mithril source code without routing and ajax features for performance testing purpose

simple mithriljs

/* global Promise */

;(function (global, factory) { // eslint-disable-line
	"use strict"
	/* eslint-disable no-undef */
	var m = factory(global)
	if (typeof module === "object" && module != null && module.exports) {
		module.exports = m
	} else if (typeof define === "function" && define.amd) {
		define(function () { return m })
	} else {
		global.m = m
	}
	/* eslint-enable no-undef */
})(typeof window !== "undefined" ? window : this, function (global, undefined) { // eslint-disable-line
	"use strict"

	m.version = function () {
		return "v0.2.5"
	}

	var hasOwn = {}.hasOwnProperty
	var type = {}.toString

	function isFunction(object) {
		return typeof object === "function"
	}

	function isObject(object) {
		return type.call(object) === "[object Object]"
	}

	function isString(object) {
		return type.call(object) === "[object String]"
	}

	var isArray = Array.isArray || function (object) {
		return type.call(object) === "[object Array]"
	}

	function noop() {}

	var voidElements = {
		AREA: 1,
		BASE: 1,
		BR: 1,
		COL: 1,
		COMMAND: 1,
		EMBED: 1,
		HR: 1,
		IMG: 1,
		INPUT: 1,
		KEYGEN: 1,
		LINK: 1,
		META: 1,
		PARAM: 1,
		SOURCE: 1,
		TRACK: 1,
		WBR: 1
	}

	// caching commonly used variables
	var $document, $location, $requestAnimationFrame, $cancelAnimationFrame

	// self invoking function needed because of the way mocks work
	function initialize(mock) {
		$document = mock.document
		$location = mock.location
		$cancelAnimationFrame = mock.cancelAnimationFrame || mock.clearTimeout
		$requestAnimationFrame = mock.requestAnimationFrame || mock.setTimeout
	}

	// testing API
	m.deps = function (mock) {
		initialize(global = mock || window)
		return global
	}

	m.deps(global)

	/**
	 * @typedef {String} Tag
	 * A string that looks like -> div.classname#id[param=one][param2=two]
	 * Which describes a DOM node
	 */

	function parseTagAttrs(cell, tag) {
		var classes = []
		/* eslint-disable max-len */
		var parser = /(?:(^|#|\.)([^#\.\[\]]+))|(\[(.+?)(?:\s*=\s*("|'|)((?:\\["'\]]|.)*?)\5)?\])/g
		/* eslint-enable max-len */
		var match

		while ((match = parser.exec(tag))) {
			if (match[1] === "" && match[2]) {
				cell.tag = match[2]
			} else if (match[1] === "#") {
				cell.attrs.id = match[2]
			} else if (match[1] === ".") {
				classes.push(match[2])
			} else if (match[3][0] === "[") {
				var attrValue = match[6]
				if (attrValue) attrValue = attrValue.replace(/\\(["'])/g, "$1")
				cell.attrs[match[4]] = attrValue || true
			}
		}

		return classes
	}

	function getVirtualChildren(args, hasAttrs) {
		var children = hasAttrs ? args.slice(1) : args

		if (children.length === 1 && isArray(children[0])) {
			return children[0]
		} else {
			return children
		}
	}

	function assignAttrs(target, attrs, classes) {
		var classAttr = "class" in attrs ? "class" : "className"

		for (var attrName in attrs) {
			if (hasOwn.call(attrs, attrName)) {
				if (attrName === classAttr &&
						attrs[attrName] != null &&
						attrs[attrName] !== "") {
					classes.push(attrs[attrName])
					// create key in correct iteration order
					target[attrName] = ""
				} else {
					target[attrName] = attrs[attrName]
				}
			}
		}

		if (classes.length) target[classAttr] = classes.join(" ")
	}

	/**
	 *
	 * @param {Tag} The DOM node tag
	 * @param {Object=[]} optional key-value pairs to be mapped to DOM attrs
	 * @param {...mNode=[]} Zero or more Mithril child nodes. Can be an array,
	 *                      or splat (optional)
	 */
	function m(tag, pairs) {
		var args = []

		for (var i = 1, length = arguments.length; i < length; i++) {
			args[i - 1] = arguments[i]
		}

		if (isObject(tag)) return parameterize(tag, args)

		if (!isString(tag)) {
			throw new Error("selector in m(selector, attrs, children) should " +
				"be a string")
		}

		var hasAttrs = pairs != null && isObject(pairs) &&
			!("tag" in pairs || "view" in pairs || "subtree" in pairs)

		var attrs = hasAttrs ? pairs : {}
		var cell = {
			tag: "div",
			attrs: {},
			children: getVirtualChildren(args, hasAttrs)
		}

		assignAttrs(cell.attrs, attrs, parseTagAttrs(cell, tag))
		return cell
	}

	function forEach(list, f) {
		for (var i = 0; i < list.length && !f(list[i], i++);) {
			// function called in condition
		}
	}

	function forKeys(list, f) {
		forEach(list, function (attrs, i) {
			return (attrs = attrs && attrs.attrs) &&
				attrs.key != null &&
				f(attrs, i)
		})
	}
	// This function was causing deopts in Chrome.
	function dataToString(data) {
		// data.toString() might throw or return null if data is the return
		// value of Console.log in some versions of Firefox (behavior depends on
		// version)
		try {
			if (typeof data !== "boolean" &&
					data != null &&
					data.toString() != null) return data
		} catch (e) {
			// silently ignore errors
		}
		return ""
	}

	// This function was causing deopts in Chrome.
	function injectTextNode(parentElement, first, index, data) {
		try {
			insertNode(parentElement, first, index)
			first.nodeValue = data
		} catch (e) {
			// IE erroneously throws error when appending an empty text node
			// after a null
		}
	}

	function flatten(list) {
		// recursively flatten array
		for (var i = 0; i < list.length; i++) {
			if (isArray(list[i])) {
				list = list.concat.apply([], list)
				// check current index again and flatten until there are no more
				// nested arrays at that index
				i--
			}
		}
		return list
	}

	function insertNode(parentElement, node, index) {
		parentElement.insertBefore(node,
			parentElement.childNodes[index] || null)
	}

	var DELETION = 1
	var INSERTION = 2
	var MOVE = 3

	function handleKeysDiffer(data, existing, cached, parentElement) {
		forKeys(data, function (key, i) {
			existing[key = key.key] = existing[key] ? {
				action: MOVE,
				index: i,
				from: existing[key].index,
				element: cached.nodes[existing[key].index] ||
					$document.createElement("div")
			} : {action: INSERTION, index: i}
		})

		var actions = []
		for (var prop in existing) {
			if (hasOwn.call(existing, prop)) {
				actions.push(existing[prop])
			}
		}

		var changes = actions.sort(sortChanges)
		var newCached = new Array(cached.length)

		newCached.nodes = cached.nodes.slice()

		forEach(changes, function (change) {
			var index = change.index
			if (change.action === DELETION) {
				clear(cached[index].nodes, cached[index])
				newCached.splice(index, 1)
			}
			if (change.action === INSERTION) {
				var dummy = $document.createElement("div")
				dummy.key = data[index].attrs.key
				insertNode(parentElement, dummy, index)
				newCached.splice(index, 0, {
					attrs: {key: data[index].attrs.key},
					nodes: [dummy]
				})
				newCached.nodes[index] = dummy
			}

			if (change.action === MOVE) {
				var changeElement = change.element
				var maybeChanged = parentElement.childNodes[index]
				if (maybeChanged !== changeElement && changeElement !== null) {
					parentElement.insertBefore(changeElement,
						maybeChanged || null)
				}
				newCached[index] = cached[change.from]
				newCached.nodes[index] = changeElement
			}
		})

		return newCached
	}

	function diffKeys(data, cached, existing, parentElement) {
		var keysDiffer = data.length !== cached.length

		if (!keysDiffer) {
			forKeys(data, function (attrs, i) {
				var cachedCell = cached[i]
				return keysDiffer = cachedCell &&
					cachedCell.attrs &&
					cachedCell.attrs.key !== attrs.key
			})
		}

		if (keysDiffer) {
			return handleKeysDiffer(data, existing, cached, parentElement)
		} else {
			return cached
		}
	}

	function diffArray(data, cached, nodes) {
		// diff the array itself

		// update the list of DOM nodes by collecting the nodes from each item
		forEach(data, function (_, i) {
			if (cached[i] != null) nodes.push.apply(nodes, cached[i].nodes)
		})
		// remove items from the end of the array if the new array is shorter
		// than the old one. if errors ever happen here, the issue is most
		// likely a bug in the construction of the `cached` data structure
		// somewhere earlier in the program
		forEach(cached.nodes, function (node, i) {
			if (node.parentNode != null && nodes.indexOf(node) < 0) {
				clear([node], [cached[i]])
			}
		})

		if (data.length < cached.length) cached.length = data.length
		cached.nodes = nodes
	}

	function buildArrayKeys(data) {
		var guid = 0
		forKeys(data, function () {
			forEach(data, function (attrs) {
				if ((attrs = attrs && attrs.attrs) && attrs.key == null) {
					attrs.key = "__mithril__" + guid++
				}
			})
			return 1
		})
	}

	function isDifferentEnough(data, cached, dataAttrKeys) {
		if (data.tag !== cached.tag) return true

		if (dataAttrKeys.sort().join() !==
				Object.keys(cached.attrs).sort().join()) {
			return true
		}

		if (data.attrs.id !== cached.attrs.id) {
			return true
		}

		if (data.attrs.key !== cached.attrs.key) {
			return true
		}

		if (m.redraw.strategy() === "all") {
			return !cached.configContext || cached.configContext.retain !== true
		}

		if (m.redraw.strategy() === "diff") {
			return cached.configContext && cached.configContext.retain === false
		}

		return false
	}

	function maybeRecreateObject(data, cached, dataAttrKeys) {
		// if an element is different enough from the one in cache, recreate it
		if (isDifferentEnough(data, cached, dataAttrKeys)) {
			if (cached.nodes.length) clear(cached.nodes)

			if (cached.configContext &&
					isFunction(cached.configContext.onunload)) {
				cached.configContext.onunload()
			}

			if (cached.controllers) {
				forEach(cached.controllers, function (controller) {
					if (controller.onunload) {
						controller.onunload({preventDefault: noop})
					}
				})
			}
		}
	}

	function getObjectNamespace(data, namespace) {
		if (data.attrs.xmlns) return data.attrs.xmlns
		if (data.tag === "svg") return "http://www.w3.org/2000/svg"
		if (data.tag === "math") return "http://www.w3.org/1998/Math/MathML"
		return namespace
	}

	var pendingRequests = 0
	m.startComputation = function () { pendingRequests++ }
	m.endComputation = function () {
		if (pendingRequests > 1) {
			pendingRequests--
		} else {
			pendingRequests = 0
			m.redraw()
		}
	}

	function unloadCachedControllers(cached, views, controllers) {
		if (controllers.length) {
			cached.views = views
			cached.controllers = controllers
			forEach(controllers, function (controller) {
				if (controller.onunload && controller.onunload.$old) {
					controller.onunload = controller.onunload.$old
				}

				if (pendingRequests && controller.onunload) {
					var onunload = controller.onunload
					controller.onunload = noop
					controller.onunload.$old = onunload
				}
			})
		}
	}

	function scheduleConfigsToBeCalled(configs, data, node, isNew, cached) {
		// schedule configs to be called. They are called after `build` finishes
		// running
		if (isFunction(data.attrs.config)) {
			var context = cached.configContext = cached.configContext || {}

			// bind
			configs.push(function () {
				return data.attrs.config.call(data, node, !isNew, context,
					cached)
			})
		}
	}

	function buildUpdatedNode(
		cached,
		data,
		editable,
		hasKeys,
		namespace,
		views,
		configs,
		controllers
	) {
		var node = cached.nodes[0]

		if (hasKeys) {
			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 (controllers.length) {
			cached.views = views
			cached.controllers = controllers
		}

		return node
	}

	function handleNonexistentNodes(data, parentElement, index) {
		var nodes
		if (data.$trusted) {
			nodes = injectHTML(parentElement, index, data)
		} else {
			nodes = [$document.createTextNode(data)]
			if (!(parentElement.nodeName in voidElements)) {
				insertNode(parentElement, nodes[0], index)
			}
		}

		var cached

		if (typeof data === "string" ||
				typeof data === "number" ||
				typeof data === "boolean") {
			cached = new data.constructor(data)
		} else {
			cached = data
		}

		cached.nodes = nodes
		return cached
	}

	function reattachNodes(
		data,
		cached,
		parentElement,
		editable,
		index,
		parentTag
	) {
		var nodes = cached.nodes
		if (!editable || editable !== $document.activeElement) {
			if (data.$trusted) {
				clear(nodes, cached)
				nodes = injectHTML(parentElement, index, data)
			} else if (parentTag === "textarea") {
				// <textarea> uses `value` instead of `nodeValue`.
				parentElement.value = data
			} else if (editable) {
				// contenteditable nodes use `innerHTML` instead of `nodeValue`.
				editable.innerHTML = data
			} else {
				// was a trusted string
				if (nodes[0].nodeType === 1 || nodes.length > 1 ||
						(nodes[0].nodeValue.trim &&
							!nodes[0].nodeValue.trim())) {
					clear(cached.nodes, cached)
					nodes = [$document.createTextNode(data)]
				}

				injectTextNode(parentElement, nodes[0], index, data)
			}
		}
		cached = new data.constructor(data)
		cached.nodes = nodes
		return cached
	}

	function handleTextNode(
		cached,
		data,
		index,
		parentElement,
		shouldReattach,
		editable,
		parentTag
	) {
		if (!cached.nodes.length) {
			return handleNonexistentNodes(data, parentElement, index)
		} else if (cached.valueOf() !== data.valueOf() || shouldReattach) {
			return reattachNodes(data, cached, parentElement, editable, index,
				parentTag)
		} else {
			return (cached.nodes.intact = true, cached)
		}
	}

	function getSubArrayCount(item) {
		if (item.$trusted) {
			// fix offset of next element if item was a trusted string w/ more
			// than one html element
			// the first clause in the regexp matches elements
			// the second clause (after the pipe) matches text nodes
			var match = item.match(/<[^\/]|\>\s*[^<]/g)
			if (match != null) return match.length
		} else if (isArray(item)) {
			return item.length
		}
		return 1
	}

	function buildArray(
		data,
		cached,
		parentElement,
		index,
		parentTag,
		shouldReattach,
		editable,
		namespace,
		configs
	) {
		data = flatten(data)
		var nodes = []
		var intact = cached.length === data.length
		var subArrayCount = 0

		// keys algorithm: sort elements without recreating them if keys are
		// present
		//
		// 1) create a map of all existing keys, and mark all for deletion
		// 2) add new keys to map and mark them for addition
		// 3) if key exists in new list, change action from deletion to a move
		// 4) for each key, handle its corresponding action as marked in
		//    previous steps

		var existing = {}
		var shouldMaintainIdentities = false

		forKeys(cached, function (attrs, i) {
			shouldMaintainIdentities = true
			existing[cached[i].attrs.key] = {action: DELETION, index: i}
		})

		buildArrayKeys(data)
		if (shouldMaintainIdentities) {
			cached = diffKeys(data, cached, existing, parentElement)
		}
		// end key algorithm

		var cacheCount = 0
		// faster explicitly written
		for (var i = 0, len = data.length; i < len; i++) {
			// diff each item in the array
			var item = build(
				parentElement,
				parentTag,
				cached,
				index,
				data[i],
				cached[cacheCount],
				shouldReattach,
				index + subArrayCount || subArrayCount,
				editable,
				namespace,
				configs)

			if (item !== undefined) {
				intact = intact && item.nodes.intact
				subArrayCount += getSubArrayCount(item)
				cached[cacheCount++] = item
			}
		}

		if (!intact) diffArray(data, cached, nodes)
		return cached
	}

	function makeCache(data, cached, index, parentIndex, parentCache) {
		if (cached != null) {
			if (type.call(cached) === type.call(data)) return cached

			if (parentCache && parentCache.nodes) {
				var offset = index - parentIndex
				var end = offset + (isArray(data) ? data : cached.nodes).length
				clear(
					parentCache.nodes.slice(offset, end),
					parentCache.slice(offset, end))
			} else if (cached.nodes) {
				clear(cached.nodes, cached)
			}
		}

		cached = new data.constructor()
		// if constructor creates a virtual dom element, use a blank object as
		// the base cached node instead of copying the virtual el (#277)
		if (cached.tag) cached = {}
		cached.nodes = []
		return cached
	}

	function constructNode(data, namespace) {
		if (data.attrs.is) {
			if (namespace == null) {
				return $document.createElement(data.tag, data.attrs.is)
			} else {
				return $document.createElementNS(namespace, data.tag,
					data.attrs.is)
			}
		} else if (namespace == null) {
			return $document.createElement(data.tag)
		} else {
			return $document.createElementNS(namespace, data.tag)
		}
	}

	function constructAttrs(data, node, namespace, hasKeys) {
		if (hasKeys) {
			return setAttributes(node, data.tag, data.attrs, {}, namespace)
		} else {
			return data.attrs
		}
	}

	function constructChildren(
		data,
		node,
		cached,
		editable,
		namespace,
		configs
	) {
		if (data.children != null && data.children.length > 0) {
			return build(
				node,
				data.tag,
				undefined,
				undefined,
				data.children,
				cached.children,
				true,
				0,
				data.attrs.contenteditable ? node : editable,
				namespace,
				configs)
		} else {
			return data.children
		}
	}

	function reconstructCached(
		data,
		attrs,
		children,
		node,
		namespace,
		views,
		controllers
	) {
		var cached = {
			tag: data.tag,
			attrs: attrs,
			children: children,
			nodes: [node]
		}

		unloadCachedControllers(cached, views, controllers)

		if (cached.children && !cached.children.nodes) {
			cached.children.nodes = []
		}

		return cached
	}

	function getController(views, view, cachedControllers, controller) {
		var controllerIndex

		if (m.redraw.strategy() === "diff" && views) {
			controllerIndex = views.indexOf(view)
		} else {
			controllerIndex = -1
		}

		if (controllerIndex > -1) {
			return cachedControllers[controllerIndex]
		} else if (isFunction(controller)) {
			return new controller()
		} else {
			return {}
		}
	}

	var unloaders = []

	function updateLists(views, controllers, view, controller) {
		if (controller.onunload != null &&
				unloaders.map(function (u) { return u.handler })
					.indexOf(controller.onunload) < 0) {
			unloaders.push({
				controller: controller,
				handler: controller.onunload
			})
		}

		views.push(view)
		controllers.push(controller)
	}

	var forcing = false
	function checkView(
		data,
		view,
		cached,
		cachedControllers,
		controllers,
		views
	) {
		var controller = getController(
			cached.views,
			view,
			cachedControllers,
			data.controller)

		var key = data && data.attrs && data.attrs.key

		if (pendingRequests === 0 ||
				forcing ||
				cachedControllers &&
					cachedControllers.indexOf(controller) > -1) {
			data = data.view(controller)
		} else {
			data = {tag: "placeholder"}
		}

		if (data.subtree === "retain") return data
		data.attrs = data.attrs || {}
		data.attrs.key = key
		updateLists(views, controllers, view, controller)
		return data
	}

	function markViews(data, cached, views, controllers) {
		var cachedControllers = cached && cached.controllers

		while (data.view != null) {
			data = checkView(
				data,
				data.view.$original || data.view,
				cached,
				cachedControllers,
				controllers,
				views)
		}

		return data
	}

	function buildObject( // eslint-disable-line max-statements
		data,
		cached,
		editable,
		parentElement,
		index,
		shouldReattach,
		namespace,
		configs
	) {
		var views = []
		var controllers = []

		data = markViews(data, cached, views, controllers)

		if (data.subtree === "retain") return cached

		if (!data.tag && controllers.length) {
			throw new Error("Component template must return a virtual " +
				"element, not an array, string, etc.")
		}

		data.attrs = data.attrs || {}
		cached.attrs = cached.attrs || {}

		var dataAttrKeys = Object.keys(data.attrs)
		var hasKeys = dataAttrKeys.length > ("key" in data.attrs ? 1 : 0)

		maybeRecreateObject(data, cached, dataAttrKeys)

		if (!isString(data.tag)) return

		var isNew = cached.nodes.length === 0

		namespace = getObjectNamespace(data, namespace)

		var node
		if (isNew) {
			node = constructNode(data, namespace)
			// set attributes first, then create children
			var attrs = constructAttrs(data, node, namespace, hasKeys)

			// add the node to its parent before attaching children to it
			insertNode(parentElement, node, index)

			var children = constructChildren(data, node, cached, editable,
				namespace, configs)

			cached = reconstructCached(
				data,
				attrs,
				children,
				node,
				namespace,
				views,
				controllers)
		} else {
			node = buildUpdatedNode(
				cached,
				data,
				editable,
				hasKeys,
				namespace,
				views,
				configs,
				controllers)
		}

		// edge case: setting value on <select> doesn't work before children
		// exist, so set it again after children have been created/updated
		if (data.tag === "select" && "value" in data.attrs) {
			setAttributes(node, data.tag, {value: data.attrs.value}, {},
				namespace)
		}

		if (!isNew && shouldReattach === true && node != null) {
			insertNode(parentElement, node, index)
		}

		// The configs are called after `build` finishes running
		scheduleConfigsToBeCalled(configs, data, node, isNew, cached)

		return cached
	}

	function build(
		parentElement,
		parentTag,
		parentCache,
		parentIndex,
		data,
		cached,
		shouldReattach,
		index,
		editable,
		namespace,
		configs
	) {
		/*
		 * `build` is a recursive function that manages creation/diffing/removal
		 * of DOM elements based on comparison between `data` and `cached` the
		 * diff algorithm can be summarized as this:
		 *
		 * 1 - compare `data` and `cached`
		 * 2 - if they are different, copy `data` to `cached` and update the DOM
		 *     based on what the difference is
		 * 3 - recursively apply this algorithm for every array and for the
		 *     children of every virtual element
		 *
		 * The `cached` data structure is essentially the same as the previous
		 * redraw's `data` data structure, with a few additions:
		 * - `cached` always has a property called `nodes`, which is a list of
		 *    DOM elements that correspond to the data represented by the
		 *    respective virtual element
		 * - in order to support attaching `nodes` as a property of `cached`,
		 *    `cached` is *always* a non-primitive object, i.e. if the data was
		 *    a string, then cached is a String instance. If data was `null` or
		 *    `undefined`, cached is `new String("")`
		 * - `cached also has a `configContext` property, which is the state
		 *    storage object exposed by config(element, isInitialized, context)
		 * - when `cached` is an Object, it represents a virtual element; when
		 *    it's an Array, it represents a list of elements; when it's a
		 *    String, Number or Boolean, it represents a text node
		 *
		 * `parentElement` is a DOM element used for W3C DOM API calls
		 * `parentTag` is only used for handling a corner case for textarea
		 * values
		 * `parentCache` is used to remove nodes in some multi-node cases
		 * `parentIndex` and `index` are used to figure out the offset of nodes.
		 * They're artifacts from before arrays started being flattened and are
		 * likely refactorable
		 * `data` and `cached` are, respectively, the new and old nodes being
		 * diffed
		 * `shouldReattach` is a flag indicating whether a parent node was
		 * recreated (if so, and if this node is reused, then this node must
		 * reattach itself to the new parent)
		 * `editable` is a flag that indicates whether an ancestor is
		 * contenteditable
		 * `namespace` indicates the closest HTML namespace as it cascades down
		 * from an ancestor
		 * `configs` is a list of config functions to run after the topmost
		 * `build` call finishes running
		 *
		 * there's logic that relies on the assumption that null and undefined
		 * data are equivalent to empty strings
		 * - this prevents lifecycle surprises from procedural helpers that mix
		 *   implicit and explicit return statements (e.g.
		 *   function foo() {if (cond) return m("div")}
		 * - it simplifies diffing code
		 */
		data = dataToString(data)
		if (data.subtree === "retain") return cached
		cached = makeCache(data, cached, index, parentIndex, parentCache)

		if (isArray(data)) {
			return buildArray(
				data,
				cached,
				parentElement,
				index,
				parentTag,
				shouldReattach,
				editable,
				namespace,
				configs)
		} else if (data != null && isObject(data)) {
			return buildObject(
				data,
				cached,
				editable,
				parentElement,
				index,
				shouldReattach,
				namespace,
				configs)
		} else if (!isFunction(data)) {
			return handleTextNode(
				cached,
				data,
				index,
				parentElement,
				shouldReattach,
				editable,
				parentTag)
		} else {
			return cached
		}
	}

	function sortChanges(a, b) {
		return a.action - b.action || a.index - b.index
	}

	function copyStyleAttrs(node, dataAttr, cachedAttr) {
		if (cachedAttr === dataAttr) {
			node.style = ""
			cachedAttr = {}
		}
		for (var rule in dataAttr) {
			if (hasOwn.call(dataAttr, rule)) {
				if (cachedAttr == null || cachedAttr[rule] !== dataAttr[rule]) {
					node.style[rule] = dataAttr[rule]
				}
			}
		}

		for (rule in cachedAttr) {
			if (hasOwn.call(cachedAttr, rule)) {
				if (!hasOwn.call(dataAttr, rule)) node.style[rule] = ""
			}
		}
	}

	var shouldUseSetAttribute = {
		list: 1,
		style: 1,
		form: 1,
		type: 1,
		width: 1,
		height: 1
	}

	function setSingleAttr(
		node,
		attrName,
		dataAttr,
		cachedAttr,
		tag,
		namespace
	) {
		if (attrName === "config" || attrName === "key") {
			// `config` isn't a real attribute, so ignore it
			return true
		} else if (isFunction(dataAttr) && attrName.slice(0, 2) === "on") {
			// hook event handlers to the auto-redrawing system
			node[attrName] = autoredraw(dataAttr, node)
		} else if (attrName === "style" && dataAttr != null &&
				isObject(dataAttr)) {
			// handle `style: {...}`
			copyStyleAttrs(node, dataAttr, cachedAttr)
		} else if (namespace != null) {
			// handle SVG
			if (attrName === "href") {
				node.setAttributeNS("http://www.w3.org/1999/xlink",
					"href", dataAttr)
			} else {
				node.setAttribute(
					attrName === "className" ? "class" : attrName,
					dataAttr)
			}
		} else if (attrName in node && !shouldUseSetAttribute[attrName]) {
			// handle cases that are properties (but ignore cases where we
			// should use setAttribute instead)
			//
			// - list and form are typically used as strings, but are DOM
			//   element references in js
			//
			// - when using CSS selectors (e.g. `m("[style='']")`), style is
			//   used as a string, but it's an object in js
			//
			// #348 don't set the value if not needed - otherwise, cursor
			// placement breaks in Chrome
			try {
				if (tag !== "input" || node[attrName] !== dataAttr) {
					node[attrName] = dataAttr
				}
			} catch (e) {
				node.setAttribute(attrName, dataAttr)
			}
		} else node.setAttribute(attrName, dataAttr)
	}

	function trySetAttr(
		node,
		attrName,
		dataAttr,
		cachedAttr,
		cachedAttrs,
		tag,
		namespace
	) {
		if (!(attrName in cachedAttrs) ||
				(cachedAttr !== dataAttr) ||
				typeof dataAttr === "object" ||
				($document.activeElement === node)) {
			cachedAttrs[attrName] = dataAttr
			try {
				return setSingleAttr(
					node,
					attrName,
					dataAttr,
					cachedAttr,
					tag,
					namespace)
			} catch (e) {
				// swallow IE's invalid argument errors to mimic HTML's
				// fallback-to-doing-nothing-on-invalid-attributes behavior
				if (e.message.indexOf("Invalid argument") < 0) throw e
			}
		} else if (attrName === "value" && tag === "input" &&
								node.value !== dataAttr) {
			// #348 dataAttr may not be a string, so use loose comparison
			node.value = dataAttr
		}
	}

	function setAttributes(node, tag, dataAttrs, cachedAttrs, namespace) {
		for (var attrName in dataAttrs) {
			if (hasOwn.call(dataAttrs, attrName)) {
				if (trySetAttr(
						node,
						attrName,
						dataAttrs[attrName],
						cachedAttrs[attrName],
						cachedAttrs,
						tag,
						namespace)) {
					continue
				}
			}
		}
		return cachedAttrs
	}

	function clear(nodes, cached) {
		for (var i = nodes.length - 1; i > -1; i--) {
			if (nodes[i] && nodes[i].parentNode) {
				try {
					nodes[i].parentNode.removeChild(nodes[i])
				} catch (e) {
					/* eslint-disable max-len */
					// ignore if this fails due to order of events (see
					// http://stackoverflow.com/questions/21926083/failed-to-execute-removechild-on-node)
					/* eslint-enable max-len */
				}
				cached = [].concat(cached)
				if (cached[i]) unload(cached[i])
			}
		}
		// release memory if nodes is an array. This check should fail if nodes
		// is a NodeList (see loop above)
		if (nodes.length) {
			nodes.length = 0
		}
	}

	function unload(cached) {
		if (cached.configContext && isFunction(cached.configContext.onunload)) {
			cached.configContext.onunload()
			cached.configContext.onunload = null
		}
		if (cached.controllers) {
			forEach(cached.controllers, function (controller) {
				if (isFunction(controller.onunload)) {
					controller.onunload({preventDefault: noop})
				}
			})
		}
		if (cached.children) {
			if (isArray(cached.children)) forEach(cached.children, unload)
			else if (cached.children.tag) unload(cached.children)
		}
	}

	function appendTextFragment(parentElement, data) {
		try {
			parentElement.appendChild(
				$document.createRange().createContextualFragment(data))
		} catch (e) {
			parentElement.insertAdjacentHTML("beforeend", data)
			replaceScriptNodes(parentElement)
		}
	}

	// Replace script tags inside given DOM element with executable ones.
	// Will also check children recursively and replace any found script
	// tags in same manner.
	function replaceScriptNodes(node) {
		if (node.tagName === "SCRIPT") {
			node.parentNode.replaceChild(buildExecutableNode(node), node)
		} else {
			var children = node.childNodes
			if (children && children.length) {
				for (var i = 0; i < children.length; i++) {
					replaceScriptNodes(children[i])
				}
			}
		}

		return node
	}

	// Replace script element with one whose contents are executable.
	function buildExecutableNode(node){
		var scriptEl = document.createElement("script")
		var attrs = node.attributes

		for (var i = 0; i < attrs.length; i++) {
			scriptEl.setAttribute(attrs[i].name, attrs[i].value)
		}

		scriptEl.text = node.innerHTML
		return scriptEl
	}

	function injectHTML(parentElement, index, data) {
		var nextSibling = parentElement.childNodes[index]
		if (nextSibling) {
			var isElement = nextSibling.nodeType !== 1
			var placeholder = $document.createElement("span")
			if (isElement) {
				parentElement.insertBefore(placeholder, nextSibling || null)
				placeholder.insertAdjacentHTML("beforebegin", data)
				parentElement.removeChild(placeholder)
			} else {
				nextSibling.insertAdjacentHTML("beforebegin", data)
			}
		} else {
			appendTextFragment(parentElement, data)
		}

		var nodes = []

		while (parentElement.childNodes[index] !== nextSibling) {
			nodes.push(parentElement.childNodes[index])
			index++
		}

		return nodes
	}

	function autoredraw(callback, object) {
		return function (e) {
			e = e || event
			m.redraw.strategy("diff")
			m.startComputation()
			try {
				return callback.call(object, e)
			} finally {
				endFirstComputation()
			}
		}
	}

	var html
	var documentNode = {
		appendChild: function (node) {
			if (html === undefined) html = $document.createElement("html")
			if ($document.documentElement &&
					$document.documentElement !== node) {
				$document.replaceChild(node, $document.documentElement)
			} else {
				$document.appendChild(node)
			}

			this.childNodes = $document.childNodes
		},

		insertBefore: function (node) {
			this.appendChild(node)
		},

		childNodes: []
	}

	var nodeCache = []
	var cellCache = {}

	m.render = function (root, cell, forceRecreation) {
		if (!root) {
			throw new Error("Ensure the DOM element being passed to " +
				"m.mount/m.render is not undefined.")
		}
		var configs = []
		var id = getCellCacheKey(root)
		var isDocumentRoot = root === $document
		var node

		if (isDocumentRoot || root === $document.documentElement) {
			node = documentNode
		} else {
			node = root
		}

		if (isDocumentRoot && cell.tag !== "html") {
			cell = {tag: "html", attrs: {}, children: cell}
		}

		if (cellCache[id] === undefined) clear(node.childNodes)
		if (forceRecreation === true) reset(root)

		cellCache[id] = build(
			node,
			null,
			undefined,
			undefined,
			cell,
			cellCache[id],
			false,
			0,
			null,
			undefined,
			configs)

		forEach(configs, function (config) { config() })
	}

	function getCellCacheKey(element) {
		var index = nodeCache.indexOf(element)
		return index < 0 ? nodeCache.push(element) - 1 : index
	}

	m.trust = function (value) {
		value = new String(value) // eslint-disable-line no-new-wrappers
		value.$trusted = true
		return value
	}

	function gettersetter(store) {
		function prop() {
			if (arguments.length) store = arguments[0]
			return store
		}

		prop.toJSON = function () {
			return store
		}

		return prop
	}

	m.prop = function (store) {
		if ((store != null && (isObject(store) || isFunction(store)) ||
					((typeof Promise !== "undefined") &&
						(store instanceof Promise))) &&
				isFunction(store.then)) {
			return propify(store)
		}

		return gettersetter(store)
	}

	var roots = []
	var components = []
	var controllers = []
	var lastRedrawId = null
	var lastRedrawCallTime = 0
	var computePreRedrawHook = null
	var computePostRedrawHook = null
	var topComponent
	var FRAME_BUDGET = 16 // 60 frames per second = 1 call per 16 ms

	function parameterize(component, args) {
		function controller() {
			/* eslint-disable no-invalid-this */
			return (component.controller || noop).apply(this, args) || this
			/* eslint-enable no-invalid-this */
		}

		if (component.controller) {
			controller.prototype = component.controller.prototype
		}

		function view(ctrl) {
			var currentArgs = [ctrl].concat(args)
			for (var i = 1; i < arguments.length; i++) {
				currentArgs.push(arguments[i])
			}

			return component.view.apply(component, currentArgs)
		}

		view.$original = component.view
		var output = {controller: controller, view: view}
		if (args[0] && args[0].key != null) output.attrs = {key: args[0].key}
		return output
	}

	m.component = function (component) {
		var args = new Array(arguments.length - 1)

		for (var i = 1; i < arguments.length; i++) {
			args[i - 1] = arguments[i]
		}

		return parameterize(component, args)
	}

	function checkPrevented(component, root, index, isPrevented) {
		if (!isPrevented) {
			m.redraw.strategy("all")
			m.startComputation()
			roots[index] = root
			var currentComponent

			if (component) {
				currentComponent = topComponent = component
			} else {
				currentComponent = topComponent = component = {controller: noop}
			}

			var controller = new (component.controller || noop)()

			// controllers may call m.mount recursively (via m.route redirects,
			// for example)
			// this conditional ensures only the last recursive m.mount call is
			// applied
			if (currentComponent === topComponent) {
				controllers[index] = controller
				components[index] = component
			}
			endFirstComputation()
			if (component === null) {
				removeRootElement(root, index)
			}
			return controllers[index]
		} else {
			if (component == null) {
				removeRootElement(root, index)
			}
		}
	}

	m.mount = m.module = function (root, component) {
		if (!root) {
			throw new Error("Please ensure the DOM element exists before " +
				"rendering a template into it.")
		}

		var index = roots.indexOf(root)
		if (index < 0) index = roots.length

		var isPrevented = false
		var event = {
			preventDefault: function () {
				isPrevented = true
				computePreRedrawHook = computePostRedrawHook = null
			}
		}

		forEach(unloaders, function (unloader) {
			unloader.handler.call(unloader.controller, event)
			unloader.controller.onunload = null
		})

		if (isPrevented) {
			forEach(unloaders, function (unloader) {
				unloader.controller.onunload = unloader.handler
			})
		} else {
			unloaders = []
		}

		if (controllers[index] && isFunction(controllers[index].onunload)) {
			controllers[index].onunload(event)
		}

		return checkPrevented(component, root, index, isPrevented)
	}

	function removeRootElement(root, index) {
		roots.splice(index, 1)
		controllers.splice(index, 1)
		components.splice(index, 1)
		reset(root)
		nodeCache.splice(getCellCacheKey(root), 1)
		unloaders = []
	}

	var redrawing = false
	m.redraw = function (force) {
		if (redrawing) return
		redrawing = true
		if (force) forcing = true

		try {
			// lastRedrawId is a positive number if a second redraw is requested
			// before the next animation frame
			// lastRedrawId is null if it's the first redraw and not an event
			// handler
			if (lastRedrawId && !force) {
				// when setTimeout: only reschedule redraw if time between now
				// and previous redraw is bigger than a frame, otherwise keep
				// currently scheduled timeout
				// when rAF: always reschedule redraw
				if ($requestAnimationFrame === global.requestAnimationFrame ||
						new Date() - lastRedrawCallTime > FRAME_BUDGET) {
					if (lastRedrawId > 0) $cancelAnimationFrame(lastRedrawId)
					lastRedrawId = $requestAnimationFrame(redraw, FRAME_BUDGET)
				}
			} else {
				redraw()
				lastRedrawId = $requestAnimationFrame(function () {
					lastRedrawId = null
				}, FRAME_BUDGET)
			}
		} finally {
			redrawing = forcing = false
		}
	}

	m.redraw.strategy = m.prop()
	function redraw() {
		if (computePreRedrawHook) {
			computePreRedrawHook()
			computePreRedrawHook = null
		}
		forEach(roots, function (root, i) {
			var component = components[i]
			if (controllers[i]) {
				var args = [controllers[i]]
				m.render(root,
					component.view ? component.view(controllers[i], args) : "")
			}
		})
		// after rendering within a routed context, we need to scroll back to
		// the top, and fetch the document title for history.pushState
		if (computePostRedrawHook) {
			computePostRedrawHook()
			computePostRedrawHook = null
		}
		lastRedrawId = null
		lastRedrawCallTime = new Date()
		m.redraw.strategy("diff")
	}

	function endFirstComputation() {
		if (m.redraw.strategy() === "none") {
			pendingRequests--
			m.redraw.strategy("diff")
		} else {
			m.endComputation()
		}
	}

	m.withAttr = function (prop, withAttrCallback, callbackThis) {
		return function (e) {
			e = e || window.event
			/* eslint-disable no-invalid-this */
			var currentTarget = e.currentTarget || this
			var _this = callbackThis || this
			/* eslint-enable no-invalid-this */
			var target = prop in currentTarget ?
				currentTarget[prop] :
				currentTarget.getAttribute(prop)
			withAttrCallback.call(_this, target)
		}
	}

	// routing

	function reset(root) {
		var cacheKey = getCellCacheKey(root)
		clear(root.childNodes, cellCache[cacheKey])
		cellCache[cacheKey] = undefined
	}

	m.deferred = function () {
		var deferred = new Deferred()
		deferred.promise = propify(deferred.promise)
		return deferred
	}

	function propify(promise, initialValue) {
		var prop = m.prop(initialValue)
		promise.then(prop)
		prop.then = function (resolve, reject) {
			return propify(promise.then(resolve, reject), initialValue)
		}

		prop["catch"] = prop.then.bind(null, null)
		return prop
	}
	// Promiz.mithril.js | Zolmeister | MIT
	// a modified version of Promiz.js, which does not conform to Promises/A+
	// for two reasons:
	//
	// 1) `then` callbacks are called synchronously (because setTimeout is too
	//    slow, and the setImmediate polyfill is too big
	//
	// 2) throwing subclasses of Error cause the error to be bubbled up instead
	//    of triggering rejection (because the spec does not account for the
	//    important use case of default browser error handling, i.e. message w/
	//    line number)

	var RESOLVING = 1
	var REJECTING = 2
	var RESOLVED = 3
	var REJECTED = 4

	function Deferred(onSuccess, onFailure) {
		var self = this
		var state = 0
		var promiseValue = 0
		var next = []

		self.promise = {}

		self.resolve = function (value) {
			if (!state) {
				promiseValue = value
				state = RESOLVING

				fire()
			}

			return self
		}

		self.reject = function (value) {
			if (!state) {
				promiseValue = value
				state = REJECTING

				fire()
			}

			return self
		}

		self.promise.then = function (onSuccess, onFailure) {
			var deferred = new Deferred(onSuccess, onFailure)

			if (state === RESOLVED) {
				deferred.resolve(promiseValue)
			} else if (state === REJECTED) {
				deferred.reject(promiseValue)
			} else {
				next.push(deferred)
			}

			return deferred.promise
		}

		function finish(type) {
			state = type || REJECTED
			next.map(function (deferred) {
				if (state === RESOLVED) {
					deferred.resolve(promiseValue)
				} else {
					deferred.reject(promiseValue)
				}
			})
		}

		function thennable(then, success, failure, notThennable) {
			if (((promiseValue != null && isObject(promiseValue)) ||
					isFunction(promiseValue)) && isFunction(then)) {
				try {
					// count protects against abuse calls from spec checker
					var count = 0
					then.call(promiseValue, function (value) {
						if (count++) return
						promiseValue = value
						success()
					}, function (value) {
						if (count++) return
						promiseValue = value
						failure()
					})
				} catch (e) {
					m.deferred.onerror(e)
					promiseValue = e
					failure()
				}
			} else {
				notThennable()
			}
		}

		function fire() {
			// check if it's a thenable
			var then
			try {
				then = promiseValue && promiseValue.then
			} catch (e) {
				m.deferred.onerror(e)
				promiseValue = e
				state = REJECTING
				return fire()
			}

			if (state === REJECTING) {
				m.deferred.onerror(promiseValue)
			}

			thennable(then, function () {
				state = RESOLVING
				fire()
			}, function () {
				state = REJECTING
				fire()
			}, function () {
				try {
					if (state === RESOLVING && isFunction(onSuccess)) {
						promiseValue = onSuccess(promiseValue)
					} else if (state === REJECTING && isFunction(onFailure)) {
						promiseValue = onFailure(promiseValue)
						state = RESOLVING
					}
				} catch (e) {
					m.deferred.onerror(e)
					promiseValue = e
					return finish()
				}

				if (promiseValue === self) {
					promiseValue = TypeError()
					finish()
				} else {
					thennable(then, function () {
						finish(RESOLVED)
					}, finish, function () {
						finish(state === RESOLVING && RESOLVED)
					})
				}
			})
		}
	}

	m.deferred.onerror = function (e) {
		if (type.call(e) === "[object Error]" &&
				!/ Error/.test(e.constructor.toString())) {
			pendingRequests = 0
			throw e
		}
	}

	m.sync = function (args) {
		var deferred = m.deferred()
		var outstanding = args.length
		var results = []
		var method = "resolve"

		function synchronizer(pos, resolved) {
			return function (value) {
				results[pos] = value
				if (!resolved) method = "reject"
				if (--outstanding === 0) {
					deferred.promise(results)
					deferred[method](results)
				}
				return value
			}
		}

		if (args.length > 0) {
			forEach(args, function (arg, i) {
				arg.then(synchronizer(i, true), synchronizer(i, false))
			})
		} else {
			deferred.resolve([])
		}

		return deferred.promise
	}


	return m
});