Cosmetics in SpecConstr

SpecConstr currently uses substExpr for tiresome reasons to do with
GADTs.  Unfortunately the substExpr generates some WARNINGS (when DEBUG)
is on, because we aren't adding all the in-scope Ids to the in-scope
set of the substitution.

When we move to FC these substExprs will go away, so I'm not going to
worry about this now.

diff --git a/compiler/specialise/SpecConstr.lhs b/compiler/specialise/SpecConstr.lhs
index 74944da..7541a93 100644 (file)
--- a/compiler/specialise/SpecConstr.lhs
+++ b/compiler/specialise/SpecConstr.lhs
@@ -262,6 +262,9 @@ extendCaseBndrs env case_bndr scrut con@(DataAlt data_con) alt_bndrs
                   map varToCoreExpr alt_bndrs
 
     gadt_args = map (substExpr subst . varToCoreExpr) alt_bndrs
+       -- This call generates some bogus warnings from substExpr,
+       -- because it's inconvenient to put all the Ids in scope
+       -- Will be fixed when we move to FC
 
     (alt_tvs, _) = span isTyVar alt_bndrs
     Just (tv_subst, is_local) = coreRefineTys data_con alt_tvs (idType case_bndr)
@@ -463,7 +466,7 @@ specialise env fn bndrs body (SCU {calls=calls, occs=occs})
        good_calls = [ pats
                     | (con_env, call_args) <- all_calls,
                       call_args `lengthAtLeast` n_bndrs,           -- App is saturated
-                      let call = (bndrs `zip` call_args),
+                      let call = bndrs `zip` call_args,
                       any (good_arg con_env occs) call,    -- At least one arg is a constr app
                       let (_, pats) = argsToPats con_env us call_args
                     ]