diff --git a/mithril.js b/mithril.js
index 96dc3db9..91348bb4 100644
--- a/mithril.js
+++ b/mithril.js
@@ -1,10 +1,6 @@
 Mithril = m = new function app(window, undefined) {
-	var sObj = "[object Object]", sArr = "[object Array]", sStr = "[object String]"
-	function type(obj) {return {}.toString.call(obj)}
-	function isObj(obj) {return obj != null && type(obj) == sObj}
-	function isArr(obj) {return type(obj) == sArr}
-	function isFn(obj) {return typeof obj == "function"}
-	function isStr(obj){ return type(obj) == sStr}
+	var sObj = "[object Object]", sArr = "[object Array]", sStr = "[object String]", sFn = "function"
+	var type = {}.toString
 	var parser = /(?:(^|#|\.)([^#\.\[\]]+))|(\[.+?\])/g, attrParser = /\[(.+?)(?:=("|'|)(.*?)\2)?\]/
 	var voidElements = /AREA|BASE|BR|COL|COMMAND|EMBED|HR|IMG|INPUT|KEYGEN|LINK|META|PARAM|SOURCE|TRACK|WBR/
 
@@ -23,7 +19,7 @@ Mithril = m = new function app(window, undefined) {
 	 */
 	function m() {
 		var args = [].slice.call(arguments)
-		var hasAttrs = isObj(args[1]) && !("tag" in args[1]) && !("subtree" in args[1])
+		var hasAttrs = args[1] != null && type.call(args[1]) == sObj && !("tag" in args[1]) && !("subtree" in args[1])
 		var attrs = hasAttrs ? args[1] : {}
 		var classAttrName = "class" in attrs ? "class" : "className"
 		var cell = {tag: "div", attrs: {}}
@@ -41,7 +37,7 @@ Mithril = m = new function app(window, undefined) {
 
 
 		var children = hasAttrs ? args[2] : args[1]
-		if (isArr(children)) {
+		if (type.call(children) == sArr) {
 			cell.children = children
 		}
 		else {
@@ -82,7 +78,7 @@ Mithril = m = new function app(window, undefined) {
 		//- it simplifies diffing code
 		if (data == null) data = ""
 		if (data.subtree === "retain") return cached
-		var cachedType = type(cached), dataType = type(data)
+		var cachedType = type.call(cached), dataType = type.call(data)
 		if (cached == null || cachedType != dataType) {
 			if (cached != null) {
 				if (parentCache && parentCache.nodes) {
@@ -176,7 +172,7 @@ Mithril = m = new function app(window, undefined) {
 					//the second clause (after the pipe) matches text nodes
 					subArrayCount += (item.match(/<[^\/]|\>\s*[^<]/g) || []).length
 				}
-				else subArrayCount += isArr(item) ? item.length : 1
+				else subArrayCount += type.call(item) == sArr ? item.length : 1
 				cached[cacheCount++] = item
 			}
 			if (!intact) {
@@ -202,12 +198,14 @@ Mithril = m = new function app(window, undefined) {
 		else if (data != null && dataType == sObj) {
 			if (!data.attrs) data.attrs = {}
 			if (!cached.attrs) cached.attrs = {}
+			
+			var dataAttrKeys = Object.keys(data.attrs)
 			//if an element is different enough from the one in cache, recreate it
-			if (data.tag != cached.tag || Object.keys(data.attrs).join() != Object.keys(cached.attrs).join() || data.attrs.id != cached.attrs.id) {
-				clear(cached.nodes)
-				if (cached.configContext && isFn(cached.configContext.onunload)) cached.configContext.onunload()
+			if (data.tag != cached.tag || dataAttrKeys.join() != Object.keys(cached.attrs).join() || data.attrs.id != cached.attrs.id) {
+				if (cached.nodes.length) clear(cached.nodes)
+				if (cached.configContext && typeof cached.configContext.onunload == sFn) cached.configContext.onunload()
 			}
-			if (!isStr(data.tag)) return
+			if (type.call(data.tag) != sStr) return
 
 			var node, isNew = cached.nodes.length === 0
 			if (data.attrs.xmlns) namespace = data.attrs.xmlns
@@ -218,23 +216,26 @@ Mithril = m = new function app(window, undefined) {
 				cached = {
 					tag: data.tag,
 					//set attributes first, then create children
-					attrs: setAttributes(node, data.tag, data.attrs, {}, namespace),
-					children: build(node, data.tag, undefined, undefined, data.children, cached.children, true, 0, data.attrs.contenteditable ? node : editable, namespace, configs),
+					attrs: dataAttrKeys.length ? setAttributes(node, data.tag, data.attrs, {}, namespace) : {},
+					children: data.children != null && data.children.length > 0 ?
+						build(node, data.tag, undefined, undefined, data.children, cached.children, true, 0, data.attrs.contenteditable ? node : editable, namespace, configs) :
+						data.children,
 					nodes: [node]
 				}
+				if (cached.children && !cached.children.nodes) cached.children.nodes = []
 				//edge case: setting value on <select> doesn't work before children exist, so set it again after children have been created
 				if (data.tag == "select" && data.attrs.value) setAttributes(node, data.tag, {value: data.attrs.value}, {}, namespace)
 				parentElement.insertBefore(node, parentElement.childNodes[index] || null)
 			}
 			else {
 				node = cached.nodes[0]
-				setAttributes(node, data.tag, data.attrs, cached.attrs, namespace)
+				if (dataAttrKeys.length) setAttributes(node, data.tag, data.attrs, cached.attrs, namespace)
 				cached.children = build(node, data.tag, undefined, undefined, data.children, cached.children, false, 0, data.attrs.contenteditable ? node : editable, namespace, configs)
 				cached.nodes.intact = true
 				if (shouldReattach === true && node != null) parentElement.insertBefore(node, parentElement.childNodes[index] || null)
 			}
 			//schedule configs to be called. They are called after `build` finishes running
-			if (isFn(data.attrs["config"])) {
+			if (typeof data.attrs["config"] == sFn) {
 				var context = cached.configContext = cached.configContext || {}
 
 				// bind
@@ -246,7 +247,7 @@ Mithril = m = new function app(window, undefined) {
 				configs.push(callback(data, [node, !isNew, context, cached]))
 			}
 		}
-		else if (!isFn(dataType)) {
+		else if (typeof dataType != sFn) {
 			//handle text nodes
 			var nodes
 			if (cached.nodes.length === 0) {
@@ -301,11 +302,11 @@ Mithril = m = new function app(window, undefined) {
 					//we don't ignore `key` because it must be unique and having it on the DOM helps debugging
 					if (attrName === "config") continue
 					//hook event handlers to the auto-redrawing system
-					else if (isFn(dataAttr) && attrName.indexOf("on") == 0) {
+					else if (typeof dataAttr == sFn && attrName.indexOf("on") == 0) {
 						node[attrName] = autoredraw(dataAttr, node)
 					}
 					//handle `style: {...}`
-					else if (attrName === "style" && isObj(dataAttr)) {
+					else if (attrName === "style" && dataAttr != null && type.call(dataAttr) == sObj) {
 						for (var rule in dataAttr) {
 							if (cachedAttr == null || cachedAttr[rule] !== dataAttr[rule]) node.style[rule] = dataAttr[rule]
 						}
@@ -346,9 +347,9 @@ Mithril = m = new function app(window, undefined) {
 		if (nodes.length != 0) nodes.length = 0
 	}
 	function unload(cached) {
-		if (cached.configContext && isFn(cached.configContext.onunload)) cached.configContext.onunload()
+		if (cached.configContext && typeof cached.configContext.onunload == sFn) cached.configContext.onunload()
 		if (cached.children) {
-			if (isArr(cached.children)) {
+			if (type.call(cached.children) == sArr) {
 				for (var i = 0; i < cached.children.length; i++) unload(cached.children[i])
 			}
 			else if (cached.children.tag) unload(cached.children)
@@ -375,13 +376,19 @@ Mithril = m = new function app(window, undefined) {
 		return nodes
 	}
 	function flatten(data) {
-		var flattened = []
-		for (var i = 0; i < data.length; i++) {
-			var item = data[i]
-			if (isArr(item)) flattened.push.apply(flattened, flatten(item))
-			else flattened.push(item)
+		var index = 0
+		loop: while (true) {
+			for (var i = index; i < data.length; i++) {
+				var item = data[i]
+				if (type.call(data[i]) == sArr) {
+					index = i
+					data = data.concat.apply([], data)
+					continue loop
+				}
+			}
+			break
 		}
-		return flattened
+		return data
 	}
 	function autoredraw(callback, object) {
 		return function(e) {
@@ -449,7 +456,7 @@ Mithril = m = new function app(window, undefined) {
 
 	m.prop = function (store) {
 		//note: using non-strict equality check here because we're checking if store is null OR undefined
-		if ((isObj(store) || isFn(store)) && isFn(store.then)) {
+		if (((store != null && type.call(store) == sObj) || typeof store == sFn) && typeof store.then == sFn) {
 			return propify(store)
 		}
 
@@ -462,7 +469,7 @@ Mithril = m = new function app(window, undefined) {
 		var index = roots.indexOf(root)
 		if (index < 0) index = roots.length
 		var isPrevented = false
-		if (controllers[index] && isFn(controllers[index].onunload)) {
+		if (controllers[index] && typeof controllers[index].onunload == sFn) {
 			var event = {
 				preventDefault: function() {isPrevented = true}
 			}
@@ -541,7 +548,7 @@ Mithril = m = new function app(window, undefined) {
 	m.route = function() {
 		//m.route()
 		if (arguments.length === 0) return currentRoute
-		else if (arguments.length === 3 && isStr(arguments[1])) {
+		else if (arguments.length === 3 && type.call(arguments[1]) == sStr) {
 			var root = arguments[0], defaultRoute = arguments[1], router = arguments[2]
 			redirect = function(source) {
 				var path = currentRoute = normalizeRoute(source)
@@ -568,9 +575,9 @@ Mithril = m = new function app(window, undefined) {
 			element.addEventListener("click", routeUnobtrusive)
 		}
 		//m.route(route)
-		else if (isStr(arguments[0])) {
+		else if (type.call(arguments[0]) == sStr) {
 			currentRoute = arguments[0]
-			var querystring = isObj(arguments[1]) ? buildQueryString(arguments[1]) : null
+			var querystring = arguments[1] != null && type.call(arguments[1]) == sObj ? buildQueryString(arguments[1]) : null
 			if (querystring) currentRoute += (currentRoute.indexOf("?") === -1 ? "?" : "&") + querystring
 
 			var shouldReplaceHistoryEntry = (arguments.length == 3 ? arguments[2] : arguments[1]) === true
@@ -633,7 +640,7 @@ Mithril = m = new function app(window, undefined) {
 		var str = []
 		for(var prop in object) {
 			var key = prefix ? prefix + "[" + prop + "]" : prop, value = object[prop]
-			str.push(isObj(value) ? buildQueryString(value, key) : encodeURIComponent(key) + "=" + encodeURIComponent(value))
+			str.push(value != null && type.call(value) == sObj ? buildQueryString(value, key) : encodeURIComponent(key) + "=" + encodeURIComponent(value))
 		}
 		return str.join("&")
 	}
@@ -719,7 +726,7 @@ Mithril = m = new function app(window, undefined) {
 		}
 
 		function thennable(then, successCallback, failureCallback, notThennableCallback) {
-			if ((isObj(promiseValue) || isFn(promiseValue)) && isFn(then)) {
+			if (((promiseValue != null && type.call(promiseValue) == sObj) || typeof promiseValue == sFn) && typeof then == sFn) {
 				try {
 					// count protects against abuse calls from spec checker
 					var count = 0
@@ -763,10 +770,10 @@ Mithril = m = new function app(window, undefined) {
 				fire()
 			}, function() {
 				try {
-					if (state == RESOLVING && isFn(successCallback)) {
+					if (state == RESOLVING && typeof successCallback == sFn) {
 						promiseValue = successCallback(promiseValue)
 					}
-					else if (state == REJECTING && isFn(failureCallback)) {
+					else if (state == REJECTING && typeof failureCallback == "function") {
 						promiseValue = failureCallback(promiseValue)
 						state = RESOLVING
 					}
@@ -792,7 +799,7 @@ Mithril = m = new function app(window, undefined) {
 		}
 	}
 	m.deferred.onerror = function(e) {
-		if (type(e) == "[object Error]" && !e.constructor.toString().match(/ Error/)) throw e
+		if (type.call(e) == "[object Error]" && !e.constructor.toString().match(/ Error/)) throw e
 	}
 
 	m.sync = function(args) {
@@ -880,12 +887,12 @@ Mithril = m = new function app(window, undefined) {
 			if (options.deserialize == JSON.parse) {
 				xhr.setRequestHeader("Accept", "application/json, text/*");
 			}
-			if (isFn(options.config)) {
+			if (typeof options.config == sFn) {
 				var maybeXhr = options.config(xhr, options)
 				if (maybeXhr != null) xhr = maybeXhr
 			}
 
-			if (options.data && (!isStr(options.data) && options.data.constructor != window.FormData)) throw "Request data should be either be a string or FormData. Check the `serialize` option in `m.request`"
+			if (options.data && (type.call(options.data) != sStr && options.data.constructor != window.FormData)) throw "Request data should be either be a string or FormData. Check the `serialize` option in `m.request`"
 			xhr.send(options.method == "GET" || !options.data ? "" : options.data)
 			return xhr
 		}
@@ -928,7 +935,7 @@ Mithril = m = new function app(window, undefined) {
 				var unwrap = (e.type == "load" ? xhrOptions.unwrapSuccess : xhrOptions.unwrapError) || identity
 				var response = unwrap(deserialize(extract(e.target, xhrOptions)))
 				if (e.type == "load") {
-					if (isArr(response) && xhrOptions.type) {
+					if (type.call(response) == sArr && xhrOptions.type) {
 						for (var i = 0; i < response.length; i++) response[i] = new xhrOptions.type(response[i])
 					}
 					else if (xhrOptions.type) response = new xhrOptions.type(response)