Expose the content of Sets and WeakSets through SetMirror.

src/mirror-debugger.js

Index: src/mirror-debugger.js
diff --git a/src/mirror-debugger.js b/src/mirror-debugger.js
index e717f6e0706fc232a2c252deb848b51243871b6e..35f34a91d48edcd1c26e3aa1a54fbbec06731e41 100644
--- a/src/mirror-debugger.js
+++ b/src/mirror-debugger.js
@@ -83,6 +83,8 @@ function MakeMirror(value, opt_transient) {
     mirror = new ScriptMirror(value);
   } else if (IS_MAP(value) || IS_WEAKMAP(value)) {
     mirror = new MapMirror(value);
+  } else if (IS_SET(value) || IS_WEAKSET(value)) {
+    mirror = new SetMirror(value);
   } else if (ObjectIsPromise(value)) {
     mirror = new PromiseMirror(value);
   } else {
@@ -158,6 +160,7 @@ var CONTEXT_TYPE = 'context';
 var SCOPE_TYPE = 'scope';
 var PROMISE_TYPE = 'promise';
 var MAP_TYPE = 'map';
+var SET_TYPE = 'set';
 
 // Maximum length when sending strings through the JSON protocol.
 var kMaxProtocolStringLength = 80;
@@ -214,6 +217,7 @@ var ScopeType = { Global: 0,
 //         - ErrorMirror
 //         - PromiseMirror
 //         - MapMirror
+//         - SetMirror
 //     - PropertyMirror
 //     - InternalPropertyMirror
 //     - FrameMirror
@@ -434,6 +438,15 @@ Mirror.prototype.isMap = function() {
 
 
 /**
+ * Check whether the mirror reflects a set.
+ * @returns {boolean} True if the mirror reflects a set
+ */
+Mirror.prototype.isSet = function() {
+  return this instanceof SetMirror;
+};
+
+
+/**
  * Allocate a handle id for this object.
  */
 Mirror.prototype.allocateHandle_ = function() {
@@ -1304,6 +1317,33 @@ MapMirror.prototype.entries = function() {
 };
 
 
+function SetMirror(value) {
+  %_CallFunction(this, value, SET_TYPE, ObjectMirror);
+}
+inherits(SetMirror, ObjectMirror);
+
+
+/**
+ * Returns an array of elements of a set.
+ * This will keep elements alive for WeakSets.
+ *
+ * @returns {Array.<Object>} Array of elements of a set.
+ */
+SetMirror.prototype.values = function() {
+  if (IS_WEAKSET(this.value_)) {
+    return %GetWeakSetValues(this.value_);
+  }
+
+  var result = [];
+  var iter = %_CallFunction(this.value_, builtins.SetValues);
+  var next;
+  while (!(next = iter.next()).done) {
+    result.push(next.value);
+  }
+  return result;
+};
+
+
 /**
  * Base mirror object for properties.
  * @param {ObjectMirror} mirror The mirror object having this property