name.
+Furthermore, the second argument is guaranteed not to be another
+operator application. Why? Because the parser parses all
+operator appications left-associatively, EXCEPT negation, which
+we need to handle specially.
-precParsePat pat@(ConOpPatIn (NegPatIn e1) op e2)
- = lookupFixity op `thenRn` \ (op_fix, op_prec) ->
- if 6 < op_prec then
- -- negate precedence 6 wired in
- getSrcLocRn `thenRn` \ src_loc ->
- failButContinueRn pat (precParseNegPatErr (op,op_fix,op_prec) src_loc)
- else
- returnRn pat
-
-precParsePat pat@(ConOpPatIn (ConOpPatIn p11 op1 p12) op p2)
- = lookupFixity op `thenRn` \ (op_fix, op_prec) ->
- lookupFixity op1 `thenRn` \ (op1_fix, op1_prec) ->
- case (op1_prec `cmp` op_prec) of
- LT_ -> rearrange
- EQ_ -> case (op1_fix, op_fix) of
- (INFIXR, INFIXR) -> rearrange
- (INFIXL, INFIXL) -> returnRn pat
- _ -> getSrcLocRn `thenRn` \ src_loc ->
- failButContinueRn pat
- (precParseErr (op1,op1_fix,op1_prec) (op,op_fix,op_prec) src_loc)
- GT__ -> returnRn pat
+\begin{code}
+mkOpAppRn :: RenamedHsExpr -- Left operand; already rearranged
+ -> RenamedHsExpr -> Fixity -- Operator and fixity
+ -> RenamedHsExpr -- Right operand (not an OpApp, but might
+ -- be a NegApp)
+ -> RnM RenamedHsExpr
+
+---------------------------
+-- (e11 `op1` e12) `op2` e2
+mkOpAppRn e1@(OpApp e11 op1 fix1 e12) op2 fix2 e2
+ | nofix_error
+ = addErr (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenM_`
+ returnM (OpApp e1 op2 fix2 e2)
+
+ | associate_right
+ = mkOpAppRn e12 op2 fix2 e2 `thenM` \ new_e ->
+ returnM (OpApp e11 op1 fix1 new_e)
where
- rearrange = precParsePat (ConOpPatIn p12 op p2) `thenRn` \ p2' ->
- returnRn (ConOpPatIn p11 op1 p2')
-
-precParsePat pat = returnRn pat
-
-
-data INFIX = INFIXL | INFIXR | INFIXN deriving Eq
+ (nofix_error, associate_right) = compareFixity fix1 fix2
+
+---------------------------
+-- (- neg_arg) `op` e2
+mkOpAppRn e1@(NegApp neg_arg neg_name) op2 fix2 e2
+ | nofix_error
+ = addErr (precParseErr (pp_prefix_minus,negateFixity) (ppr_op op2,fix2)) `thenM_`
+ returnM (OpApp e1 op2 fix2 e2)
+
+ | associate_right
+ = mkOpAppRn neg_arg op2 fix2 e2 `thenM` \ new_e ->
+ returnM (NegApp new_e neg_name)
+ where
+ (nofix_error, associate_right) = compareFixity negateFixity fix2
+
+---------------------------
+-- e1 `op` - neg_arg
+mkOpAppRn e1 op1 fix1 e2@(NegApp neg_arg _) -- NegApp can occur on the right
+ | not associate_right -- We *want* right association
+ = addErr (precParseErr (ppr_op op1, fix1) (pp_prefix_minus, negateFixity)) `thenM_`
+ returnM (OpApp e1 op1 fix1 e2)
+ where
+ (_, associate_right) = compareFixity fix1 negateFixity
+
+---------------------------
+-- Default case
+mkOpAppRn e1 op fix e2 -- Default case, no rearrangment
+ = ASSERT2( right_op_ok fix e2,
+ ppr e1 $$ text "---" $$ ppr op $$ text "---" $$ ppr fix $$ text "---" $$ ppr e2
+ )
+ returnM (OpApp e1 op fix e2)
+
+-- Parser left-associates everything, but
+-- derived instances may have correctly-associated things to
+-- in the right operarand. So we just check that the right operand is OK
+right_op_ok fix1 (OpApp _ _ fix2 _)
+ = not error_please && associate_right
+ where
+ (error_please, associate_right) = compareFixity fix1 fix2
+right_op_ok fix1 other
+ = True
-lookupFixity :: RnName -> RnM_Fixes s (INFIX, Int)
-lookupFixity op
- = getExtraRn `thenRn` \ fixity_fm ->
- -- pprTrace "lookupFixity:" (ppAboves [ppCat [pprUnique u, ppr PprDebug i_f] | (u,i_f) <- ufmToList fixity_fm]) $
- case lookupUFM fixity_fm op of
- Nothing -> returnRn (INFIXL, 9)
- Just (InfixL _ n) -> returnRn (INFIXL, n)
- Just (InfixR _ n) -> returnRn (INFIXR, n)
- Just (InfixN _ n) -> returnRn (INFIXN, n)
+-- Parser initially makes negation bind more tightly than any other operator
+mkNegAppRn neg_arg neg_name
+ =
+#ifdef DEBUG
+ getModeRn `thenM` \ mode ->
+ ASSERT( not_op_app mode neg_arg )
+#endif
+ returnM (NegApp neg_arg neg_name)
+
+not_op_app SourceMode (OpApp _ _ _ _) = False
+not_op_app mode other = True
\end{code}
\begin{code}
-checkPrecMatch :: Bool -> RnName -> RenamedMatch -> RnM_Fixes s ()
+checkPrecMatch :: Bool -> Name -> RenamedMatch -> RnM ()
checkPrecMatch False fn match
- = returnRn ()
-checkPrecMatch True op (PatMatch p1 (PatMatch p2 (GRHSMatch _)))
- = checkPrec op p1 False `thenRn_`
- checkPrec op p2 True
-checkPrecMatch True op _
- = panic "checkPrecMatch"
-
-checkPrec op (ConOpPatIn _ op1 _) right
- = lookupFixity op `thenRn` \ (op_fix, op_prec) ->
- lookupFixity op1 `thenRn` \ (op1_fix, op1_prec) ->
- getSrcLocRn `thenRn` \ src_loc ->
+ = returnM ()
+
+checkPrecMatch True op (Match (p1:p2:_) _ _)
+ -- True indicates an infix lhs
+ = getModeRn `thenM` \ mode ->
+ -- See comments with rnExpr (OpApp ...)
+ if isInterfaceMode mode
+ then returnM ()
+ else checkPrec op p1 False `thenM_`
+ checkPrec op p2 True
+
+checkPrecMatch True op _ = panic "checkPrecMatch"
+
+checkPrec op (ConPatIn op1 (InfixCon _ _)) right
+ = lookupFixityRn op `thenM` \ op_fix@(Fixity op_prec op_dir) ->
+ lookupFixityRn op1 `thenM` \ op1_fix@(Fixity op1_prec op1_dir) ->
let
inf_ok = op1_prec > op_prec ||
(op1_prec == op_prec &&
- (op1_fix == INFIXR && op_fix == INFIXR && right ||
- op1_fix == INFIXL && op_fix == INFIXL && not right))
+ (op1_dir == InfixR && op_dir == InfixR && right ||
+ op1_dir == InfixL && op_dir == InfixL && not right))
- info = (op,op_fix,op_prec)
- info1 = (op1,op1_fix,op1_prec)
+ info = (ppr_op op, op_fix)
+ info1 = (ppr_op op1, op1_fix)
(infol, infor) = if right then (info, info1) else (info1, info)
in
- addErrIfRn (not inf_ok) (precParseErr infol infor src_loc)
-
-checkPrec op (NegPatIn _) right
- = lookupFixity op `thenRn` \ (op_fix, op_prec) ->
- getSrcLocRn `thenRn` \ src_loc ->
- addErrIfRn (6 < op_prec) (precParseNegPatErr (op,op_fix,op_prec) src_loc)
+ checkErr inf_ok (precParseErr infol infor)
checkPrec op pat right
- = returnRn ()
+ = returnM ()
+
+-- Check precedence of (arg op) or (op arg) respectively
+-- If arg is itself an operator application, then either
+-- (a) its precedence must be higher than that of op
+-- (b) its precedency & associativity must be the same as that of op
+checkSectionPrec direction section op arg
+ = case arg of
+ OpApp _ op fix _ -> go_for_it (ppr_op op) fix
+ NegApp _ _ -> go_for_it pp_prefix_minus negateFixity
+ other -> returnM ()
+ where
+ HsVar op_name = op
+ go_for_it pp_arg_op arg_fix@(Fixity arg_prec assoc)
+ = lookupFixityRn op_name `thenM` \ op_fix@(Fixity op_prec _) ->
+ checkErr (op_prec < arg_prec
+ || op_prec == arg_prec && direction == assoc)
+ (sectionPrecErr (ppr_op op_name, op_fix)
+ (pp_arg_op, arg_fix) section)
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsubsection{Assertion utils}
+%* *
+%************************************************************************
+
+\begin{code}
+mkAssertErrorExpr :: RnM (RenamedHsExpr, FreeVars)
+-- Return an expression for (assertError "Foo.hs:27")
+mkAssertErrorExpr
+ = getSrcLocM `thenM` \ sloc ->
+ let
+ expr = HsApp (HsVar assertErrorName) (HsLit msg)
+ msg = HsStringPrim (mkFastString (stringToUtf8 (showSDoc (ppr sloc))))
+ in
+ returnM (expr, unitFV assertErrorName)
\end{code}
+%************************************************************************
+%* *
+\subsubsection{Errors}
+%* *
+%************************************************************************
+
\begin{code}
-dupFieldErr str src_loc (dup:rest)
- = addShortErrLocLine src_loc (\ sty ->
- ppBesides [ppStr "duplicate field name `", ppr sty dup, ppStr "' in record ", ppStr str])
-
-negPatErr pat src_loc
- = addShortErrLocLine src_loc (\ sty ->
- ppSep [ppStr "prefix `-' not applied to literal in pattern", ppr sty pat])
-
-precParseNegPatErr op src_loc
- = addErrLoc src_loc "precedence parsing error" (\ sty ->
- ppBesides [ppStr "prefix `-' has lower precedence than ", pp_op sty op, ppStr " in pattern"])
-
-precParseErr op1 op2 src_loc
- = addErrLoc src_loc "precedence parsing error" (\ sty ->
- ppBesides [ppStr "cannot mix ", pp_op sty op1, ppStr " and ", pp_op sty op2,
- ppStr " in the same infix expression"])
-
-pp_op sty (op, fix, prec) = ppBesides [pprSym sty op, ppLparen, pp_fix fix, ppSP, ppInt prec, ppRparen]
-pp_fix INFIXL = ppStr "infixl"
-pp_fix INFIXR = ppStr "infixr"
-pp_fix INFIXN = ppStr "infix"
+ppr_op op = quotes (ppr op) -- Here, op can be a Name or a (Var n), where n is a Name
+pp_prefix_minus = ptext SLIT("prefix `-'")
+
+nonStdGuardErr guard
+ = hang (ptext
+ SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)")
+ ) 4 (ppr guard)
+
+patSynErr e
+ = sep [ptext SLIT("Pattern syntax in expression context:"),
+ nest 4 (ppr e)]
+
+doStmtListErr do_or_lc e
+ = sep [quotes (text binder_name) <+> ptext SLIT("statements must end in expression:"),
+ nest 4 (ppr e)]
+ where
+ binder_name = case do_or_lc of
+ MDoExpr -> "mdo"
+ other -> "do"
+
+#ifdef GHCI
+checkTH e what = returnM () -- OK
+#else
+checkTH e what -- Raise an error in a stage-1 compiler
+ = addErr (vcat [ptext SLIT("Template Haskell") <+> text what <+>
+ ptext SLIT("illegal in a stage-1 compiler"),
+ nest 2 (ppr e)])
+#endif
+
+badIpBinds binds
+ = hang (ptext SLIT("Implicit-parameter bindings illegal in a parallel list comprehension:")) 4
+ (ppr binds)
\end{code}
projects / ghc-hetmet.git / blobdiff