TcMatches: Typecheck some @Matches@
\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 TcMatches ( tcMatchesFun, tcGRHSsPat, tcMatchesCase, tcMatchLambda,
matchCtxt, TcMatchCtxt(..),
tcStmts, tcDoStmts, tcBody,
same number of arguments before using @tcMatches@ to do the work.
\begin{code}
-tcMatchesFun :: Name
+tcMatchesFun :: Name -> Bool
-> MatchGroup Name
-> BoxyRhoType -- Expected type of function
-> TcM (HsWrapper, MatchGroup TcId) -- Returns type of body
-tcMatchesFun fun_name matches exp_ty
+tcMatchesFun fun_name inf matches exp_ty
= do { -- Check that they all have the same no of arguments
-- Location is in the monad, set the caller so that
-- any inter-equation error messages get some vaguely
doc = ptext SLIT("The equation(s) for") <+> quotes (ppr fun_name)
<+> ptext SLIT("have") <+> speakNOf n_pats (ptext SLIT("argument"))
n_pats = matchGroupArity matches
- match_ctxt = MC { mc_what = FunRhs fun_name, mc_body = tcBody }
+ match_ctxt = MC { mc_what = FunRhs fun_name inf, mc_body = tcBody }
\end{code}
@tcMatchesCase@ doesn't do the argument-count check because the
where
n_pats = matchGroupArity match
doc = sep [ ptext SLIT("The lambda expression")
- <+> quotes (pprSetDepth 1 $ pprMatches LambdaExpr match),
+ <+> quotes (pprSetDepth 1 $ pprMatches (LambdaExpr :: HsMatchContext Name) match),
-- The pprSetDepth makes the abstraction print briefly
ptext SLIT("has") <+> speakNOf n_pats (ptext SLIT("argument"))]
match_ctxt = MC { mc_what = LambdaExpr,
= wrapLocM (tc_match ctxt pat_tys rhs_ty) match
where
tc_match ctxt pat_tys rhs_ty match@(Match pats maybe_rhs_sig grhss)
- = addErrCtxt (matchCtxt (mc_what ctxt) match) $
+ = add_match_ctxt match $
do { (pats', grhss') <- tcLamPats pats pat_tys rhs_ty $
tc_grhss ctxt maybe_rhs_sig grhss
; return (Match pats' Nothing grhss') }
<+> ppr res_sig)
; tcGRHSs ctxt grhss (co, rhs_ty) }
+ -- 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
+
-------------
tcGRHSs :: TcMatchCtxt -> GRHSs Name -> (Refinement, BoxyRhoType)
-> TcM (GRHSs TcId)
-> BoxyRhoType
-> TcM (HsExpr TcId) -- Returns a HsDo
tcDoStmts ListComp stmts body res_ty
- = do { elt_ty <- boxySplitListTy res_ty
+ = do { (elt_ty, coi) <- boxySplitListTy res_ty
; (stmts', body') <- tcStmts ListComp (tcLcStmt listTyCon) stmts
(emptyRefinement,elt_ty) $
tcBody body
- ; return (HsDo ListComp stmts' body' (mkListTy elt_ty)) }
+ ; return $ mkHsWrapCoI coi
+ (HsDo ListComp stmts' body' (mkListTy elt_ty)) }
tcDoStmts PArrComp stmts body res_ty
- = do { [elt_ty] <- boxySplitTyConApp parrTyCon res_ty
+ = do { (elt_ty, coi) <- boxySplitPArrTy res_ty
; (stmts', body') <- tcStmts PArrComp (tcLcStmt parrTyCon) stmts
(emptyRefinement, elt_ty) $
tcBody body
- ; return (HsDo PArrComp stmts' body' (mkPArrTy elt_ty)) }
+ ; return $ mkHsWrapCoI coi
+ (HsDo PArrComp stmts' body' (mkPArrTy elt_ty)) }
tcDoStmts DoExpr stmts body res_ty
- = do { (m_ty, elt_ty) <- boxySplitAppTy res_ty
+ = do { ((m_ty, elt_ty), coi) <- boxySplitAppTy res_ty
; let res_ty' = mkAppTy m_ty elt_ty -- The boxySplit consumes res_ty
; (stmts', body') <- tcStmts DoExpr (tcDoStmt m_ty) stmts
(emptyRefinement, res_ty') $
tcBody body
- ; return (HsDo DoExpr stmts' body' res_ty') }
+ ; return $ mkHsWrapCoI coi (HsDo DoExpr stmts' body' res_ty') }
tcDoStmts ctxt@(MDoExpr _) stmts body res_ty
- = do { (m_ty, elt_ty) <- boxySplitAppTy res_ty
+ = do { ((m_ty, elt_ty), coi) <- boxySplitAppTy res_ty
; let res_ty' = mkAppTy m_ty elt_ty -- The boxySplit consumes res_ty
tc_rhs rhs = withBox liftedTypeKind $ \ pat_ty ->
tcMonoExpr rhs (mkAppTy m_ty pat_ty)
; let names = [mfixName, bindMName, thenMName, returnMName, failMName]
; insts <- mapM (newMethodFromName DoOrigin m_ty) names
- ; return (HsDo (MDoExpr (names `zip` insts)) stmts' body' res_ty') }
+ ; return $
+ mkHsWrapCoI coi
+ (HsDo (MDoExpr (names `zip` insts)) stmts' body' res_ty') }
tcDoStmts ctxt stmts body res_ty = pprPanic "tcDoStmts" (pprStmtContext ctxt)