diff --git a/api/router.js b/api/router.js
index 496b5684..2ca45757 100644
--- a/api/router.js
+++ b/api/router.js
@@ -11,13 +11,13 @@ module.exports = function($window, renderer, pubsub) {
 		var replay = router.defineRoutes(routes, function(payload, args, path, route) {
 			if (typeof payload.view !== "function") {
 				if (typeof payload.render !== "function") payload.render = function(vnode) {return vnode}
-				var render = function(component) {
+				var use = function(component) {
 					current.path = path, current.component = component
 					renderer.render(root, payload.render(Vnode(component, null, args, undefined, undefined, undefined)))
 				}
-				if (typeof payload.resolve !== "function") payload.resolve = function() {render(current.component)}
-				if (path !== current.path) payload.resolve(render, args, path, route)
-				else render(current.component)
+				if (typeof payload.resolve !== "function") payload.resolve = function() {use(current.component)}
+				if (path !== current.path) payload.resolve(use, args, path, route)
+				else use(current.component)
 			}
 			else {
 				renderer.render(root, Vnode(payload, null, args, undefined, undefined, undefined))
diff --git a/index.js b/index.js
index 710df2fb..2c63a54f 100644
--- a/index.js
+++ b/index.js
@@ -1,6 +1,6 @@
 "use strict"
 
-var Stream = require("./util/stream")
+var Stream = require("./util/stream")(console.error.bind(console))
 var m = require("./render/hyperscript")
 var renderService = require("./render/render")(window)
 var requestService = require("./request/request")(window)
diff --git a/mithril.js b/mithril.js
index e279e368..930a359b 100644
--- a/mithril.js
+++ b/mithril.js
@@ -1,186 +1,188 @@
 new function() {
-var guid = 0, noop = function() {}, HALT = {}
-function createStream() {
-	function stream() {
-		if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, arguments[0], undefined)
-		return stream._state.value
-	}
-	initStream(stream, arguments)
-	if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, arguments[0], undefined)
-	return stream
-}
-function initStream(stream, args) {
-	stream.constructor = createStream
-	stream._state = {id: guid++, value: undefined, error: undefined, state: 0, derive: undefined, recover: undefined, deps: {}, parents: [], errorStream: undefined, endStream: undefined}
-	stream.map = map, stream.ap = ap, stream.of = createStream
-	stream.valueOf = valueOf, stream.toJSON = toJSON, stream.toString = valueOf
-	stream.run = run, stream.catch = doCatch
-	Object.defineProperties(stream, {
-		error: {get: function() {
-			if (!stream._state.errorStream) {
-				var errorStream = function() {
-					if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, undefined, arguments[0])
-					return stream._state.error
-				}
-				initStream(errorStream, [])
-				initDependency(errorStream, [stream], noop, noop)
-				stream._state.errorStream = errorStream
-			}
-			return stream._state.errorStream
-		}},
-		end: {get: function() {
-			if (!stream._state.endStream) {
-				var endStream = createStream()
-				endStream.map(function(value) {
-					if (value === true) unregisterStream(stream), unregisterStream(endStream)
-					return value
-				})
-				stream._state.endStream = endStream
-			}
-			return stream._state.endStream
-		}}
-	})
-}
-function updateStream(stream, value, error) {
-	updateState(stream, value, error)
-	for (var id in stream._state.deps) updateDependency(stream._state.deps[id], false)
-	finalize(stream)
-}
-function updateState(stream, value, error) {
-	error = unwrapError(value, error)
-	if (error !== undefined && typeof stream._state.recover === "function") {
-		if (!resolve(stream, updateValues, true)) return
-	}
-	else updateValues(stream, value, error)
-	stream._state.changed = true
-	if (stream._state.state !== 2) stream._state.state = 1
-}
-function updateValues(stream, value, error) {
-	stream._state.value = value
-	stream._state.error = error
-}
-function updateDependency(stream, mustSync) {
-	var state = stream._state, parents = state.parents
-	if (parents.length > 0 && parents.filter(active).length === parents.length && (mustSync || parents.filter(changed).length > 0)) {
-		var failed = parents.filter(errored)
-		if (failed.length > 0) updateState(stream, undefined, failed[0]._state.error)
-		else resolve(stream, updateState, false)
-	}
-}
-function resolve(stream, update, shouldRecover) {
-	try {
-		var value = shouldRecover ? stream._state.recover() : stream._state.derive()
-		if (value === HALT) return false
-		update(stream, value, undefined)
-	}
-	catch (e) {
-		update(stream, undefined, e)
-		reportUncaughtError(stream, e)
-	}
-	return true
-}
-function unwrapError(value, error) {
-	if (value != null && value.constructor === createStream) {
-		if (value._state.error !== undefined) error = value._state.error
-		else error = unwrapError(value._state.value, value._state.error)
-	}
-	return error
-}
-function finalize(stream) {
-	stream._state.changed = false
-	for (var id in stream._state.deps) stream._state.deps[id]._state.changed = false
-}
-function reportUncaughtError(stream, e) {
-	if (Object.keys(stream._state.deps).length === 0 && stream._state.derive == null) {
-		setTimeout(function() {
-			if (Object.keys(stream._state.deps).length === 0) console.error(e)
-		}, 0)
-	}
-}
-function run(fn) {
-	var self = createStream(), stream = this
-	return initDependency(self, [stream], function() {
-		return absorb(self, fn(stream()))
-	}, undefined)
-}
-function doCatch(fn) {
-	var self = createStream(), stream = this
-	var derive = function() {return stream._state.value}
-	var recover = function() {return absorb(self, fn(stream._state.error))}
-	return initDependency(self, [stream], derive, recover)
-}
-function combine(fn, streams) {
-	return initDependency(createStream(), streams, function() {
-		var failed = streams.filter(errored)
-		if (failed.length > 0) throw failed[0]._state.error
-		return fn.apply(this, streams.concat([streams.filter(changed)]))
-	}, undefined)
-}
-function absorb(stream, value) {
-	if (value != null && value.constructor === createStream) {
-		var absorbable = value
-		var update = function() {
-			updateState(stream, absorbable._state.value, absorbable._state.error)
-			for (var id in stream._state.deps) updateDependency(stream._state.deps[id], false)
+var Stream = function(log) {
+	var guid = 0, noop = function() {}, HALT = {}
+	function createStream() {
+		function stream() {
+			if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, arguments[0], undefined)
+			return stream._state.value
 		}
-		absorbable.map(update).catch(function(e) {
-			update()
-			throw e
+		initStream(stream, arguments)
+		if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, arguments[0], undefined)
+		return stream
+	}
+	function initStream(stream, args) {
+		stream.constructor = createStream
+		stream._state = {id: guid++, value: undefined, error: undefined, state: 0, derive: undefined, recover: undefined, deps: {}, parents: [], errorStream: undefined, endStream: undefined}
+		stream.map = map, stream.ap = ap, stream.of = createStream
+		stream.valueOf = valueOf, stream.toJSON = toJSON, stream.toString = valueOf
+		stream.run = run, stream.catch = doCatch
+		Object.defineProperties(stream, {
+			error: {get: function() {
+				if (!stream._state.errorStream) {
+					var errorStream = function() {
+						if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, undefined, arguments[0])
+						return stream._state.error
+					}
+					initStream(errorStream, [])
+					initDependency(errorStream, [stream], noop, noop)
+					stream._state.errorStream = errorStream
+				}
+				return stream._state.errorStream
+			}},
+			end: {get: function() {
+				if (!stream._state.endStream) {
+					var endStream = createStream()
+					endStream.map(function(value) {
+						if (value === true) unregisterStream(stream), unregisterStream(endStream)
+						return value
+					})
+					stream._state.endStream = endStream
+				}
+				return stream._state.endStream
+			}}
 		})
-		
-		if (absorbable._state.state === 0) return HALT
-		if (absorbable._state.error) throw absorbable._state.error
-		value = absorbable._state.value
 	}
-	return value
-}
-function initDependency(dep, streams, derive, recover) {
-	var state = dep._state
-	state.derive = derive
-	state.recover = recover
-	state.parents = streams.filter(notEnded)
-	registerDependency(dep, state.parents)
-	updateDependency(dep, true)
-	return dep
-}
-function registerDependency(stream, parents) {
-	for (var i = 0; i < parents.length; i++) {
-		parents[i]._state.deps[stream._state.id] = stream
-		registerDependency(stream, parents[i]._state.parents)
+	function updateStream(stream, value, error) {
+		updateState(stream, value, error)
+		for (var id in stream._state.deps) updateDependency(stream._state.deps[id], false)
+		finalize(stream)
 	}
-}
-function unregisterStream(stream) {
-	for (var i = 0; i < stream._state.parents.length; i++) {
-		var parent = stream._state.parents[i]
-		delete parent._state.deps[stream._state.id]
+	function updateState(stream, value, error) {
+		error = unwrapError(value, error)
+		if (error !== undefined && typeof stream._state.recover === "function") {
+			if (!resolve(stream, updateValues, true)) return
+		}
+		else updateValues(stream, value, error)
+		stream._state.changed = true
+		if (stream._state.state !== 2) stream._state.state = 1
 	}
-	for (var id in stream._state.deps) {
-		var dependent = stream._state.deps[id]
-		var index = dependent._state.parents.indexOf(stream)
-		if (index > -1) dependent._state.parents.splice(index, 1)
+	function updateValues(stream, value, error) {
+		stream._state.value = value
+		stream._state.error = error
 	}
-	stream._state.state = 2 //ended
-	stream._state.deps = {}
-}
-function map(fn) {return combine(function(stream) {return fn(stream())}, [this])}
-function ap(stream) {return combine(function(s1, s2) {return s1()(s2())}, [this, stream])}
-function valueOf() {return this._state.value}
-function toJSON() {return JSON.stringify(this._state.value)}
-function active(stream) {return stream._state.state === 1}
-function changed(stream) {return stream._state.changed}
-function notEnded(stream) {return stream._state.state !== 2}
-function errored(stream) {return stream._state.error}
-function reject(e) {
-	var stream = createStream()
-	stream.error(e)
-	return stream
-}
-function merge(streams) {
-	return combine(function () {
-		return streams.map(function(s) {return s()})
-	}, streams)
-}
-var Stream = {stream: createStream, merge: merge, combine: combine, reject: reject, HALT: HALT}
+	function updateDependency(stream, mustSync) {
+		var state = stream._state, parents = state.parents
+		if (parents.length > 0 && parents.filter(active).length === parents.length && (mustSync || parents.filter(changed).length > 0)) {
+			var failed = parents.filter(errored)
+			if (failed.length > 0) updateState(stream, undefined, failed[0]._state.error)
+			else resolve(stream, updateState, false)
+		}
+	}
+	function resolve(stream, update, shouldRecover) {
+		try {
+			var value = shouldRecover ? stream._state.recover() : stream._state.derive()
+			if (value === HALT) return false
+			update(stream, value, undefined)
+		}
+		catch (e) {
+			update(stream, undefined, e.__error != null ? e.__error : e)
+			if (e.__error == null) reportUncaughtError(stream, e)
+		}
+		return true
+	}
+	function unwrapError(value, error) {
+		if (value != null && value.constructor === createStream) {
+			if (value._state.error !== undefined) error = value._state.error
+			else error = unwrapError(value._state.value, value._state.error)
+		}
+		return error
+	}
+	function finalize(stream) {
+		stream._state.changed = false
+		for (var id in stream._state.deps) stream._state.deps[id]._state.changed = false
+	}
+	function reportUncaughtError(stream, e) {
+		if (Object.keys(stream._state.deps).length === 0) {
+			setTimeout(function() {
+				if (Object.keys(stream._state.deps).length === 0) log(e)
+			}, 0)
+		}
+	}
+	function run(fn) {
+		var self = createStream(), stream = this
+		return initDependency(self, [stream], function() {
+			return absorb(self, fn(stream()))
+		}, undefined)
+	}
+	function doCatch(fn) {
+		var self = createStream(), stream = this
+		var derive = function() {return stream._state.value}
+		var recover = function() {return absorb(self, fn(stream._state.error))}
+		return initDependency(self, [stream], derive, recover)
+	}
+	function combine(fn, streams) {
+		return initDependency(createStream(), streams, function() {
+			var failed = streams.filter(errored)
+			if (failed.length > 0) throw {__error: failed[0]._state.error}
+			return fn.apply(this, streams.concat([streams.filter(changed)]))
+		}, undefined)
+	}
+	function absorb(stream, value) {
+		if (value != null && value.constructor === createStream) {
+			var absorbable = value
+			var update = function() {
+				updateState(stream, absorbable._state.value, absorbable._state.error)
+				for (var id in stream._state.deps) updateDependency(stream._state.deps[id], false)
+			}
+			absorbable.map(update).catch(function(e) {
+				update()
+				throw {__error: e}
+			})
+			
+			if (absorbable._state.state === 0) return HALT
+			if (absorbable._state.error) throw {__error: absorbable._state.error}
+			value = absorbable._state.value
+		}
+		return value
+	}
+	function initDependency(dep, streams, derive, recover) {
+		var state = dep._state
+		state.derive = derive
+		state.recover = recover
+		state.parents = streams.filter(notEnded)
+		registerDependency(dep, state.parents)
+		updateDependency(dep, true)
+		return dep
+	}
+	function registerDependency(stream, parents) {
+		for (var i = 0; i < parents.length; i++) {
+			parents[i]._state.deps[stream._state.id] = stream
+			registerDependency(stream, parents[i]._state.parents)
+		}
+	}
+	function unregisterStream(stream) {
+		for (var i = 0; i < stream._state.parents.length; i++) {
+			var parent = stream._state.parents[i]
+			delete parent._state.deps[stream._state.id]
+		}
+		for (var id in stream._state.deps) {
+			var dependent = stream._state.deps[id]
+			var index = dependent._state.parents.indexOf(stream)
+			if (index > -1) dependent._state.parents.splice(index, 1)
+		}
+		stream._state.state = 2 //ended
+		stream._state.deps = {}
+	}
+	function map(fn) {return combine(function(stream) {return fn(stream())}, [this])}
+	function ap(stream) {return combine(function(s1, s2) {return s1()(s2())}, [this, stream])}
+	function valueOf() {return this._state.value}
+	function toJSON() {return this._state.value != null && typeof this._state.value.toJSON === "function" ? this._state.value.toJSON() : this._state.value}
+	function active(stream) {return stream._state.state === 1}
+	function changed(stream) {return stream._state.changed}
+	function notEnded(stream) {return stream._state.state !== 2}
+	function errored(stream) {return stream._state.error}
+	function reject(e) {
+		var stream = createStream()
+		stream.error(e)
+		return stream
+	}
+	function merge(streams) {
+		return combine(function () {
+			return streams.map(function(s) {return s()})
+		}, streams)
+	}
+	return {stream: createStream, merge: merge, combine: combine, reject: reject, HALT: HALT}
+}(console.error.bind(console))
 function Vnode(tag, key, attrs, children, text, dom) {
 	return {tag: tag, key: key, attrs: attrs, children: children, text: text, dom: dom, domSize: undefined, state: {}, events: undefined, instance: undefined}
 }
@@ -1087,13 +1089,13 @@ m.route = function($window, renderer, pubsub) {
 		var replay = router.defineRoutes(routes, function(payload, args, path, route) {
 			if (typeof payload.view !== "function") {
 				if (typeof payload.render !== "function") payload.render = function(vnode) {return vnode}
-				var render = function(component) {
+				var use = function(component) {
 					current.path = path, current.component = component
 					renderer.render(root, payload.render(Vnode(component, null, args, undefined, undefined, undefined)))
 				}
-				if (typeof payload.resolve !== "function") payload.resolve = function() {render(current.component)}
-				if (path !== current.path) payload.resolve(render, args, path, route)
-				else render(current.component)
+				if (typeof payload.resolve !== "function") payload.resolve = function() {use(current.component)}
+				if (path !== current.path) payload.resolve(use, args, path, route)
+				else use(current.component)
 			}
 			else {
 				renderer.render(root, Vnode(payload, null, args, undefined, undefined, undefined))
diff --git a/util/stream.js b/util/stream.js
index d61df9aa..27640abf 100644
--- a/util/stream.js
+++ b/util/stream.js
@@ -1,196 +1,198 @@
 "use strict"
 
-var guid = 0, noop = function() {}, HALT = {}
-function createStream() {
-	function stream() {
-		if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, arguments[0], undefined)
-		return stream._state.value
-	}
-	initStream(stream, arguments)
-
-	if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, arguments[0], undefined)
-
-	return stream
-}
-function initStream(stream, args) {
-	stream.constructor = createStream
-	stream._state = {id: guid++, value: undefined, error: undefined, state: 0, derive: undefined, recover: undefined, deps: {}, parents: [], errorStream: undefined, endStream: undefined}
-	stream.map = map, stream.ap = ap, stream.of = createStream
-	stream.valueOf = valueOf, stream.toJSON = toJSON, stream.toString = valueOf
-	stream.run = run, stream.catch = doCatch
-
-	Object.defineProperties(stream, {
-		error: {get: function() {
-			if (!stream._state.errorStream) {
-				var errorStream = function() {
-					if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, undefined, arguments[0])
-					return stream._state.error
-				}
-				initStream(errorStream, [])
-				initDependency(errorStream, [stream], noop, noop)
-				stream._state.errorStream = errorStream
-			}
-			return stream._state.errorStream
-		}},
-		end: {get: function() {
-			if (!stream._state.endStream) {
-				var endStream = createStream()
-				endStream.map(function(value) {
-					if (value === true) unregisterStream(stream), unregisterStream(endStream)
-					return value
-				})
-				stream._state.endStream = endStream
-			}
-			return stream._state.endStream
-		}}
-	})
-}
-function updateStream(stream, value, error) {
-	updateState(stream, value, error)
-	for (var id in stream._state.deps) updateDependency(stream._state.deps[id], false)
-	finalize(stream)
-}
-function updateState(stream, value, error) {
-	error = unwrapError(value, error)
-	if (error !== undefined && typeof stream._state.recover === "function") {
-		if (!resolve(stream, updateValues, true)) return
-	}
-	else updateValues(stream, value, error)
-	stream._state.changed = true
-	if (stream._state.state !== 2) stream._state.state = 1
-}
-function updateValues(stream, value, error) {
-	stream._state.value = value
-	stream._state.error = error
-}
-function updateDependency(stream, mustSync) {
-	var state = stream._state, parents = state.parents
-	if (parents.length > 0 && parents.filter(active).length === parents.length && (mustSync || parents.filter(changed).length > 0)) {
-		var failed = parents.filter(errored)
-		if (failed.length > 0) updateState(stream, undefined, failed[0]._state.error)
-		else resolve(stream, updateState, false)
-	}
-}
-function resolve(stream, update, shouldRecover) {
-	try {
-		var value = shouldRecover ? stream._state.recover() : stream._state.derive()
-		if (value === HALT) return false
-		update(stream, value, undefined)
-	}
-	catch (e) {
-		update(stream, undefined, e)
-		reportUncaughtError(stream, e)
-	}
-	return true
-}
-function unwrapError(value, error) {
-	if (value != null && value.constructor === createStream) {
-		if (value._state.error !== undefined) error = value._state.error
-		else error = unwrapError(value._state.value, value._state.error)
-	}
-	return error
-}
-function finalize(stream) {
-	stream._state.changed = false
-	for (var id in stream._state.deps) stream._state.deps[id]._state.changed = false
-}
-function reportUncaughtError(stream, e) {
-	if (Object.keys(stream._state.deps).length === 0 && stream._state.derive == null) {
-		setTimeout(function() {
-			if (Object.keys(stream._state.deps).length === 0) console.error(e)
-		}, 0)
-	}
-}
-
-function run(fn) {
-	var self = createStream(), stream = this
-	return initDependency(self, [stream], function() {
-		return absorb(self, fn(stream()))
-	}, undefined)
-}
-function doCatch(fn) {
-	var self = createStream(), stream = this
-	var derive = function() {return stream._state.value}
-	var recover = function() {return absorb(self, fn(stream._state.error))}
-	return initDependency(self, [stream], derive, recover)
-}
-function combine(fn, streams) {
-	return initDependency(createStream(), streams, function() {
-		var failed = streams.filter(errored)
-		if (failed.length > 0) throw failed[0]._state.error
-		return fn.apply(this, streams.concat([streams.filter(changed)]))
-	}, undefined)
-}
-function absorb(stream, value) {
-	if (value != null && value.constructor === createStream) {
-		var absorbable = value
-		var update = function() {
-			updateState(stream, absorbable._state.value, absorbable._state.error)
-			for (var id in stream._state.deps) updateDependency(stream._state.deps[id], false)
+module.exports = function(log) {
+	var guid = 0, noop = function() {}, HALT = {}
+	function createStream() {
+		function stream() {
+			if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, arguments[0], undefined)
+			return stream._state.value
 		}
-		absorbable.map(update).catch(function(e) {
-			update()
-			throw e
+		initStream(stream, arguments)
+
+		if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, arguments[0], undefined)
+
+		return stream
+	}
+	function initStream(stream, args) {
+		stream.constructor = createStream
+		stream._state = {id: guid++, value: undefined, error: undefined, state: 0, derive: undefined, recover: undefined, deps: {}, parents: [], errorStream: undefined, endStream: undefined}
+		stream.map = map, stream.ap = ap, stream.of = createStream
+		stream.valueOf = valueOf, stream.toJSON = toJSON, stream.toString = valueOf
+		stream.run = run, stream.catch = doCatch
+
+		Object.defineProperties(stream, {
+			error: {get: function() {
+				if (!stream._state.errorStream) {
+					var errorStream = function() {
+						if (arguments.length > 0 && arguments[0] !== HALT) updateStream(stream, undefined, arguments[0])
+						return stream._state.error
+					}
+					initStream(errorStream, [])
+					initDependency(errorStream, [stream], noop, noop)
+					stream._state.errorStream = errorStream
+				}
+				return stream._state.errorStream
+			}},
+			end: {get: function() {
+				if (!stream._state.endStream) {
+					var endStream = createStream()
+					endStream.map(function(value) {
+						if (value === true) unregisterStream(stream), unregisterStream(endStream)
+						return value
+					})
+					stream._state.endStream = endStream
+				}
+				return stream._state.endStream
+			}}
 		})
-		
-		if (absorbable._state.state === 0) return HALT
-		if (absorbable._state.error) throw absorbable._state.error
-		value = absorbable._state.value
 	}
-	return value
-}
-
-function initDependency(dep, streams, derive, recover) {
-	var state = dep._state
-	state.derive = derive
-	state.recover = recover
-	state.parents = streams.filter(notEnded)
-
-	registerDependency(dep, state.parents)
-	updateDependency(dep, true)
-
-	return dep
-}
-function registerDependency(stream, parents) {
-	for (var i = 0; i < parents.length; i++) {
-		parents[i]._state.deps[stream._state.id] = stream
-		registerDependency(stream, parents[i]._state.parents)
+	function updateStream(stream, value, error) {
+		updateState(stream, value, error)
+		for (var id in stream._state.deps) updateDependency(stream._state.deps[id], false)
+		finalize(stream)
 	}
-}
-function unregisterStream(stream) {
-	for (var i = 0; i < stream._state.parents.length; i++) {
-		var parent = stream._state.parents[i]
-		delete parent._state.deps[stream._state.id]
+	function updateState(stream, value, error) {
+		error = unwrapError(value, error)
+		if (error !== undefined && typeof stream._state.recover === "function") {
+			if (!resolve(stream, updateValues, true)) return
+		}
+		else updateValues(stream, value, error)
+		stream._state.changed = true
+		if (stream._state.state !== 2) stream._state.state = 1
 	}
-	for (var id in stream._state.deps) {
-		var dependent = stream._state.deps[id]
-		var index = dependent._state.parents.indexOf(stream)
-		if (index > -1) dependent._state.parents.splice(index, 1)
+	function updateValues(stream, value, error) {
+		stream._state.value = value
+		stream._state.error = error
 	}
-	stream._state.state = 2 //ended
-	stream._state.deps = {}
+	function updateDependency(stream, mustSync) {
+		var state = stream._state, parents = state.parents
+		if (parents.length > 0 && parents.filter(active).length === parents.length && (mustSync || parents.filter(changed).length > 0)) {
+			var failed = parents.filter(errored)
+			if (failed.length > 0) updateState(stream, undefined, failed[0]._state.error)
+			else resolve(stream, updateState, false)
+		}
+	}
+	function resolve(stream, update, shouldRecover) {
+		try {
+			var value = shouldRecover ? stream._state.recover() : stream._state.derive()
+			if (value === HALT) return false
+			update(stream, value, undefined)
+		}
+		catch (e) {
+			update(stream, undefined, e.__error != null ? e.__error : e)
+			if (e.__error == null) reportUncaughtError(stream, e)
+		}
+		return true
+	}
+	function unwrapError(value, error) {
+		if (value != null && value.constructor === createStream) {
+			if (value._state.error !== undefined) error = value._state.error
+			else error = unwrapError(value._state.value, value._state.error)
+		}
+		return error
+	}
+	function finalize(stream) {
+		stream._state.changed = false
+		for (var id in stream._state.deps) stream._state.deps[id]._state.changed = false
+	}
+	function reportUncaughtError(stream, e) {
+		if (Object.keys(stream._state.deps).length === 0) {
+			setTimeout(function() {
+				if (Object.keys(stream._state.deps).length === 0) log(e)
+			}, 0)
+		}
+	}
+
+	function run(fn) {
+		var self = createStream(), stream = this
+		return initDependency(self, [stream], function() {
+			return absorb(self, fn(stream()))
+		}, undefined)
+	}
+	function doCatch(fn) {
+		var self = createStream(), stream = this
+		var derive = function() {return stream._state.value}
+		var recover = function() {return absorb(self, fn(stream._state.error))}
+		return initDependency(self, [stream], derive, recover)
+	}
+	function combine(fn, streams) {
+		return initDependency(createStream(), streams, function() {
+			var failed = streams.filter(errored)
+			if (failed.length > 0) throw {__error: failed[0]._state.error}
+			return fn.apply(this, streams.concat([streams.filter(changed)]))
+		}, undefined)
+	}
+	function absorb(stream, value) {
+		if (value != null && value.constructor === createStream) {
+			var absorbable = value
+			var update = function() {
+				updateState(stream, absorbable._state.value, absorbable._state.error)
+				for (var id in stream._state.deps) updateDependency(stream._state.deps[id], false)
+			}
+			absorbable.map(update).catch(function(e) {
+				update()
+				throw {__error: e}
+			})
+			
+			if (absorbable._state.state === 0) return HALT
+			if (absorbable._state.error) throw {__error: absorbable._state.error}
+			value = absorbable._state.value
+		}
+		return value
+	}
+
+	function initDependency(dep, streams, derive, recover) {
+		var state = dep._state
+		state.derive = derive
+		state.recover = recover
+		state.parents = streams.filter(notEnded)
+
+		registerDependency(dep, state.parents)
+		updateDependency(dep, true)
+
+		return dep
+	}
+	function registerDependency(stream, parents) {
+		for (var i = 0; i < parents.length; i++) {
+			parents[i]._state.deps[stream._state.id] = stream
+			registerDependency(stream, parents[i]._state.parents)
+		}
+	}
+	function unregisterStream(stream) {
+		for (var i = 0; i < stream._state.parents.length; i++) {
+			var parent = stream._state.parents[i]
+			delete parent._state.deps[stream._state.id]
+		}
+		for (var id in stream._state.deps) {
+			var dependent = stream._state.deps[id]
+			var index = dependent._state.parents.indexOf(stream)
+			if (index > -1) dependent._state.parents.splice(index, 1)
+		}
+		stream._state.state = 2 //ended
+		stream._state.deps = {}
+	}
+
+	function map(fn) {return combine(function(stream) {return fn(stream())}, [this])}
+	function ap(stream) {return combine(function(s1, s2) {return s1()(s2())}, [this, stream])}
+	function valueOf() {return this._state.value}
+	function toJSON() {return this._state.value != null && typeof this._state.value.toJSON === "function" ? this._state.value.toJSON() : this._state.value}
+
+	function active(stream) {return stream._state.state === 1}
+	function changed(stream) {return stream._state.changed}
+	function notEnded(stream) {return stream._state.state !== 2}
+	function errored(stream) {return stream._state.error}
+
+	function reject(e) {
+		var stream = createStream()
+		stream.error(e)
+		return stream
+	}
+
+	function merge(streams) {
+		return combine(function () {
+			return streams.map(function(s) {return s()})
+		}, streams)
+	}
+
+	return {stream: createStream, merge: merge, combine: combine, reject: reject, HALT: HALT}
 }
-
-function map(fn) {return combine(function(stream) {return fn(stream())}, [this])}
-function ap(stream) {return combine(function(s1, s2) {return s1()(s2())}, [this, stream])}
-function valueOf() {return this._state.value}
-function toJSON() {return JSON.stringify(this._state.value)}
-
-function active(stream) {return stream._state.state === 1}
-function changed(stream) {return stream._state.changed}
-function notEnded(stream) {return stream._state.state !== 2}
-function errored(stream) {return stream._state.error}
-
-function reject(e) {
-	var stream = createStream()
-	stream.error(e)
-	return stream
-}
-
-function merge(streams) {
-	return combine(function () {
-		return streams.map(function(s) {return s()})
-	}, streams)
-}
-
-module.exports = {stream: createStream, merge: merge, combine: combine, reject: reject, HALT: HALT}
diff --git a/util/tests/test-stream.js b/util/tests/test-stream.js
index e0ca9260..4fec7dcc 100644
--- a/util/tests/test-stream.js
+++ b/util/tests/test-stream.js
@@ -2,9 +2,15 @@
 
 var o = require("../../ospec/ospec")
 var callAsync = require("../../test-utils/callAsync")
-var Stream = require("../../util/stream")
+var StreamFactory = require("../../util/stream")
 
 o.spec("stream", function() {
+	var Stream, spy
+	o.beforeEach(function() {
+		spy = o.spy()
+		Stream = StreamFactory(spy)
+	})
+	
 	o.spec("stream", function() {
 		o("works as getter/setter", function() {
 			var stream = Stream.stream(1)
@@ -518,11 +524,12 @@ o.spec("stream", function() {
 			o(mapped()).equals(1)
 		})
 		o("works with errored stream", function() {
+			var rejected
 			var stream = Stream.stream(undefined)
-			var mapped = stream.run(function(value) {return Stream.reject(new Error("error"))})
+			var mapped = stream.run(function(value) {
+				return Stream.reject(new Error("error"))
+			})
 
-			mapped.catch(function() {}) //silence reportUncaughtException
-			
 			o(mapped()).equals(undefined)
 			o(mapped.error().message).equals("error")
 		})
@@ -803,14 +810,45 @@ o.spec("stream", function() {
 	})
 	o.spec("toJSON", function() {
 		o("works", function() {
-			o(Stream.stream(1).toJSON()).equals("1")
-			o(Stream.stream("a").toJSON()).equals("\"a\"")
-			o(Stream.stream(true).toJSON()).equals("true")
-			o(Stream.stream(null).toJSON()).equals("null")
+			o(Stream.stream(1).toJSON()).equals(1)
+			o(Stream.stream("a").toJSON()).equals("a")
+			o(Stream.stream(true).toJSON()).equals(true)
+			o(Stream.stream(null).toJSON()).equals(null)
 			o(Stream.stream(undefined).toJSON()).equals(undefined)
-			o(Stream.stream({a: 1}).toJSON()).deepEquals("{\"a\":1}")
-			o(Stream.stream([1, 2, 3]).toJSON()).deepEquals("[1,2,3]")
+			o(Stream.stream({a: 1}).toJSON()).deepEquals({a: 1})
+			o(Stream.stream([1, 2, 3]).toJSON()).deepEquals([1, 2, 3])
 			o(Stream.stream().toJSON()).equals(undefined)
+			o(Stream.stream(new Date(0)).toJSON()).equals(new Date(0).toJSON())
+		})
+		o("works w/ JSON.stringify", function() {
+			o(JSON.stringify(Stream.stream(1))).equals(JSON.stringify(1))
+			o(JSON.stringify(Stream.stream("a"))).equals(JSON.stringify("a"))
+			o(JSON.stringify(Stream.stream(true))).equals(JSON.stringify(true))
+			o(JSON.stringify(Stream.stream(null))).equals(JSON.stringify(null))
+			o(JSON.stringify(Stream.stream(undefined))).equals(JSON.stringify(undefined))
+			o(JSON.stringify(Stream.stream({a: 1}))).deepEquals(JSON.stringify({a: 1}))
+			o(JSON.stringify(Stream.stream([1, 2, 3]))).deepEquals(JSON.stringify([1, 2, 3]))
+			o(JSON.stringify(Stream.stream())).equals(JSON.stringify(undefined))
+			o(JSON.stringify(Stream.stream(new Date(0)))).equals(JSON.stringify(new Date(0)))
+		})
+	})
+	o.spec("uncaught exception reporting", function() {
+		o("reports thrown errors", function(done) {
+			Stream.stream(1).map(function() {throw new Error("error")})
+			
+			setTimeout(function() {
+				o(spy.callCount).equals(1)
+				o(spy.args[0].message).equals("error")
+				done()
+			}, 0)
+		})
+		o("does not report explicit rejections", function(done) {
+			Stream.reject(1)
+			
+			setTimeout(function() {
+				o(spy.callCount).equals(0)
+				done()
+			}, 0)
 		})
 	})
 	o.spec("map", function() {