Properly keep track of whether normalising given or wanted dicts

[ghc-hetmet.git] / compiler / typecheck / TcPat.lhs

diff --git a/compiler/typecheck/TcPat.lhs b/compiler/typecheck/TcPat.lhs
index c2f758d..10946f3 100644 (file)
--- a/compiler/typecheck/TcPat.lhs
+++ b/compiler/typecheck/TcPat.lhs
@@ -637,17 +637,21 @@ tcConPat pstate con_span data_con tycon pat_ty arg_pats thing_inside
          then do { -- The common case; no class bindings etc 
                     -- (see Note [Arrows and patterns])
                    (arg_pats', inner_tvs, res) <- tcConArgs data_con arg_tys' 
-                                                              arg_pats pstate thing_inside
+                                                   arg_pats pstate thing_inside
                  ; let res_pat = ConPatOut { pat_con = L con_span data_con, 
-                                             pat_tvs = [], pat_dicts = [], pat_binds = emptyLHsBinds,
-                                             pat_args = arg_pats', pat_ty = pat_ty' }
+                                             pat_tvs = [], pat_dicts = [], 
+                                              pat_binds = emptyLHsBinds,
+                                             pat_args = arg_pats', 
+                                              pat_ty = pat_ty' }
 
                    ; return (wrap_res_pat res_pat, inner_tvs, res) }
 
          else do   -- The general case, with existential, and local equality 
                     -- constraints
        { let eq_preds = [mkEqPred (mkTyVarTy tv, ty) | (tv, ty) <- eq_spec]
-             theta'   = substTheta tenv (full_theta ++ eq_preds)
+             theta'   = substTheta tenv (eq_preds ++ full_theta)
+                           -- order is *important* as we generate the list of
+                           -- dictionary binders from theta'
              ctxt     = pat_ctxt pstate
        ; checkTc (case ctxt of { ProcPat -> False; other -> True })
                  (existentialProcPat data_con)