import {-# SOURCE #-} DsExpr( dsExpr )
import CmdLineOpts ( DynFlag(..), dopt )
import HsSyn
-import TcHsSyn ( TypecheckedPat, TypecheckedMatch, TypecheckedMatchContext, outPatType )
+import TcHsSyn ( hsPatType )
import Check ( check, ExhaustivePat )
import CoreSyn
import CoreUtils ( bindNonRec )
import MatchLit ( matchLiterals )
import PrelInfo ( pAT_ERROR_ID )
import TcType ( mkTyVarTys, Type, tcTyConAppArgs, tcEqType )
-import TysWiredIn ( nilDataCon, consDataCon, mkTupleTy, mkListTy,
+import TysWiredIn ( consDataCon, mkTupleTy, mkListTy,
tupleCon, parrFakeCon, mkPArrTy )
import BasicTypes ( Boxity(..) )
import UniqSet
-import ErrUtils ( addWarnLocHdrLine, dontAddErrLoc )
+import SrcLoc ( noSrcSpan, noLoc, unLoc, Located(..) )
import Util ( lengthExceeds, isSingleton, notNull )
+import Name ( Name )
import Outputable
\end{code}
| otherwise = empty
pp_context NoMatchContext msg rest_of_msg_fun
- = dontAddErrLoc (ptext SLIT("Some match(es)") <+> hang msg 8 (rest_of_msg_fun id))
+ = (noSrcSpan, ptext SLIT("Some match(es)") <+> hang msg 8 (rest_of_msg_fun id))
pp_context (DsMatchContext kind pats loc) msg rest_of_msg_fun
- = addWarnLocHdrLine loc
- (ptext SLIT("Pattern match(es)") <+> msg)
- (sep [ppr_match <> char ':', nest 4 (rest_of_msg_fun pref)])
+ = (loc, vcat [ptext SLIT("Pattern match(es)") <+> msg,
+ sep [ptext SLIT("In") <+> ppr_match <> char ':', nest 4 (rest_of_msg_fun pref)]])
where
(ppr_match, pref)
= case kind of
- FunRhs fun -> (pprMatchContext kind, \ pp -> ppr fun <+> pp)
- other -> (pprMatchContext kind <+> ppr_pats pats, \ pp -> pp)
+ FunRhs fun -> (pprMatchContext kind, \ pp -> ppr fun <+> pp)
+ other -> (pprMatchContext kind, \ pp -> pp)
ppr_pats pats = sep (map ppr pats)
\begin{code}
match vars@(v:vs) eqns_info
- = mapDs (tidyEqnInfo v) eqns_info `thenDs` \ tidy_eqns_info ->
+ = mappM (tidyEqnInfo v) eqns_info `thenDs` \ tidy_eqns_info ->
let
tidy_eqns_blks = unmix_eqns tidy_eqns_info
in
- mapDs (matchEqnBlock vars) tidy_eqns_blks `thenDs` \ match_results ->
+ mappM (matchEqnBlock vars) tidy_eqns_blks `thenDs` \ match_results ->
returnDs (foldr1 combineMatchResults match_results)
where
unmix_eqns [] = []
Float, Double, at least) are converted to unboxed form; e.g.,
\tr{(NPat (HsInt i) _ _)} is converted to:
\begin{verbatim}
-(ConPat I# _ _ [LitPat (HsIntPrim i) _])
+(ConPat I# _ _ [LitPat (HsIntPrim i)])
\end{verbatim}
\end{description}
= tidy1 v pat match_result `thenDs` \ (pat', match_result') ->
returnDs (EqnInfo n ctx (pat' : pats) match_result')
+
+tidy1 :: Id -- The Id being scrutinised
+ -> Pat Id -- The pattern against which it is to be matched
+ -> MatchResult -- Current thing do do after matching
+ -> DsM (Pat Id, -- Equivalent pattern
+ MatchResult) -- Augmented thing to do afterwards
+ -- The augmentation usually takes the form
+ -- of new bindings to be added to the front
+
-------------------------------------------------------
-- (pat', mr') = tidy1 v pat mr
-- tidies the *outer level only* of pat, giving pat'
-- NPlusKPat
--
-
-tidy1 :: Id -- The Id being scrutinised
- -> TypecheckedPat -- The pattern against which it is to be matched
- -> MatchResult -- Current thing do do after matching
- -> DsM (TypecheckedPat, -- Equivalent pattern
- MatchResult) -- Augmented thing to do afterwards
- -- The augmentation usually takes the form
- -- of new bindings to be added to the front
+tidy1 v (ParPat pat) match_result
+ = tidy1 v (unLoc pat) match_result
-- case v of { x -> mr[] }
-- = case v of { _ -> let x=v in mr[] }
-- case v of { x@p -> mr[] }
-- = case v of { p -> let x=v in mr[] }
-tidy1 v (AsPat var pat) match_result
- = tidy1 v pat match_result'
+tidy1 v (AsPat (L _ var) pat) match_result
+ = tidy1 v (unLoc pat) match_result'
where
match_result' | v == var = match_result
| otherwise = adjustMatchResult (bindNonRec var (Var v)) match_result
-- re-express <con-something> as (ConPat ...) [directly]
-tidy1 v (RecPat data_con pat_ty ex_tvs dicts rpats) match_result
- | null rpats
- = -- Special case for C {}, which can be used for
- -- a constructor that isn't declared to have
- -- fields at all
- returnDs (ConPat data_con pat_ty ex_tvs dicts (map WildPat con_arg_tys'), match_result)
-
- | otherwise
- = returnDs (ConPat data_con pat_ty ex_tvs dicts pats, match_result)
+tidy1 v (ConPatOut con ps pat_ty ex_tvs dicts) match_result
+ = returnDs (ConPatOut con tidy_ps pat_ty ex_tvs dicts, match_result)
where
- pats = map mk_pat tagged_arg_tys
-
- -- Boring stuff to find the arg-tys of the constructor
- inst_tys = tcTyConAppArgs pat_ty -- Newtypes must be opaque
- con_arg_tys' = dataConInstOrigArgTys data_con (inst_tys ++ mkTyVarTys ex_tvs)
- tagged_arg_tys = con_arg_tys' `zip` (dataConFieldLabels data_con)
+ tidy_ps = PrefixCon (tidy_con con pat_ty ex_tvs ps)
- -- mk_pat picks a WildPat of the appropriate type for absent fields,
- -- and the specified pattern for present fields
- mk_pat (arg_ty, lbl) = case [pat | (sel_id,pat,_) <- rpats,
- recordSelectorFieldLabel sel_id == lbl
- ] of
- (pat:pats) -> ASSERT( null pats )
- pat
- [] -> WildPat arg_ty
-
-tidy1 v (ListPat ty pats) match_result
- = returnDs (list_ConPat, match_result)
+tidy1 v (ListPat pats ty) match_result
+ = returnDs (unLoc list_ConPat, match_result)
where
- list_ty = mkListTy ty
- list_ConPat
- = foldr (\ x -> \y -> ConPat consDataCon list_ty [] [] [x, y])
- (ConPat nilDataCon list_ty [] [] [])
- pats
+ list_ty = mkListTy ty
+ list_ConPat = foldr (\ x y -> mkPrefixConPat consDataCon [x, y] list_ty)
+ (mkNilPat list_ty)
+ pats
-- introduce fake parallel array constructors to be able to handle parallel
-- arrays with the existing machinery for constructor pattern
--
-tidy1 v (PArrPat ty pats) match_result
- = returnDs (parrConPat, match_result)
+tidy1 v (PArrPat pats ty) match_result
+ = returnDs (unLoc parrConPat, match_result)
where
arity = length pats
- parrConPat = ConPat (parrFakeCon arity) (mkPArrTy ty) [] [] pats
+ parrConPat = mkPrefixConPat (parrFakeCon arity) pats (mkPArrTy ty)
tidy1 v (TuplePat pats boxity) match_result
- = returnDs (tuple_ConPat, match_result)
+ = returnDs (unLoc tuple_ConPat, match_result)
where
arity = length pats
- tuple_ConPat
- = ConPat (tupleCon boxity arity)
- (mkTupleTy boxity arity (map outPatType pats)) [] []
- pats
+ tuple_ConPat = mkPrefixConPat (tupleCon boxity arity) pats
+ (mkTupleTy boxity arity (map hsPatType pats))
tidy1 v (DictPat dicts methods) match_result
= case num_of_d_and_ms of
0 -> tidy1 v (TuplePat [] Boxed) match_result
- 1 -> tidy1 v (head dict_and_method_pats) match_result
+ 1 -> tidy1 v (unLoc (head dict_and_method_pats)) match_result
_ -> tidy1 v (TuplePat dict_and_method_pats Boxed) match_result
where
num_of_d_and_ms = length dicts + length methods
- dict_and_method_pats = map VarPat (dicts ++ methods)
+ dict_and_method_pats = map nlVarPat (dicts ++ methods)
-- LitPats: we *might* be able to replace these w/ a simpler form
-tidy1 v pat@(LitPat lit lit_ty) match_result
- = returnDs (tidyLitPat lit pat, match_result)
+tidy1 v pat@(LitPat lit) match_result
+ = returnDs (unLoc (tidyLitPat lit (noLoc pat)), match_result)
-- NPats: we *might* be able to replace these w/ a simpler form
-tidy1 v pat@(NPat lit lit_ty _) match_result
- = returnDs (tidyNPat lit lit_ty pat, match_result)
+tidy1 v pat@(NPatOut lit lit_ty _) match_result
+ = returnDs (unLoc (tidyNPat lit lit_ty (noLoc pat)), match_result)
-- and everything else goes through unchanged...
tidy1 v non_interesting_pat match_result
= returnDs (non_interesting_pat, match_result)
+
+
+tidy_con data_con pat_ty ex_tvs (PrefixCon ps) = ps
+tidy_con data_con pat_ty ex_tvs (InfixCon p1 p2) = [p1,p2]
+tidy_con data_con pat_ty ex_tvs (RecCon rpats)
+ | null rpats
+ = -- Special case for C {}, which can be used for
+ -- a constructor that isn't declared to have
+ -- fields at all
+ map (noLoc.WildPat) con_arg_tys'
+
+ | otherwise
+ = map mk_pat tagged_arg_tys
+ where
+ -- Boring stuff to find the arg-tys of the constructor
+ inst_tys = tcTyConAppArgs pat_ty -- Newtypes must be opaque
+ con_arg_tys' = dataConInstOrigArgTys data_con (inst_tys ++ mkTyVarTys ex_tvs)
+ tagged_arg_tys = con_arg_tys' `zip` (dataConFieldLabels data_con)
+
+ -- mk_pat picks a WildPat of the appropriate type for absent fields,
+ -- and the specified pattern for present fields
+ mk_pat (arg_ty, lbl) =
+ case [ pat | (sel_id,pat) <- rpats,
+ recordSelectorFieldLabel (unLoc sel_id) == lbl
+ ] of
+ (pat:pats) -> ASSERT( null pats )
+ pat
+ [] -> noLoc (WildPat arg_ty)
\end{code}
\noindent
\begin{code}
matchSigPat :: [Id] -> EquationInfo -> DsM MatchResult
-matchSigPat (var:vars) (EqnInfo n ctx (SigPat pat ty co_fn : pats) result)
- = selectMatchVar pat `thenDs` \ new_var ->
- dsExpr (HsApp co_fn (HsVar var)) `thenDs` \ rhs ->
- match (new_var:vars) [EqnInfo n ctx (pat:pats) result] `thenDs` \ result' ->
+matchSigPat (var:vars) (EqnInfo n ctx (SigPatOut pat ty co_fn : pats) result)
+ = selectMatchVarL pat `thenDs` \ new_var ->
+ dsExpr (HsApp (noLoc co_fn) (nlHsVar var)) `thenDs` \ rhs ->
+ match (new_var:vars) [EqnInfo n ctx (unLoc pat:pats) result] `thenDs` \ result' ->
returnDs (adjustMatchResult (bindNonRec new_var rhs) result')
\end{code}
\end{enumerate}
\begin{code}
-matchWrapper :: TypecheckedMatchContext -- For shadowing warning messages
- -> [TypecheckedMatch] -- Matches being desugared
+matchWrapper :: HsMatchContext Name -- For shadowing warning messages
+ -> [LMatch Id] -- Matches being desugared
-> DsM ([Id], CoreExpr) -- Results
\end{code}
EqnInfo _ _ arg_pats _ : _ = eqns_info
error_string = matchContextErrString ctxt
in
- mapDs selectMatchVar arg_pats `thenDs` \ new_vars ->
+ mappM selectMatchVar arg_pats `thenDs` \ new_vars ->
match_fun dflags new_vars eqns_info `thenDs` \ match_result ->
mkErrorAppDs pAT_ERROR_ID result_ty error_string `thenDs` \ fail_expr ->
\begin{code}
matchSimply :: CoreExpr -- Scrutinee
- -> TypecheckedMatchContext -- Match kind
- -> TypecheckedPat -- Pattern it should match
+ -> HsMatchContext Name -- Match kind
+ -> LPat Id -- Pattern it should match
-> CoreExpr -- Return this if it matches
-> CoreExpr -- Return this if it doesn't
-> DsM CoreExpr
matchSimply scrut kind pat result_expr fail_expr
- = getSrcLocDs `thenDs` \ locn ->
+ = getSrcSpanDs `thenDs` \ locn ->
let
- ctx = DsMatchContext kind [pat] locn
+ ctx = DsMatchContext kind [unLoc pat] locn
match_result = cantFailMatchResult result_expr
in
matchSinglePat scrut ctx pat match_result `thenDs` \ match_result' ->
extractMatchResult match_result' fail_expr
-matchSinglePat :: CoreExpr -> DsMatchContext -> TypecheckedPat
+matchSinglePat :: CoreExpr -> DsMatchContext -> LPat Id
-> MatchResult -> DsM MatchResult
matchSinglePat (Var var) ctx pat match_result
= getDOptsDs `thenDs` \ dflags ->
- match_fn dflags [var] [EqnInfo 1 ctx [pat] match_result]
+ match_fn dflags [var] [EqnInfo 1 ctx [unLoc pat] match_result]
where
match_fn dflags
| dopt Opt_WarnSimplePatterns dflags = matchExport
| otherwise = match
matchSinglePat scrut ctx pat match_result
- = selectMatchVar pat `thenDs` \ var ->
+ = selectMatchVarL pat `thenDs` \ var ->
matchSinglePat (Var var) ctx pat match_result `thenDs` \ match_result' ->
returnDs (adjustMatchResult (bindNonRec var scrut) match_result')
\end{code}
This is actually local to @matchWrapper@.
\begin{code}
-flattenMatches :: TypecheckedMatchContext
- -> [TypecheckedMatch]
+flattenMatches :: HsMatchContext Name
+ -> [LMatch Id]
-> DsM (Type, [EquationInfo])
flattenMatches kind matches
ASSERT( all (tcEqType result_ty) result_tys )
returnDs (result_ty, eqn_infos)
where
- flatten_match (Match pats _ grhss, n)
- = dsGRHSs kind pats grhss `thenDs` \ (ty, match_result) ->
- getSrcLocDs `thenDs` \ locn ->
- returnDs (ty, EqnInfo n (DsMatchContext kind pats locn) pats match_result)
+ flatten_match (L _ (Match pats _ grhss), n)
+ = dsGRHSs kind upats grhss `thenDs` \ (ty, match_result) ->
+ getSrcSpanDs `thenDs` \ locn ->
+ returnDs (ty, EqnInfo n (DsMatchContext kind upats locn) upats match_result)
+ where upats = map unLoc pats
\end{code}