[project @ 2005-10-14 11:22:41 by simonpj]

[ghc-hetmet.git] / ghc / compiler / deSugar / MatchCon.lhs

diff --git a/ghc/compiler/deSugar/MatchCon.lhs b/ghc/compiler/deSugar/MatchCon.lhs
index da59300..7988c2c 100644 (file)
--- a/ghc/compiler/deSugar/MatchCon.lhs
+++ b/ghc/compiler/deSugar/MatchCon.lhs
@@ -12,7 +12,7 @@ import {-# SOURCE #-} Match   ( match )
 
 import HsSyn           ( Pat(..), HsConDetails(..) )
 import DsBinds         ( dsLHsBinds )
-import DataCon         ( isVanillaDataCon, dataConTyVars, dataConOrigArgTys )
+import DataCon         ( isVanillaDataCon, dataConTyVars, dataConInstOrigArgTys )
 import TcType          ( tcTyConAppArgs )
 import Type            ( substTys, zipTopTvSubst, mkTyVarTys )
 import CoreSyn
@@ -134,8 +134,7 @@ match_con vars ty eqns
        -- Get the arg types, which we use to type the new vars
        -- to match on, from the "outside"; the types of pats1 may 
        -- be more refined, and hence won't do
-    arg_tys = substTys (zipTopTvSubst (dataConTyVars con) inst_tys)
-                      (dataConOrigArgTys con)
+    arg_tys = dataConInstOrigArgTys con inst_tys
     inst_tys | isVanillaDataCon con = tcTyConAppArgs pat_ty    -- Newtypes opaque!
             | otherwise            = mkTyVarTys tvs1
 \end{code}