diff --git a/components/keysnail-loader.js b/components/keysnail-loader.js
index 6a85057..1bde0fa 100644
--- a/components/keysnail-loader.js
+++ b/components/keysnail-loader.js
@@ -113,7 +113,7 @@ KeySnailLoader.prototype = {
 
         let context = win.KeySnail.modules;
 
-        for (let [, module] in Iterator(modules))
+        for (let module of modules)
             loadModule(module, context);
     },
 
@@ -122,7 +122,7 @@ KeySnailLoader.prototype = {
                      "password1Container",
                      "password2Container"];
 
-        for (let [, id] in Iterator(ids))
+        for (let id of ids)
         {
             let elem = aDocument.getElementById(id);
             if (elem && !elem.hidden)
diff --git a/content/keysnail.js b/content/keysnail.js
index 76ea8d7..d43ab20 100644
--- a/content/keysnail.js
+++ b/content/keysnail.js
@@ -101,7 +101,7 @@
                 _ = modules._;
             } catch (x) {}
 
-            for (let [, name] in Iterator(moduleObjects))
+            for (let name of moduleObjects)
                 this.initModule(name);
 
             // set modules
diff --git a/content/modules/ext.js b/content/modules/ext.js
index 46198a5..07a7c3c 100755
--- a/content/modules/ext.js
+++ b/content/modules/ext.js
@@ -25,7 +25,7 @@ var ext = function () {
         }
         keyList = keyList.sort();
 
-        for (let [, name] in Iterator(keyList))
+        for (let name of keyList)
             extList.push([name, exts[name].description || ""]);
 
         return extList;
diff --git a/content/modules/hook.js b/content/modules/hook.js
index 6565c6c..9b45e0c 100755
--- a/content/modules/hook.js
+++ b/content/modules/hook.js
@@ -54,7 +54,7 @@ var hook = {
         if (!hook)
             return;
 
-        for (let [i, action] in Iterator(hook)) {
+        for (let [i, action] of util.keyValues(hook)) {
             try {
                 action(arg);
             } catch (x) {
diff --git a/content/modules/key.js b/content/modules/key.js
index 84c4682..c4474f3 100755
--- a/content/modules/key.js
+++ b/content/modules/key.js
@@ -371,8 +371,8 @@ var key = {
 
         this.passAllKeys = true;
 
-        for (let [, keyStr] in Iterator(aKeys)) {
-            for (let [, type] in Iterator(aType)) {
+        for (let keyStr of aKeys) {
+            for (let type of aType) {
                 util.message("feed " + keyStr);
                 let event = this.stringToKeyEvent(keyStr, true, type, true);
                 // event.ksNoHandle becomes undefined while propagating
@@ -1049,7 +1049,7 @@ var key = {
         var aTarget = this.keyMapHolder[aTargetKeyMapName];
         var aDestination = this.keyMapHolder[aDestinationKeyMapName];
 
-        for (let [property, value] in Iterator(aTarget))
+        for (let [property, value] of util.keyValues(aTarget))
             aDestination[property] = value;
     },
 
@@ -1104,7 +1104,7 @@ var key = {
         if (!(aKeyMapName instanceof Array))
             aKeyMapName = [aKeyMapName];
 
-        for (let [, keyMapName] in Iterator(aKeyMapName))
+        for (let keyMapName of aKeyMapName)
         {
             var addTo = this.keyMapHolder[keyMapName];
 
@@ -1348,7 +1348,7 @@ var key = {
         if (!aKeySequence)
             aKeySequence = [];
 
-        for (let [keyStr, cont] in Iterator(aKeyMap))
+        for (let [keyStr, cont] of util.keyValues(aKeyMap))
         {
             switch (typeof cont)
             {
diff --git a/content/modules/macro.js b/content/modules/macro.js
index 9fd0575..779cd25 100755
--- a/content/modules/macro.js
+++ b/content/modules/macro.js
@@ -34,7 +34,7 @@ var macro = {
         var len = aEvents.length;
         var sleepTime = this.sleepTime;
 
-        for (let [, event] in Iterator(aEvents))
+        for (let event of aEvents)
         {
             if (event.keyCode === KeyEvent.DOM_VK_TAB)
             {
diff --git a/content/modules/plugins.js b/content/modules/plugins.js
index 14aea24..dffb90d 100644
--- a/content/modules/plugins.js
+++ b/content/modules/plugins.js
@@ -17,7 +17,7 @@ var plugins = {
     setupOptions: function (prefix, defaults, pluginInfo) {
         let options = {};
 
-        for (let [name, { preset, description, type, hidden }] in Iterator(defaults)) {
+        for (let [name, { preset, description, type, hidden }] of util.keyValues(defaults)) {
             let fullName = prefix + "." + name;
 
             // XXX: bind values
@@ -107,7 +107,7 @@ var plugins = {
     getInstalledPlugins: function () {
         let pluginList = {};
 
-        for (let [pluginPath, pluginContext] in Iterator(plugins.context)) {
+        for (let [pluginPath, pluginContext] of util.keyValues(plugins.context)) {
             let isDisabled      = userscript.isDisabledPlugin(pluginPath);
             let isNotCompatible = pluginContext.__ksNotCompatible__;
 
diff --git a/content/modules/prompt.js b/content/modules/prompt.js
index 416b3cb..354c378 100755
--- a/content/modules/prompt.js
+++ b/content/modules/prompt.js
@@ -164,19 +164,19 @@ var prompt = function () {
     function $E(aName, aAttributes) {
         let elem = document.createElement(aName);
 
-        for (let [k, v] in Iterator(aAttributes))
+      for (let [k, v] of util.keyValues(aAttributes))
             elem.setAttribute(k, v);
 
         return elem;
     }
 
     function implant(a, b) {
-        for (let [k, v] in Iterator(b))
+        for (let [k, v] of util.keyValues(b))
             a[k] = v;
     }
 
     function implantAll(a, b) {
-        for (let k in util.getAllPropertyNames(b)) {
+        for (let k of util.getAllPropertyNames(b)) {
             try {
                 a[k] = b[k];
             } catch (_) {}
@@ -193,10 +193,10 @@ var prompt = function () {
         var newObject = {};
         var key;
 
-        for (let [key, value] in Iterator(a))
+        for (let [key, value] of util.keyValues(a))
             newObject[key] = value;
 
-        for (let [key, value] in Iterator(b))
+        for (let [key, value] of util.keyValues(b))
             newObject[key] = value;
 
         return newObject;
@@ -210,7 +210,7 @@ var prompt = function () {
 
     function getActualCols(aCols) {
         if (gFlags)
-            for (let [, flag] in Iterator(gFlags))
+            for (let flag of gFlags)
                 if (flag & (HIDDEN | ICON)) aCols--;
         return aCols;
     }
@@ -259,7 +259,7 @@ var prompt = function () {
     function setColumns(aColumn) {
         if (gFlags)
         {
-            for (let [, flag] in Iterator(gFlags))
+            for (let flag of gFlags)
             {
                 if (flag & (HIDDEN | ICON))
                     aColumn--;
@@ -726,7 +726,7 @@ var prompt = function () {
             var found   = {};
             var uniqStr = "";
 
-            for (let [, c] in Iterator(str))
+            for (let c of str)
             {
                 if (found[c])
                     continue;
@@ -749,7 +749,7 @@ var prompt = function () {
 
         var continuousMode = false;
 
-        for (let [, opt] in Iterator(uniq(opts)))
+        for (let opt of uniq(opts))
         {
             switch (opt)
             {
@@ -1016,7 +1016,7 @@ var prompt = function () {
         if (typeof aActions === "function")
             aActions = [[aActions, "Default callback"]];
 
-        for (let [i, action] in Iterator(aActions))
+        for (let [i, action] of util.keyValues(aActions))
         {
             var item = document.createElement("menuitem");
             item.setAttribute("label", action[1]);
@@ -1047,7 +1047,7 @@ var prompt = function () {
         );
 
         function stick(keymap) {
-            for (let [k, a] in Iterator(keymap))
+            for (let [k, a] of util.keyValues(keymap))
             {
                 let act  = a.split(",")[0];
                 let desc = actionDescriptionMap[act] || "";
@@ -1091,7 +1091,7 @@ var prompt = function () {
         var list = [];
 
         // create action list and local command
-        for (let [i, action] in Iterator(aActions))
+        for (let [i, action] of util.keyValues(aActions))
         {
             let index = i + 1;
             list.push([action[0], index.toString() + ". " + action[1]]);
@@ -1456,7 +1456,7 @@ var prompt = function () {
                 let buffer   = [];
                 let escapeIt = false;
 
-                for (let [, c] in Iterator(str))
+                for (let c of str)
                 {
                     if (!escapeIt && c === escapeChar)
                         escapeIt = true;
@@ -1734,7 +1734,7 @@ var prompt = function () {
                     collection : null
                 };
 
-                for (let [, cmpltr] in Iterator(completers))
+                for (let cmpltr of completers)
                 {
                     let tmpCc      = cmpltr(currentText, text) || {collection : null};
                     let collection = tmpCc.collection;
@@ -1749,7 +1749,7 @@ var prompt = function () {
 
                 let max = -1;
 
-                for (let [, c] in Iterator(collections))
+                for (let c of collections)
                 {
                     let first = c[0];
 
@@ -1964,12 +1964,12 @@ var prompt = function () {
                                 "watch"                : undefined
                             };
 
-                            for (let k in Iterator(objectPrototype, true))
+                            for (let k of Object.keys(objectPrototype))
                                 objectPrototype[k] = Object[k];
 
                             let functionPrototype = {__proto__ : objectPrototype};
 
-                            for (let [, k] in Iterator(["apply", "call", "toSource", "toString", "valueOf"]))
+                            for (let  k of ["apply", "call", "toSource", "toString", "valueOf"])
                                 functionPrototype[k] = Function[k];
 
                             let globalObjects = {
@@ -1994,11 +1994,11 @@ var prompt = function () {
                                 URIError       : []
                             };
 
-                            for (let [objName, keys] in Iterator(globalObjects))
+                            for (let [objName, keys] of util.keyValues(globalObjects))
                             {
                                 globalObjects[objName] = {};
 
-                                for ([, k] in Iterator(keys))
+                                for (k of keys)
                                 {
                                     globalObjects[objName][k] = global[objName][k];
                                 }
@@ -2826,7 +2826,7 @@ var prompt = function () {
                     hook.removeHook('KeySnailInitialized', onInitialized);
                     let displayHelpKey = [];
 
-                    for (let [k, act] in Iterator(actionKeys.selector))
+                    for (let [k, act] of util.keyValues(actionKeys.selector))
                     {
                         if (act === "prompt-display-keymap-help")
                             displayHelpKey.push(k);
diff --git a/content/modules/shell.js b/content/modules/shell.js
index 029876e..4dbdaa9 100644
--- a/content/modules/shell.js
+++ b/content/modules/shell.js
@@ -317,7 +317,7 @@ var shell =
           * @param {} b
           */
          function implant(a, b) {
-             for (let [k, v] in Iterator(a))
+             for (let [k, v] of util.keyValues(a))
                  b[k] = v;
 
              return b;
@@ -480,7 +480,7 @@ var shell =
                                  //     if user input
                                  //        "h" <TAB>
                                  //     returned item is will be "hoge".
-                                 for ([name, cmd] in Iterator(commands))
+                                 for (let [name, cmd] of util.keyValues(commands))
                                  {
                                      if (name.indexOf(left) === 0)
                                      {
diff --git a/content/modules/userscript.js b/content/modules/userscript.js
index ddf8f48..40839a5 100755
--- a/content/modules/userscript.js
+++ b/content/modules/userscript.js
@@ -777,7 +777,7 @@ var userscript = {
             main: "chrome://browser/content/browser.xul"
         };
 
-        for (let [, entry] in Iterator(includeURIs))
+        for (let entry of includeURIs)
         {
             uri = replacePair[entry] || entry;
 
@@ -785,7 +785,7 @@ var userscript = {
                 return false;
         }
 
-        for (let [, entry] in Iterator(excludeURIs))
+        for (let entry of excludeURIs)
         {
             uri = replacePair[entry] || entry;
 
@@ -1320,7 +1320,7 @@ var userscript = {
 
         var maxLen = Math.max.apply(null, [for (str of keys) str.length]);
 
-        for (let [, key] in Iterator(keys))
+        for (let key of keys)
         {
             var setting = settings[key] || "undefined";
             var padding = Math.max(maxLen - key.length, 0) + 2;
@@ -1335,7 +1335,7 @@ var userscript = {
             return;
         }
 
-        for (let [, setting] in Iterator(aScheme.hooks))
+        for (let setting of aScheme.hooks)
         {
             let [name, body] = setting;
             if (!name || !body)
@@ -1376,7 +1376,7 @@ var userscript = {
         function getFunction(aCommand) {
             if (typeof aCommand === "string")
             {
-                for (let [, commands] in Iterator(builtin))
+                for (let commands of util.values(builtin))
                 {
                     if (commands[aCommand])
                         return commands[aCommand][0].toString();
@@ -1420,7 +1420,7 @@ var userscript = {
 
             var settings = aScheme.keybindings[mode];
 
-            for (let [, setting] in Iterator(settings))
+            for (let setting of settings)
             {
                 if (!setting)
                     continue;
diff --git a/content/modules/util.js b/content/modules/util.js
index afd1345..fda11b3 100755
--- a/content/modules/util.js
+++ b/content/modules/util.js
@@ -35,7 +35,7 @@ var util = function () {
 
                 // partially borrowed from bookmarks.js of liberator
                 ensureAliases : function (aEngines) {
-                    for (let [, engine] in Iterator(aEngines))
+                    for (let engine of aEngines)
                     {
                         if (!engine.alias)
                         {
@@ -633,7 +633,7 @@ var util = function () {
          */
         setPrefs:
         function setPrefs(aPrefList) {
-            for (let [key, value] in Iterator(aPrefList))
+            for (let [key, value] of util.keyValues(aPrefList))
                 this.setPref(key, value);
         },
 
@@ -1257,7 +1257,7 @@ var util = function () {
             if (opts.mimeType)
                 req.overrideMimeType(opts.mimeType);
 
-            for (let [name, value] in Iterator(opts.header || {}))
+            for (let [name, value] of util.keyValue(opts.header || {}))
                 req.setRequestHeader(name, value);
 
             req.send(util.paramsToString(params) || null);
@@ -1529,7 +1529,7 @@ var util = function () {
                 if ("getOwnPropertyNames" in Object) {
                     let encountered = { __proto__ : null };
 
-                    for (let [, k] in Iterator(Object.getOwnPropertyNames(obj)))
+                    for (let k of Object.getOwnPropertyNames(obj))
                         try {
                             encountered[k] = true;
                             yield k;
@@ -1559,17 +1559,20 @@ var util = function () {
         sortMultiple: function ([a], [b]) { return (a < b) ? -1 : (a > b) ? 1 : 0; },
 
         find: function (array, pred) {
-            for (let [i, v] in Iterator(array))
+            for (let [i, v] of util.keyValues(array)) {
                 if (pred(v, i))
                     return v;
+            }
+            return undefined;
         },
 
         findAll: function (array, pred) {
             let res = [];
 
-            for (let [i, v] in Iterator(array))
+            for (let [i, v] of util.keyValues(array)) {
                 if (pred(v, i))
-                    res.push(v);
+                  res.push(v);
+            }
 
             return res.length ? res : null;
         },
diff --git a/content/modules/vimp.js b/content/modules/vimp.js
index 92e44e0..0c4995a 100644
--- a/content/modules/vimp.js
+++ b/content/modules/vimp.js
@@ -351,7 +351,7 @@ shell.add("dia[log]", "Open a dialog",
 
               try
               {
-                  for (let [, dialog] in Iterator(dialogs))
+                  for (let dialog of dialogs)
                   {
                       if (dialog[0].toLowerCase() === arg.toLowerCase())
                       {
@@ -404,7 +404,7 @@ function getRemotePluginListCached(purgeCache) {
     return remotePluginListCache;
 }
 function getRemotePluginInfoByPluginName(pluginName) {
-    for (let [, remotePluginInfo] in Iterator(getRemotePluginListCached()))
+    for (let remotePluginInfo of getRemotePluginListCached())
         if (remotePluginInfo.leafName === pluginName)
             return remotePluginInfo;
     return null;
diff --git a/content/pluginmanager.js b/content/pluginmanager.js
index 8bad062..45b0958 100644
--- a/content/pluginmanager.js
+++ b/content/pluginmanager.js
@@ -41,11 +41,11 @@ let ksPluginManager = (function () {
         let elem = document.createElement(name);
 
         if (attrs)
-            for (let [k, v] in Iterator(attrs))
+            for (let [k, v] of util.keyValues(attrs))
                 elem.setAttribute(k, v);
 
         if (childs)
-            for (let [, child] in Iterator(childs))
+            for (let child of childs)
                 elem.appendChild(child);
 
         return elem;
@@ -414,7 +414,7 @@ let ksPluginManager = (function () {
     function updateDisabledPluginList() {
         var disabledPlugins = [];
 
-        for (let [pluginPath, ] in Iterator(pluginInfoHolder)) {
+        for (let pluginPath of Object.keys(pluginInfoHolder)) {
             if (pluginInfoHolder[pluginPath].status === KS_PLUGIN_DISABLED) {
                 disabledPlugins.push(pluginPath);
             }
diff --git a/content/preference.js b/content/preference.js
index 5b4bc6f..2931b43 100644
--- a/content/preference.js
+++ b/content/preference.js
@@ -91,7 +91,7 @@ var ksPreference = {
     setPluginUpdaterIntervalFieldState: function (enabled) {
         let box = document.getElementById("plugin-updater-interval");
 
-        for (let [, elem] in Iterator(box.childNodes))
+        for (let elem of box.childNodes)
             elem.disabled = !enabled;
     },
 
diff --git a/content/rcwizard.js b/content/rcwizard.js
index b01203b..2152b9a 100644
--- a/content/rcwizard.js
+++ b/content/rcwizard.js
@@ -68,7 +68,7 @@
             let self = this;
 
             this.getSchemeFiles(function (files) {
-                for (let [, leaf] in Iterator(files.map(function (f) f.leafName)))
+                for (let leaf of files.map(function (f) f.leafName))
                 {
                     try
                     {
diff --git a/plugins/_color-theme-solarized.ks.js b/plugins/_color-theme-solarized.ks.js
index f93cc9a..bc7d674 100644
--- a/plugins/_color-theme-solarized.ks.js
+++ b/plugins/_color-theme-solarized.ks.js
@@ -86,8 +86,8 @@ let PLUGIN_INFO =
     style.js["undefined"] = color($red);
     style.js["null"]      = color($cyan);
 
-    for (let [prefix, opts] in Iterator(ooo))
-        for (let [k, v] in Iterator(opts))
+    for (let [prefix, opts] of util.keyValues(ooo))
+        for (let [k, v] of util.keyValues(opts))
             plugins.options[prefix + "." + k] = arrange(v);
 
     let colorThemeSolarized = arrange('\
diff --git a/plugins/_dark-theme.ks.js b/plugins/_dark-theme.ks.js
index fb040a8..34692af 100644
--- a/plugins/_dark-theme.ks.js
+++ b/plugins/_dark-theme.ks.js
@@ -78,8 +78,8 @@ let PLUGIN_INFO =
      style.js["undefined"] = "color:#e000a5;";
      style.js["null"]      = "color:#07d8a8;";
 
-     for (let [prefix, opts] in Iterator(ooo))
-         for (let [k, v] in Iterator(opts))
+     for (let [prefix, opts] of util.keyValues(ooo))
+         for (let [k, v] of util.keyValues(opts))
              plugins.options[prefix + "." + k] = arrange(v);
 
      let darkTheme = arrange(<><![CDATA[
diff --git a/plugins/_xul-growl.ks.js b/plugins/_xul-growl.ks.js
index c58d154..a4f54f0 100755
--- a/plugins/_xul-growl.ks.js
+++ b/plugins/_xul-growl.ks.js
@@ -286,7 +286,7 @@ var xulGrowl =
                                     style={panelStyle} xmlns={xulNS}/>),
 
              getIndexAndMessageByCount: function (count) {
-                 for (let [i, gm] in Iterator(this.gmList))
+                 for (let [i, gm] of util.keyValues(this.gmList))
                  {
                      if (count == gm.count)
                          return [i, gm];
diff --git a/plugins/builtin-commands-ext.ks.js b/plugins/builtin-commands-ext.ks.js
index ebe1652..9bd1dc5 100644
--- a/plugins/builtin-commands-ext.ks.js
+++ b/plugins/builtin-commands-ext.ks.js
@@ -125,8 +125,8 @@ function main() {
         return;
     }
 
-    for (let [, commands] in Iterator(context.ksBuiltin)) {
-        for (var name in commands) {
+    for (let commands of util.keyValues(context.ksBuiltin)) {
+        for (let name of Object.keys(commands)) {
             var ename = propertyToExtName(name);
 
 
diff --git a/plugins/dabbrev.ks.js b/plugins/dabbrev.ks.js
index bb5a774..389fdd7 100644
--- a/plugins/dabbrev.ks.js
+++ b/plugins/dabbrev.ks.js
@@ -123,7 +123,7 @@ let dabbrev =
 
              popup.setAttribute("ignorekeys", "true");
 
-             for (let [i, text] in Iterator(items))
+             for (let [i, text] of util.keyValues(items))
              {
                  let item = document.createElement("menuitem");
                  item.setAttribute("label", text);
diff --git a/plugins/dmacro.ks.js b/plugins/dmacro.ks.js
index 889bbca..3962fc0 100644
--- a/plugins/dmacro.ks.js
+++ b/plugins/dmacro.ks.js
@@ -246,7 +246,7 @@ let dmacro =
          function play(aEvents) {
              var len = aEvents.length;
 
-             for (let [, event] in Iterator(aEvents))
+             for (let event of aEvents)
              {
                  let target  = macro.getCurrentFocusedElement();
                  let fakedEv = {originalTarget : target};
diff --git a/plugins/hok.ks.js b/plugins/hok.ks.js
index 766ddf2..d6aaa15 100644
--- a/plugins/hok.ks.js
+++ b/plugins/hok.ks.js
@@ -566,7 +566,7 @@ function followRel(doc, rel, pattern) {
         doc.querySelectorAll(pOptions["follow_link_candidate_selector"])
     );
 
-    for (let [, elem] in Iterator(relLinkCandidates.reverse())) {
+    for (let elem of relLinkCandidates.reverse()) {
         if (relLinkPattern.test(elem.textContent) ||
             relLinkPattern.test(elem.alt) ||
             relLinkPattern.test(elem.title)) {
@@ -736,7 +736,7 @@ var hok = function () {
         }
 
         var hints = [];
-        for (let [hint] in Iterator(reverseHints)) {
+        for (let hint of Object.keys(reverseHints)) {
             hints.push(hint);
         }
 
@@ -897,7 +897,7 @@ var hok = function () {
         var hintSpan = doc.createElement('span');
 
         let st = hintSpan.style;
-        for (let [prop, value] in Iterator(hintBaseStyle))
+        for (let [prop, value] of util.keyValues(hintBaseStyle))
             st[formatPropertyName(prop)] = value;
         st.backgroundColor = hintColorLink;
 
@@ -1016,7 +1016,7 @@ var hok = function () {
         const hideUnmatchedHint = pOptions["hide_unmatched_hint"];
         let foundCount = 0;
 
-        for (let [hintStr, hintElem] in Iterator(hintElements)) {
+        for (let [hintStr, hintElem] of util.keyValues(hintElements)) {
             hintStr = String(hintStr);
             if (hintStr.indexOf(inputKey) === 0) {
                 if (hintStr != inputKey)
@@ -1033,7 +1033,7 @@ var hok = function () {
     }
 
     function resetHintsColor() {
-        for (let [, span] in Iterator(hintElements)) {
+        for (let span of util.values(hintElements)) {
             span.style.backgroundColor = getHintColor(span.element);
             span.style.display = "inline";
         }
@@ -1188,8 +1188,8 @@ var hok = function () {
         let currentPageURL = content.location.href;
         if (pOptions["local_queries"] && currentPageURL)
         {
-            for (let [, [targetURLPattern, localSelector, toOverride]]
-                 in Iterator(pOptions["local_queries"]))
+            for (let [targetURLPattern, localSelector, toOverride]
+                 of pOptions["local_queries"])
             {
                 if (currentPageURL.match(targetURLPattern))
                 {
@@ -1254,7 +1254,7 @@ var hok = function () {
                     try
                     {
                         // TODO: Is there a good way to do this?
-                        for (let [, hintElem] in Iterator(hintElements))
+                        for (let hintElem of util.values(hintElements))
                         {
                             if (supressUniqueFire)
                                 hintElem.element.focus();
diff --git a/plugins/kkk.ks.js b/plugins/kkk.ks.js
index 798e2a7..078fb81 100644
--- a/plugins/kkk.ks.js
+++ b/plugins/kkk.ks.js
@@ -127,12 +127,12 @@ let kkk =
              },
 
              start: function () {
-                 for (let [, type] in Iterator(eventType))
+                 for (let type of eventType)
                      window.addEventListener(type, preventEvent, true);
              },
 
              stop: function () {
-                 for (let [, type] in Iterator(eventType))
+                 for (let type of eventType)
                      window.removeEventListener(type, preventEvent, true);
              }
          };
diff --git a/plugins/metaplus.ks.js b/plugins/metaplus.ks.js
index de41921..ace9066 100644
--- a/plugins/metaplus.ks.js
+++ b/plugins/metaplus.ks.js
@@ -104,12 +104,12 @@ function getOption(aName) {
         return aName in optionsDefaultValue ? optionsDefaultValue[aName] : undefined;
 }
 
-for (let [mode, keymap] in Iterator(key.keyMapHolder))
+for (let [mode, keymap] of util.keyValues(key.keyMapHolder))
 {
     if (!keymap)
         continue;
 
-    for (let [k, f] in Iterator(keymap))
+    for (let [k, f] of util.keyValues(keymap))
     {
         let matched = k.match(/^(C-)?M-(.+)/);
         if (matched)
diff --git a/plugins/yet-another-twitter-client-keysnail.ks.js b/plugins/yet-another-twitter-client-keysnail.ks.js
index 8992486..d69872b 100755
--- a/plugins/yet-another-twitter-client-keysnail.ks.js
+++ b/plugins/yet-another-twitter-client-keysnail.ks.js
@@ -524,11 +524,11 @@ const $U = {
         let elem = document.createElement(name);
 
         if (attrs)
-            for (let [k, v] in Iterator(attrs))
+            for (let [k, v] of util.keyValues(attrs))
                 elem.setAttribute(k, v);
 
         if (childs)
-            for (let [, v] in Iterator(childs))
+            for (let v of childs)
                 elem.appendChild(v);
 
         return elem;
@@ -1048,7 +1048,7 @@ OAuth.prototype = {
         if (options.parameters && message.method === "POST")
         {
             outer:
-            for (let [, params] in Iterator(options.parameters))
+            for (let params of options.parameters)
             {
                 for (let i = 0; i < message.parameters; ++i)
                 {
@@ -1112,7 +1112,7 @@ const twitterAPI = {
 
         let action = proto.action;
 
-        for (let [k, v] in Iterator(args))
+        for (let [k, v] of util.keyValues(args))
             if (typeof v !== "undefined")
                 action = action.replace(util.format("{%s}", k), $U.encodeOAuth(v), "g");
 
@@ -1629,7 +1629,7 @@ var twitterClient =
                 window.addEventListener("unload", function () {
                     self.stop();
 
-                    for (let [, win] in Iterator(Notifier.getBrowserWindows()))
+                    for (let win of Notifier.getBrowserWindows())
                     {
                         try
                         {
@@ -1792,7 +1792,7 @@ var twitterClient =
         if (!share.twitterTrackingInfo)
             share.twitterTrackingInfo = persist.restore("yatck_tracking_info") || {};
 
-        for (let [name, info] in Iterator(share.twitterTrackingInfo))
+        for (let [name, info] of util.keyValues(share.twitterTrackingInfo))
         {
             if (!share.twitterTrackingInfo[name])
                 share.twitterTrackingInfo[name] = {};
@@ -2585,7 +2585,7 @@ var twitterClient =
             let listOrigin  = document.getElementById(HEAD_LIST_ORIGIN);
             let listButtons = {};
 
-            for (let [, crawler] in Iterator(gLists))
+            for (let crawler of util.values(gLists))
             {
                 let button = document.createElement("toolbarbutton");
 
@@ -2608,7 +2608,7 @@ var twitterClient =
             let searchOrigin    = document.getElementById(HEAD_SEARCH_ORIGIN);
             let trackingButtons = {};
 
-            for (let [, crawler] in Iterator(gTrackings))
+            for (let crawler of util.values(gTrackings))
             {
                 let name    = crawler.name;
                 let keyword = crawler.nameEscaped;
@@ -3588,7 +3588,7 @@ var twitterClient =
             ["entities", "media"].forEach(function (entityContainerName) {
                 let entityContainer = status[entityContainerName];
                 if (status[entityContainerName]) {
-                    for (let [entityName, entity] in Iterator(entityContainer)) {
+                    for (let [entityName, entity] of util.keyValues(entityContainer)) {
                         entities[entityName] = entity;
                     }
                 }
@@ -3614,7 +3614,7 @@ var twitterClient =
                     retweetedMessageNode.removeChild(retweetedMessageNode.firstChild);
                 }
 
-                for (let [, childNode] in Iterator(newChildren)) {
+                for (let childNode of newChildren) {
                     retweetedMessageNode.appendChild(childNode);
                 }
 
@@ -3999,7 +3999,7 @@ var twitterClient =
             if (!gStatuses.cache)
                 return;
 
-            for (let [, status] in Iterator(gStatuses.cache))
+            for (let status of gStatuses.cache)
                 if (status.id_str === aId)
                     proc(status);
         }
@@ -4383,7 +4383,7 @@ var twitterClient =
             updateListButton: function () {
                 let listButtons = my.twitterClientHeader.listButtons;
 
-                for (let [, crawler] in Iterator(gLists))
+                for (let crawler of gLists)
                 {
                     if (crawler.name in listButtons && crawler.cache && crawler.cache.length)
                     {
@@ -4397,7 +4397,7 @@ var twitterClient =
             updateTrackingButton: function () {
                 let trackingButtons = my.twitterClientHeader.trackingButtons;
 
-                for (let [, crawler] in Iterator(gTrackings))
+                for (let crawler of util.values(gTrackings))
                 {
                     if (crawler.name in trackingButtons && crawler.cache && crawler.cache.length)
                     {
@@ -4575,7 +4575,7 @@ var twitterClient =
 
         if (pOptions["automatically_begin_list"])
         {
-            for (let [, crawler] in Iterator(gLists))
+            for (let crawler of gLists)
             {
                 if (crawler.cache)
                     continue;
@@ -4587,7 +4587,7 @@ var twitterClient =
 
         if (pOptions["automatically_begin_tracking"])
         {
-            for (let [, crawler] in Iterator(gTrackings))
+            for (let crawler of util.keyValues(gTrackings))
             {
                 if (crawler.cache)
                     continue;
diff --git a/share/WikiParser.js b/share/WikiParser.js
index e34850d..8b6c0ce 100644
--- a/share/WikiParser.js
+++ b/share/WikiParser.js
@@ -109,7 +109,6 @@ WikiParser.prototype = {
         }
     },
     parse: function(){
-        var ite = Iterator(this.lines);
         var num, line, indent;
         var currentIndent = 0, indentList = [0], nest=0;
         var prevMode = "";
@@ -117,7 +116,7 @@ WikiParser.prototype = {
         var stack = [];
         var prevNode;
         //try {
-        for ([num, line] in ite){
+        for ([num, line] of util.keyValues(this.lines)){
             [,indent, line] = line.match(/^(\s*)(.*)\s*$/);
             currentIndent = indent.length;
             var prevIndent = indentList[indentList.length -1];
diff --git a/share/share.js b/share/share.js
index 4cb7de7..59fef34 100644
--- a/share/share.js
+++ b/share/share.js
@@ -243,7 +243,7 @@ function hookApplicationQuit() {
 
     quitObserver.prototype = {
         observe: function(subject, topic, data) {
-            for (let [name, obj] in Iterator(persist.registeredObjects))
+            for (let [name, obj] of util.keyValues(persist.registeredObjects))
             {
                 persist.preserve(obj, name);
             }
diff --git a/stub/hit-a-hint.ks.js b/stub/hit-a-hint.ks.js
index a44b4ac..a90bd2a 100644
--- a/stub/hit-a-hint.ks.js
+++ b/stub/hit-a-hint.ks.js
@@ -396,11 +396,11 @@ var ksHah = new function () {
         let type = elem.type;
 
         if (elem instanceof HTMLInputElement && /(submit|button|reset)/.test(type)) {
-            return [elem.value, false];   
+            return [elem.value, false];
         }
         else
         {
-            for (let [, option] in Iterator(options["hintinputs"].split(",")))
+            for (let option of options["hintinputs"].split(","))
             {
                 if (option == "value")
                 {
@@ -641,7 +641,7 @@ var ksHah = new function () {
         let activeHint = hintNumber || 1;
         validHints = [];
 
-        for (let [,{ doc: doc, start: start, end: end }] in Iterator(docs))
+        for (let { doc: doc, start: start, end: end } of docs)
         {
             let [scrollX, scrollY] = getBodyOffsets(doc);
 
@@ -701,7 +701,7 @@ var ksHah = new function () {
         {
             let css = [];
             // FIXME: Broken for imgspans.
-            for (let [, { doc: doc }] in Iterator(docs))
+            for (let { doc: doc } of docs)
             {
                 for (let elem in evaluateXPath("//*[@keysnail:highlight and @number]", doc))
                 {
@@ -727,7 +727,7 @@ var ksHah = new function () {
     {
         let firstElem = validHints[0] || null;
 
-        for (let [,{ doc: doc, start: start, end: end }] in Iterator(docs))
+        for (let { doc: doc, start: start, end: end } of docs)
         {
             for (let elem in evaluateXPath("//*[@keysnail:highlight='hints']", doc))
                 elem.parentNode.removeChild(elem);
@@ -987,7 +987,7 @@ var ksHah = new function () {
             function stringsAtBeginningOfWords(strings, words, allowWordOverleaping)
             {
                 let strIdx = 0;
-                for (let [, word] in Iterator(words))
+                for (let word of words)
                 {
                     if (word.length == 0)
                         continue;