matchContextErrString (StmtCtxt ListComp) = "list comprehension"
matchContextErrString (StmtCtxt PArrComp) = "array comprehension"
\end{code}
+
+\begin{code}
+pprMatchInCtxt :: (OutputableBndr idL, OutputableBndr idR)
+ => HsMatchContext idL -> Match idR -> SDoc
+pprMatchInCtxt ctxt match = hang (ptext (sLit "In") <+> pprMatchContext ctxt <> colon)
+ 4 (pprMatch ctxt match)
+
+pprStmtInCtxt :: (OutputableBndr idL, OutputableBndr idR)
+ => HsStmtContext idL -> StmtLR idL idR -> SDoc
+pprStmtInCtxt ctxt stmt = hang (ptext (sLit "In a stmt of") <+> pprStmtContext ctxt <> colon)
+ 4 (ppr stmt)
+\end{code}
import RdrHsSyn
import RnHsSyn
import TcRnMonad
-import RnTypes ( rnHsSigType, rnLHsType, rnHsTypeFVs,checkPrecMatch)
+import RnTypes ( rnHsSigType, rnLHsType, checkPrecMatch)
import RnPat (rnPatsAndThen_LocalRightwards, rnBindPat,
- NameMaker, localRecNameMaker, topRecNameMaker, applyNameMaker,
- patSigErr)
+ NameMaker, localRecNameMaker, topRecNameMaker, applyNameMaker
+ )
import RnEnv
import PrelNames ( mkUnboundName )
rnMatch ctxt = wrapLocFstM (rnMatch' ctxt)
rnMatch' :: HsMatchContext Name -> Match RdrName -> RnM (Match Name, FreeVars)
-rnMatch' ctxt (Match pats maybe_rhs_sig grhss)
- =
- -- Deal with the rhs type signature
- bindPatSigTyVarsFV rhs_sig_tys $ do
- opt_PatternSignatures <- doptM Opt_PatternSignatures
- (maybe_rhs_sig', ty_fvs) <-
- case maybe_rhs_sig of
- Nothing -> return (Nothing, emptyFVs)
- Just ty | opt_PatternSignatures -> do (ty', ty_fvs) <- rnHsTypeFVs doc_sig ty
- return (Just ty', ty_fvs)
- | otherwise -> do addLocErr ty patSigErr
- return (Nothing, emptyFVs)
-
- -- Now the main event
- -- note that there are no local ficity decls for matches
- rnPatsAndThen_LocalRightwards ctxt pats $ \ pats' -> do
- (grhss', grhss_fvs) <- rnGRHSs ctxt grhss
-
- return (Match pats' maybe_rhs_sig' grhss', grhss_fvs `plusFV` ty_fvs)
+rnMatch' ctxt match@(Match pats maybe_rhs_sig grhss)
+ = do { -- Result type signatures are no longer supported
+ case maybe_rhs_sig of
+ Nothing -> return ()
+ Just ty -> addLocErr ty (resSigErr ctxt match)
+
+
+ -- Now the main event
+ -- note that there are no local ficity decls for matches
+ ; rnPatsAndThen_LocalRightwards ctxt pats $ \ pats' -> do
+ { (grhss', grhss_fvs) <- rnGRHSs ctxt grhss
+
+ ; return (Match pats' Nothing grhss', grhss_fvs) }}
-- The bindPatSigTyVarsFV and rnPatsAndThen will remove the bound FVs
where
- rhs_sig_tys = case maybe_rhs_sig of
- Nothing -> []
- Just ty -> [ty]
- doc_sig = text "In a result type-signature"
+
+resSigErr :: HsMatchContext Name -> Match RdrName -> HsType RdrName -> SDoc
+resSigErr ctxt match ty
+ = vcat [ ptext (sLit "Illegal result type signature") <+> quotes (ppr ty)
+ , nest 2 $ ptext (sLit "Result signatures are no longer supported in pattern matches")
+ , pprMatchInCtxt ctxt match ]
\end{code}
tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats _maybe_rhs_sig grhss))] _))
(cmd_stk, res_ty)
- = addErrCtxt (matchCtxt match_ctxt match) $
+ = addErrCtxt (pprMatchInCtxt match_ctxt match) $
do { -- Check the cmd stack is big enough
; checkTc (lengthAtLeast cmd_stk n_pats)
\begin{code}
module TcMatches ( tcMatchesFun, tcGRHSsPat, tcMatchesCase, tcMatchLambda,
- matchCtxt, TcMatchCtxt(..),
+ TcMatchCtxt(..),
tcStmts, tcDoStmts, tcBody,
tcDoStmt, tcMDoStmt, tcGuardStmt
) where
= tcGRHSs ctxt grhss rhs_ty -- No result signature
-- Result type sigs are no longer supported
- tc_grhss ctxt (Just res_sig) grhss rhs_ty
- = do { addErr (ptext (sLit "Ignoring (deprecated) result type signature")
- <+> ppr res_sig)
- ; tcGRHSs ctxt grhss rhs_ty }
+ tc_grhss _ (Just {}) _ _
+ = panic "tc_ghrss" -- Rejected by renamer
-- For (\x -> e), tcExpr has already said "In the expresssion \x->e"
-- so we don't want to add "In the lambda abstraction \x->e"
add_match_ctxt match thing_inside
= case mc_what ctxt of
LambdaExpr -> thing_inside
- m_ctxt -> addErrCtxt (matchCtxt m_ctxt match) thing_inside
+ m_ctxt -> addErrCtxt (pprMatchInCtxt m_ctxt match) thing_inside
-------------
tcGRHSs :: TcMatchCtxt -> GRHSs Name -> BoxyRhoType
tcStmts ctxt stmt_chk (L loc stmt : stmts) res_ty thing_inside
= do { (stmt', (stmts', thing)) <-
setSrcSpan loc $
- addErrCtxt (stmtCtxt ctxt stmt) $
+ addErrCtxt (pprStmtInCtxt ctxt stmt) $
stmt_chk ctxt stmt res_ty $ \ res_ty' ->
popErrCtxt $
tcStmts ctxt stmt_chk stmts res_ty' $
checkArgs _ _ = panic "TcPat.checkArgs" -- Matches always non-empty
\end{code}
-\begin{code}
-matchCtxt :: HsMatchContext Name -> Match Name -> SDoc
-matchCtxt ctxt match = hang (ptext (sLit "In") <+> pprMatchContext ctxt <> colon)
- 4 (pprMatch ctxt match)
-
-stmtCtxt :: HsStmtContext Name -> StmtLR Name Name -> SDoc
-stmtCtxt ctxt stmt = hang (ptext (sLit "In a stmt of") <+> pprStmtContext ctxt <> colon)
- 4 (ppr stmt)
-\end{code}