Expose internal properties of map/set iterators via mirrors.

src/mirror-debugger.js

 // Copyright 2006-2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Handle id counters.
 var next_handle_ = 0;
 var next_transient_handle_ = -1;
 
 // Mirror cache.
 var mirror_cache_ = [];
@@ skipping 901 matching lines @@
       result.push(new InternalPropertyMirror("[[TargetFunction]]",
                                              bindings[0]));
       result.push(new InternalPropertyMirror("[[BoundThis]]", bindings[1]));
       var boundArgs = [];
       for (var i = 2; i < bindings.length; i++) {
         boundArgs.push(bindings[i]);
       }
       result.push(new InternalPropertyMirror("[[BoundArgs]]", boundArgs));
     }
     return result;
+  } else if (IS_MAP_ITERATOR(value) || IS_SET_ITERATOR(value)) {
+    var details = IS_MAP_ITERATOR(value) ? %MapIteratorDetails(value)
+                                         : %SetIteratorDetails(value);
+    var kind;
+    switch (details[2]) {
+      case 1: kind = "keys"; break;
+      case 2: kind = "values"; break;
+      case 3: kind = "entries"; break;
+    }
+    var result = [];
+    result.push(new InternalPropertyMirror("[[IteratorHasMore]]", details[0]));
+    result.push(new InternalPropertyMirror("[[IteratorIndex]]", details[1]));
+    if (kind) {
+      result.push(new InternalPropertyMirror("[[IteratorKind]]", kind));
+    }
+    return result;
   } else if (ObjectIsPromise(value)) {
     var result = [];
     result.push(new InternalPropertyMirror("[[PromiseStatus]]",
                                            PromiseGetStatus_(value)));
     result.push(new InternalPropertyMirror("[[PromiseValue]]",
                                            PromiseGetValue_(value)));
     return result;
   }
   return [];
 }
@@ skipping 2082 matching lines @@
   }
   if (!NUMBER_IS_FINITE(value)) {
     if (value > 0) {
       return 'Infinity';
     } else {
       return '-Infinity';
     }
   }
   return value;
 }