Various nits.

src/librustc/middle/ty.rs

@@ -678,8 +678,14 @@ pub struct ctxt<'tcx> {
     pub types: CommonTypes<'tcx>,
 
     pub sess: Session,
+
+    // NDM -- can we add a comment explaining the relationship of
+    // these two maps?  Or maybe make partialdefs be a variant of def?
+    // These two maps store the result of path resolution. For any
+    // given path, there will be an entry in one map or the other.
     pub def_map: DefMap,
     pub partial_def_map: PartialDefMap,
+
     pub last_private_map: RefCell<LastPrivateMap>,
 
     pub named_region_map: resolve_lifetime::NamedRegionMap,

src/librustc_resolve/lib.rs

@@ -3513,6 +3513,9 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     path_depth: usize,
                     namespace: Namespace,
                     check_ribs: bool) -> Option<(Def, LastPrivate, usize)> {
+        // NDM                                  ^~~~~~~~~~~~~~~~~~~~~~~~~
+        // NDM this seems like a case for a named struct
+
         let span = path.span;
         let segments = &path.segments[..path.segments.len()-path_depth];
 

src/librustc_typeck/check/mod.rs

@@ -1593,6 +1593,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     {
         let tcx = self.tcx();
 
+        // Nit: call it scheme
         let pty = ty::lookup_item_type(tcx, did);
 
         let substs = astconv::ast_path_substs_for_ty(self, self,
@@ -3609,8 +3610,8 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
           };
 
           // Helpers to avoid keeping the RefCell borrow for too long.
-          let get_def = |&:| tcx.def_map.borrow().get(&id).cloned();
-          let get_partial_def = |&:| tcx.partial_def_map.borrow().get(&id).cloned();
+          let get_def = || tcx.def_map.borrow().get(&id).cloned();
+          let get_partial_def = || tcx.partial_def_map.borrow().get(&id).cloned();
 
           if let Some(def) = get_def() {
               let pty = type_scheme_for_def(fcx, expr.span, def);