diff --git a/ghc/compiler/typecheck/TcMatches.lhs b/ghc/compiler/typecheck/TcMatches.lhs
index be45c99e8fa662c41cd27fa97c8160de7929ac63..82dd55dcd4e3bb381afee9f61a0262b8120af981 100644
--- a/ghc/compiler/typecheck/TcMatches.lhs
+++ b/ghc/compiler/typecheck/TcMatches.lhs
@@ -6,7 +6,7 @@
\begin{code}
#include "HsVersions.h"
-module TcMatches ( tcMatchesFun, tcMatchesCase, tcMatch ) where
+module TcMatches ( tcMatchesFun, tcMatchesCase, tcMatchExpected ) where
IMP_Ubiq()
@@ -21,15 +21,15 @@ import HsSyn ( Match(..), GRHSsAndBinds(..), GRHS(..), InPat,
Sig, HsLit, DoOrListComp, Fixity, HsType, ArithSeqInfo,
collectPatBinders, pprMatch )
import RnHsSyn ( SYN_IE(RenamedMatch) )
-import TcHsSyn ( TcIdOcc(..), SYN_IE(TcMatch) )
+import TcHsSyn ( SYN_IE(TcMatch) )
import TcMonad
import Inst ( Inst, SYN_IE(LIE), plusLIE )
import TcEnv ( newMonoIds )
import TcPat ( tcPat )
-import TcType ( SYN_IE(TcType), TcMaybe, zonkTcType )
+import TcType ( TcIdOcc(..), SYN_IE(TcType), TcMaybe, zonkTcType )
import TcSimplify ( bindInstsOfLocalFuns )
-import Unify ( unifyTauTy, unifyTauTyList )
+import Unify ( unifyTauTy, unifyTauTyList, unifyFunTy )
import Name ( Name {- instance Outputable -} )
import Kind ( Kind, mkTypeKind )
@@ -114,20 +114,6 @@ tcMatchesExpected expected_ty fun_or_case (match1 : matches)
) `thenTc` \ (match1', lie1) ->
tcMatchesExpected expected_ty fun_or_case matches `thenTc` \ (matches', lie2) ->
returnTc (match1' : matches', plusLIE lie1 lie2)
-
-tcMatches :: [RenamedMatch] -> TcM s ([TcMatch s], LIE s, [TcType s])
-
-tcMatches [match]
- = tcAddSrcLoc (get_Match_loc match) $
- tcMatch match `thenTc` \ (match', lie, ty) ->
- returnTc ([match'], lie, [ty])
-
-tcMatches (match1 : matches)
- = tcAddSrcLoc (get_Match_loc match1) (
- tcMatch match1
- ) `thenTc` \ (match1', lie1, match1_ty) ->
- tcMatches matches `thenTc` \ (matches', lie2, matches_ty) ->
- returnTc (match1' : matches', plusLIE lie1 lie2, match1_ty : matches_ty)
\end{code}
\begin{code}
@@ -140,71 +126,42 @@ tcMatchExpected
-- in instead!
tcMatchExpected expected_ty the_match@(PatMatch pat match)
- = case getFunTy_maybe expected_ty of
-
- Nothing -> -- Not a function type (eg type variable)
- -- So use tcMatch instead
- tcMatch the_match `thenTc` \ (match', lie_match, match_ty) ->
- unifyTauTy expected_ty match_ty `thenTc_`
- returnTc (match', lie_match)
-
- Just (arg_ty,rest_ty) -> -- It's a function type!
- let binders = collectPatBinders pat
- in
- newMonoIds binders mkTypeKind (\ mono_ids ->
- tcPat pat `thenTc` \ (pat', lie_pat, pat_ty) ->
- unifyTauTy pat_ty arg_ty `thenTc_`
- tcMatchExpected rest_ty match `thenTc` \ (match', lie_match) ->
-
- -- In case there are any polymorpic, overloaded binders in the pattern
- -- (which can happen in the case of rank-2 type signatures, or data constructors
- -- with polymorphic arguments), we must dd a bindInstsOfLocalFns here
- --
- -- 99% of the time there are no bindings. In the unusual case we
- -- march down the match to dump them in the right place (boring but easy).
- bindInstsOfLocalFuns lie_match mono_ids `thenTc` \ (lie_match', inst_mbinds) ->
- let
- inst_binds = MonoBind inst_mbinds [] False
- match'' = case inst_mbinds of
- EmptyMonoBinds -> match'
- other -> glue_on match'
- glue_on (PatMatch p m) = PatMatch p (glue_on m)
- glue_on (GRHSMatch (GRHSsAndBindsOut grhss binds ty))
- = (GRHSMatch (GRHSsAndBindsOut grhss
- (inst_binds `ThenBinds` binds)
- ty))
- glue_on (SimpleMatch expr) = SimpleMatch (HsLet inst_binds expr)
- in
- returnTc (PatMatch pat' match'',
- plusLIE lie_pat lie_match')
- )
+ = unifyFunTy expected_ty `thenTc` \ (arg_ty, rest_ty) ->
+
+ let binders = collectPatBinders pat
+ in
+ newMonoIds binders mkTypeKind (\ mono_ids ->
+ tcPat pat `thenTc` \ (pat', lie_pat, pat_ty) ->
+ unifyTauTy pat_ty arg_ty `thenTc_`
+ tcMatchExpected rest_ty match `thenTc` \ (match', lie_match) ->
+ -- In case there are any polymorpic, overloaded binders in the pattern
+ -- (which can happen in the case of rank-2 type signatures, or data constructors
+ -- with polymorphic arguments), we must do a bindInstsOfLocalFns here
+ --
+ -- 99% of the time there are no bindings. In the unusual case we
+ -- march down the match to dump them in the right place (boring but easy).
+ bindInstsOfLocalFuns lie_match mono_ids `thenTc` \ (lie_match', inst_mbinds) ->
+ let
+ inst_binds = MonoBind inst_mbinds [] False
+ match'' = case inst_mbinds of
+ EmptyMonoBinds -> match'
+ other -> glue_on match'
+ glue_on (PatMatch p m) = PatMatch p (glue_on m)
+ glue_on (GRHSMatch (GRHSsAndBindsOut grhss binds ty))
+ = (GRHSMatch (GRHSsAndBindsOut grhss
+ (inst_binds `ThenBinds` binds)
+ ty))
+ glue_on (SimpleMatch expr) = SimpleMatch (HsLet inst_binds expr)
+ in
+ returnTc (PatMatch pat' match'',
+ plusLIE lie_pat lie_match')
+ )
tcMatchExpected expected_ty (GRHSMatch grhss_and_binds)
- = tcGRHSsAndBinds grhss_and_binds `thenTc` \ (grhss_and_binds', lie, grhss_ty) ->
+ = tcGRHSsAndBinds expected_ty grhss_and_binds `thenTc` \ (grhss_and_binds', lie) ->
checkTc (isTauTy expected_ty)
lurkingRank2SigErr `thenTc_`
- unifyTauTy expected_ty grhss_ty `thenTc_`
returnTc (GRHSMatch grhss_and_binds', lie)
-
-tcMatch :: RenamedMatch -> TcM s (TcMatch s, LIE s, TcType s)
-
-tcMatch (PatMatch pat match)
- = let binders = collectPatBinders pat
- in
- newMonoIds binders mkTypeKind (\ _ ->
- -- NB TypeKind; lambda-bound variables are allowed
- -- to unify with unboxed types.
-
- tcPat pat `thenTc` \ (pat', lie_pat, pat_ty) ->
- tcMatch match `thenTc` \ (match', lie_match, match_ty) ->
- returnTc (PatMatch pat' match',
- plusLIE lie_pat lie_match,
- mkFunTy pat_ty match_ty)
- )
-
-tcMatch (GRHSMatch grhss_and_binds)
- = tcGRHSsAndBinds grhss_and_binds `thenTc` \ (grhss_and_binds', lie, grhss_ty) ->
- returnTc (GRHSMatch grhss_and_binds', lie, grhss_ty)
\end{code}