Use visit_fn_{pre,post} to avoid going past lambdas during writeback instead of explicitly casing.

Author: msullivan

src/comp/middle/typeck.rs

@@ -966,13 +966,8 @@ mod writeback {
     fn visit_stmt_pre(@fn_ctxt fcx, &@ast::stmt s) {
         resolve_type_vars_for_node(fcx, s.span, ty::stmt_node_id(s));
     }
-    fn visit_expr_pre(@mutable bool ignore, @fn_ctxt fcx, &@ast::expr e) {
+    fn visit_expr_pre(@fn_ctxt fcx, &@ast::expr e) {
         resolve_type_vars_for_node(fcx, e.span, e.id);
-        alt (e.node) {
-            // We don't want to recurse down into lambdas.
-            case (ast::expr_fn(_)) { *ignore = true; }
-            case (_) { }
-        }
     }
     fn visit_expr_post(@mutable bool ignore, &@ast::expr e) {
         *ignore = false;
@@ -1000,23 +995,31 @@ mod writeback {
         }
     }
     fn resolve_type_vars_in_block(&@fn_ctxt fcx, &ast::block block) {
-        // A trick to ignore any contained items.
-
+        // A trick to ignore any contained items and lambdas.
         auto ignore = @mutable false;
         fn visit_item_pre(@mutable bool ignore, &@ast::item item) {
             *ignore = true;
         }
         fn visit_item_post(@mutable bool ignore, &@ast::item item) {
             *ignore = false;
         }
+        fn visit_fn_pre(@mutable bool ignore, &ast::_fn f, &span sp,
+                        &ast::fn_ident i, ast::node_id d) {
+            *ignore = true;
+        }
+        fn visit_fn_post(@mutable bool ignore, &ast::_fn f, &span sp,
+                         &ast::fn_ident i, ast::node_id d) {
+            *ignore = false;
+        }
         fn keep_going(@mutable bool ignore) -> bool { ret !*ignore; }
         auto visit =
             rec(keep_going=bind keep_going(ignore),
                 visit_item_pre=bind visit_item_pre(ignore, _),
                 visit_item_post=bind visit_item_post(ignore, _),
+                visit_fn_pre=bind visit_fn_pre(ignore, _, _, _, _),
+                visit_fn_post=bind visit_fn_post(ignore, _, _, _, _),
                 visit_stmt_pre=bind visit_stmt_pre(fcx, _),
-                visit_expr_pre=bind visit_expr_pre(ignore, fcx, _),
-                visit_expr_post=bind visit_expr_post(ignore, _),
+                visit_expr_pre=bind visit_expr_pre(fcx, _),
                 visit_block_pre=bind visit_block_pre(fcx, _),
                 visit_pat_pre=bind visit_pat_pre(fcx, _),
                 visit_local_pre=bind visit_local_pre(fcx, _)