diff options
Diffstat (limited to 'compiler/GHC/Tc/Gen/Match.hs')
| -rw-r--r-- | compiler/GHC/Tc/Gen/Match.hs | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/compiler/GHC/Tc/Gen/Match.hs b/compiler/GHC/Tc/Gen/Match.hs index b68e0db87c..d978f5dbf3 100644 --- a/compiler/GHC/Tc/Gen/Match.hs +++ b/compiler/GHC/Tc/Gen/Match.hs @@ -157,10 +157,17 @@ tcMatchLambda herald match_ctxt match res_ty -- @tcGRHSsPat@ typechecks @[GRHSs]@ that occur in a @PatMonoBind@. -tcGRHSsPat :: GRHSs GhcRn (LHsExpr GhcRn) -> TcRhoType +tcGRHSsPat :: GRHSs GhcRn (LHsExpr GhcRn) -> ExpRhoType -> TcM (GRHSs GhcTc (LHsExpr GhcTc)) -- Used for pattern bindings -tcGRHSsPat grhss res_ty = tcGRHSs match_ctxt grhss (mkCheckExpType res_ty) +tcGRHSsPat grhss res_ty + = tcScalingUsage Many $ + -- Like in tcMatchesFun, this scaling happens because all + -- let bindings are unrestricted. A difference, here, is + -- that when this is not the case, any more, we will have to + -- make sure that the pattern is strict, otherwise this will + -- desugar to incorrect code. + tcGRHSs match_ctxt grhss res_ty where match_ctxt = MC { mc_what = PatBindRhs, mc_body = tcBody } |