diff --git a/src/compiler/compile/Component.ts b/src/compiler/compile/Component.ts
index 4443c2679d..7f61df306a 100644
--- a/src/compiler/compile/Component.ts
+++ b/src/compiler/compile/Component.ts
@@ -300,8 +300,13 @@ export default class Component {
 			walk(program, {
 				enter: (node) => {
 					if (node.type === 'Identifier' && node.name[0] === '@') {
-						const alias = this.helper(node.name.slice(1));
-						node.name = alias.name;
+						if (node.name[1] === '_') {
+							const alias = this.global(node.name.slice(2));
+							node.name = alias.name;
+						} else {
+							const alias = this.helper(node.name.slice(1));
+							node.name = alias.name;
+						}
 					}
 				}
 			});
@@ -1223,7 +1228,7 @@ export default class Component {
 	}
 
 	qualify(name) {
-		if (name === `$$props`) return `ctx.$$props`;
+		if (name === `$$props`) return `#ctx.$$props`;
 
 		const variable = this.var_lookup.get(name);
 
@@ -1233,7 +1238,7 @@ export default class Component {
 
 		if (variable.hoistable) return name;
 
-		return `ctx.${name}`;
+		return `#ctx.${name}`;
 	}
 
 	warn_if_undefined(name: string, node, template_scope: TemplateScope) {
diff --git a/src/compiler/compile/create_module.ts b/src/compiler/compile/create_module.ts
index 2e25258835..73ab84bdc1 100644
--- a/src/compiler/compile/create_module.ts
+++ b/src/compiler/compile/create_module.ts
@@ -58,10 +58,11 @@ function esm(
 		source: { type: 'Literal', value: internal_path }
 	}
 
-	const internal_globals = globals.length > 0 &&{
+	const internal_globals = globals.length > 0 && {
 		type: 'VariableDeclaration',
 		kind: 'const',
 		declarations: [{
+			type: 'VariableDeclarator',
 			id: {
 				type: 'ObjectPattern',
 				properties: globals.sort((a, b) => a.name < b.name ? -1 : 1).map(g => ({
@@ -70,10 +71,11 @@ function esm(
 					shorthand: false,
 					computed: false,
 					key: { type: 'Identifier', name: g.name },
-					value: { type: 'Identifier', name: g.alias }
+					value: g.alias,
+					kind: 'init'
 				}))
 			},
-			init: { type: 'Identifier', name: helpers.find(({ name }) => name === 'globals').alias }
+			init: helpers.find(({ name }) => name === 'globals').alias
 		}]
 	};
 
@@ -135,7 +137,7 @@ function cjs(
 		}]
 	};
 
-	const internal_globals = globals.length > 0 &&{
+	const internal_globals = globals.length > 0 && {
 		type: 'VariableDeclaration',
 		kind: 'const',
 		declarations: [{
@@ -148,10 +150,11 @@ function cjs(
 					shorthand: false,
 					computed: false,
 					key: { type: 'Identifier', name: g.name },
-					value: { type: 'Identifier', name: g.alias }
+					value: g.alias,
+					kind: 'init'
 				}))
 			},
-			init: { type: 'Identifier', name: helpers.find(({ name }) => name === 'globals').alias }
+			init: helpers.find(({ name }) => name === 'globals').alias
 		}]
 	};
 
@@ -182,7 +185,7 @@ function cjs(
 	program.body = b`
 		"use strict";
 		${internal_requires}
-		// ${internal_globals}
+		${internal_globals}
 		${user_requires}
 
 		${program.body}
diff --git a/src/compiler/compile/nodes/Binding.ts b/src/compiler/compile/nodes/Binding.ts
index e099f4405a..949b0c657c 100644
--- a/src/compiler/compile/nodes/Binding.ts
+++ b/src/compiler/compile/nodes/Binding.ts
@@ -68,7 +68,7 @@ export default class Binding extends Node {
 			if (!this.expression.node.computed) prop = `'${prop}'`;
 			obj = `[✂${this.expression.node.object.start}-${this.expression.node.object.end}✂]`;
 		} else {
-			obj = 'ctx';
+			obj = '#ctx';
 			prop = `'${name}'`;
 		}
 
diff --git a/src/compiler/compile/nodes/EventHandler.ts b/src/compiler/compile/nodes/EventHandler.ts
index a1adfd345b..3abb2cff54 100644
--- a/src/compiler/compile/nodes/EventHandler.ts
+++ b/src/compiler/compile/nodes/EventHandler.ts
@@ -66,6 +66,6 @@ export default class EventHandler extends Node {
 		if (this.expression) this.expression.manipulate(block);
 
 		// this.component.add_reference(this.handler_name);
-		return `ctx.${this.handler_name}`;
+		return `#ctx.${this.handler_name}`;
 	}
 }
diff --git a/src/compiler/compile/nodes/shared/Expression.ts b/src/compiler/compile/nodes/shared/Expression.ts
index 900a0ba976..7b8ea6a925 100644
--- a/src/compiler/compile/nodes/shared/Expression.ts
+++ b/src/compiler/compile/nodes/shared/Expression.ts
@@ -325,6 +325,16 @@ export default class Expression {
 
 					else {
 						// we need a combo block/init recipe
+						node.params.unshift({
+							type: 'ObjectPattern',
+							properties: Array.from(contextual_dependencies).map(name => ({
+								type: 'Property',
+								kind: 'init',
+								key: { type: 'Identifier', name },
+								value: { type: 'Identifier', name }
+							}))
+						});
+
 						component.partly_hoisted.push(declaration);
 						node.name = id;
 
diff --git a/src/compiler/compile/render_dom/Block.ts b/src/compiler/compile/render_dom/Block.ts
index cde43a8956..f50b412f38 100644
--- a/src/compiler/compile/render_dom/Block.ts
+++ b/src/compiler/compile/render_dom/Block.ts
@@ -1,6 +1,5 @@
 import Renderer from './Renderer';
 import Wrapper from './wrappers/shared/Wrapper';
-import { escape } from '../utils/stringify';
 import { b, x } from 'code-red';
 import { Node, Identifier } from '../../interfaces';
 
@@ -397,16 +396,15 @@ export default class Block {
 	render() {
 		const key = this.key && { type: 'Identifier', name: this.get_unique_name('key') };
 
-		const id = { type: 'Identifier', name: this.name };
 		const args: any[] = [x`#ctx`];
 
 		if (key) args.unshift(key);
 
 		// TODO include this.comment
+		// ${this.comment && `// ${escape(this.comment, { only_escape_at_symbol: true })}`}
 
 		return b`
-			${this.comment && `// ${escape(this.comment, { only_escape_at_symbol: true })}`}
-			function ${id}(${args}) {
+			function ${this.name}(${args}) {
 				${this.get_contents(key)}
 			}
 		`;
diff --git a/src/compiler/compile/render_dom/index.ts b/src/compiler/compile/render_dom/index.ts
index c35d3d317d..7d57a48f91 100644
--- a/src/compiler/compile/render_dom/index.ts
+++ b/src/compiler/compile/render_dom/index.ts
@@ -9,6 +9,7 @@ import { stringify_props } from '../utils/stringify_props';
 import add_to_set from '../utils/add_to_set';
 import { extract_names } from '../utils/scope';
 import { invalidate } from '../utils/invalidate';
+import Block from './Block';
 
 export default function dom(
 	component: Component,
@@ -52,7 +53,12 @@ export default function dom(
 	// TODO the deconflicted names of blocks are reversed... should set them here
 	const blocks = renderer.blocks.slice().reverse();
 
-	body.push(...blocks);
+	body.push(...blocks.map(block => {
+		// TODO this is a horrible mess — renderer.blocks
+		// contains a mixture of Blocks and Nodes
+		if ((block as Block).render) return (block as Block).render();
+		return block;
+	}));
 
 	if (options.dev && !options.hydratable) {
 		block.chunks.claim.push(
@@ -230,7 +236,7 @@ export default function dom(
 	}
 
 	body.push(b`
-		function create_fragment(ctx) {
+		function create_fragment(#ctx) {
 			${block.get_contents()}
 		}
 
diff --git a/src/compiler/compile/render_dom/wrappers/AwaitBlock.ts b/src/compiler/compile/render_dom/wrappers/AwaitBlock.ts
index 9eceea691d..793b9935ab 100644
--- a/src/compiler/compile/render_dom/wrappers/AwaitBlock.ts
+++ b/src/compiler/compile/render_dom/wrappers/AwaitBlock.ts
@@ -137,7 +137,7 @@ export default class AwaitBlockWrapper extends Wrapper {
 		block.maintain_context = true;
 
 		const info_props = [
-			'ctx',
+			'#ctx',
 			'current: null',
 			'token: null',
 			this.pending.block.name && `pending: ${this.pending.block.name}`,
@@ -197,7 +197,7 @@ export default class AwaitBlockWrapper extends Wrapper {
 			);
 
 			block.chunks.update.push(
-				b`${info}.ctx = ctx;`
+				b`${info}.ctx = #ctx;`
 			);
 
 			if (this.pending.block.has_update_method) {
@@ -205,7 +205,7 @@ export default class AwaitBlockWrapper extends Wrapper {
 					if (${conditions.join(' && ')}) {
 						// nothing
 					} else {
-						${info}.block.p(changed, @assign(@assign({}, ctx), ${info}.resolved));
+						${info}.block.p(changed, @assign(@assign({}, #ctx), ${info}.resolved));
 					}
 				`);
 			} else {
@@ -216,7 +216,7 @@ export default class AwaitBlockWrapper extends Wrapper {
 		} else {
 			if (this.pending.block.has_update_method) {
 				block.chunks.update.push(b`
-					${info}.block.p(changed, @assign(@assign({}, ctx), ${info}.resolved));
+					${info}.block.p(changed, @assign(@assign({}, #ctx), ${info}.resolved));
 				`);
 			}
 		}
diff --git a/src/compiler/compile/render_dom/wrappers/EachBlock.ts b/src/compiler/compile/render_dom/wrappers/EachBlock.ts
index 35f6dc6e8d..afc9f678bd 100644
--- a/src/compiler/compile/render_dom/wrappers/EachBlock.ts
+++ b/src/compiler/compile/render_dom/wrappers/EachBlock.ts
@@ -59,7 +59,6 @@ export default class EachBlockWrapper extends Wrapper {
 		fixed_length: number;
 		data_length: string;
 		view_length: string;
-		length: string;
 	}
 
 	context_props: string[];
@@ -104,27 +103,32 @@ export default class EachBlockWrapper extends Wrapper {
 				? node.expression.node.elements.length
 				: null;
 
-		// TODO
 		// hack the sourcemap, so that if data is missing the bug
 		// is easy to find
 		let c = this.node.start + 2;
 		while (renderer.component.source[c] !== 'e') c += 1;
+		const length = {
+			type: 'Identifier',
+			name: 'length',
+			// TODO this format may be incorrect
+			start: c,
+			end: c + 4
+		};
 		// renderer.component.code.overwrite(c, c + 4, 'length');
 
 		const each_block_value = renderer.component.get_unique_name(`${this.var.name}_value`);
-		const iterations = block.get_unique_name(`${this.var}_blocks`);
+		const iterations = block.get_unique_name(`${this.var.name}_blocks`);
 
 		this.vars = {
 			create_each_block: this.block.name,
 			each_block_value,
-			get_each_context: renderer.component.get_unique_name(`get_${this.var}_context`),
+			get_each_context: renderer.component.get_unique_name(`get_${this.var.name}_context`),
 			iterations,
-			length: `[✂${c}-${c+4}✂]`,
 
 			// optimisation for array literal
 			fixed_length,
-			data_length: fixed_length === null ? `${each_block_value}.[✂${c}-${c+4}✂]` : fixed_length,
-			view_length: fixed_length === null ? `${iterations}.[✂${c}-${c+4}✂]` : fixed_length
+			data_length: fixed_length === null ? x`${each_block_value}.${length}` : fixed_length,
+			view_length: fixed_length === null ? x`${iterations}.length` : fixed_length
 		};
 
 		const store =
@@ -185,18 +189,18 @@ export default class EachBlockWrapper extends Wrapper {
 			? !this.next.is_dom_node() :
 			!parent_node || !this.parent.is_dom_node();
 
-		this.context_props = this.node.contexts.map(prop => `child_ctx.${prop.key.name} = ${attach_head('list[i]', prop.tail)};`);
+		this.context_props = this.node.contexts.map(prop => b`child_ctx.${prop.key.name} = ${attach_head('list[i]', prop.tail)};`);
 
-		if (this.node.has_binding) this.context_props.push(`child_ctx.${this.vars.each_block_value} = list;`);
-		if (this.node.has_binding || this.node.index) this.context_props.push(`child_ctx.${this.index_name} = i;`);
+		if (this.node.has_binding) this.context_props.push(b`child_ctx.${this.vars.each_block_value} = list;`);
+		if (this.node.has_binding || this.node.index) this.context_props.push(b`child_ctx.${this.index_name} = i;`);
 
 		const snippet = this.node.expression.manipulate(block);
 
 		block.chunks.init.push(b`let ${this.vars.each_block_value} = ${snippet};`);
 
 		renderer.blocks.push(b`
-			function ${this.vars.get_each_context}(ctx, list, i) {
-				const child_ctx = @_Object.create(ctx);
+			function ${this.vars.get_each_context}(#ctx, list, i) {
+				const child_ctx = @_Object.create(#ctx);
 				${this.context_props}
 				return child_ctx;
 			}
@@ -251,7 +255,7 @@ export default class EachBlockWrapper extends Wrapper {
 			// TODO neaten this up... will end up with an empty line in the block
 			block.chunks.init.push(b`
 				if (!${this.vars.data_length}) {
-					${each_block_else} = ${this.else.block.name}(ctx);
+					${each_block_else} = ${this.else.block.name}(#ctx);
 					${each_block_else}.c();
 				}
 			`);
@@ -265,9 +269,9 @@ export default class EachBlockWrapper extends Wrapper {
 			if (this.else.block.has_update_method) {
 				block.chunks.update.push(b`
 					if (!${this.vars.data_length} && ${each_block_else}) {
-						${each_block_else}.p(changed, ctx);
+						${each_block_else}.p(changed, #ctx);
 					} else if (!${this.vars.data_length}) {
-						${each_block_else} = ${this.else.block.name}(ctx);
+						${each_block_else} = ${this.else.block.name}(#ctx);
 						${each_block_else}.c();
 						${each_block_else}.m(${update_mount_node}, ${update_anchor_node});
 					} else if (${each_block_else}) {
@@ -283,7 +287,7 @@ export default class EachBlockWrapper extends Wrapper {
 							${each_block_else} = null;
 						}
 					} else if (!${each_block_else}) {
-						${each_block_else} = ${this.else.block.name}(ctx);
+						${each_block_else} = ${this.else.block.name}(#ctx);
 						${each_block_else}.c();
 						${each_block_else}.m(${update_mount_node}, ${update_anchor_node});
 					}
@@ -323,8 +327,8 @@ export default class EachBlockWrapper extends Wrapper {
 	}) {
 		const {
 			create_each_block,
-			length,
 			iterations,
+			data_length,
 			view_length
 		} = this.vars;
 
@@ -347,12 +351,12 @@ export default class EachBlockWrapper extends Wrapper {
 		}
 
 		block.chunks.init.push(b`
-			const ${get_key} = ctx => ${
+			const ${get_key} = #ctx => ${
 			// @ts-ignore todo: probably error
 			this.node.key.render()};
 
-			for (let #i = 0; #i < ${this.vars.each_block_value}.${length}; #i += 1) {
-				let child_ctx = ${this.vars.get_each_context}(ctx, ${this.vars.each_block_value}, #i);
+			for (let #i = 0; #i < ${data_length}; #i += 1) {
+				let child_ctx = ${this.vars.get_each_context}(#ctx, ${this.vars.each_block_value}, #i);
 				let key = ${get_key}(child_ctx);
 				${lookup}.set(key, ${iterations}[#i] = ${create_each_block}(key, child_ctx));
 			}
@@ -393,7 +397,7 @@ export default class EachBlockWrapper extends Wrapper {
 
 			${this.block.has_outros && `@group_outros();`}
 			${this.node.has_animation && `for (let #i = 0; #i < ${view_length}; #i += 1) ${iterations}[#i].r();`}
-			${iterations} = @update_keyed_each(${iterations}, changed, ${get_key}, ${dynamic ? '1' : '0'}, ctx, ${this.vars.each_block_value}, ${lookup}, ${update_mount_node}, ${destroy}, ${create_each_block}, ${update_anchor_node}, ${this.vars.get_each_context});
+			${iterations} = @update_keyed_each(${iterations}, changed, ${get_key}, ${dynamic ? '1' : '0'}, #ctx, ${this.vars.each_block_value}, ${lookup}, ${update_mount_node}, ${destroy}, ${create_each_block}, ${update_anchor_node}, ${this.vars.get_each_context});
 			${this.node.has_animation && `for (let #i = 0; #i < ${view_length}; #i += 1) ${iterations}[#i].a();`}
 			${this.block.has_outros && `@check_outros();`}
 		`);
@@ -432,7 +436,6 @@ export default class EachBlockWrapper extends Wrapper {
 	}) {
 		const {
 			create_each_block,
-			length,
 			iterations,
 			fixed_length,
 			data_length,
@@ -443,7 +446,7 @@ export default class EachBlockWrapper extends Wrapper {
 			let ${iterations} = [];
 
 			for (let #i = 0; #i < ${data_length}; #i += 1) {
-				${iterations}[#i] = ${create_each_block}(${this.vars.get_each_context}(ctx, ${this.vars.each_block_value}, #i));
+				${iterations}[#i] = ${create_each_block}(${this.vars.get_each_context}(#ctx, ${this.vars.each_block_value}, #i));
 			}
 		`);
 
@@ -473,13 +476,19 @@ export default class EachBlockWrapper extends Wrapper {
 			all_dependencies.add(dependency);
 		});
 
-		const condition = Array.from(all_dependencies)
-			.map(dependency => `changed.${dependency}`)
-			.join(' || ');
+		let condition;
+		if (all_dependencies.size > 0) {
+			// TODO make this more elegant somehow?
+			const array = Array.from(all_dependencies);
+			let condition = x`#changed.${array[0]}`;
+			for (let i = 1; i < array.length; i += 1) {
+				condition = x`${condition} || #changed.${array[i]}`;
+			}
+		}
 
 		const has_transitions = !!(this.block.has_intro_method || this.block.has_outro_method);
 
-		if (condition !== '') {
+		if (condition) {
 			const for_loop_body = this.block.has_update_method
 				? b`
 					if (${iterations}[#i]) {
@@ -525,17 +534,17 @@ export default class EachBlockWrapper extends Wrapper {
 				`);
 				remove_old_blocks = b`
 					@group_outros();
-					for (#i = ${this.vars.each_block_value}.${length}; #i < ${view_length}; #i += 1) {
+					for (#i = ${data_length}; #i < ${view_length}; #i += 1) {
 						${out}(#i);
 					}
 					@check_outros();
 				`;
 			} else {
 				remove_old_blocks = b`
-					for (${this.block.has_update_method ? `` : `#i = ${this.vars.each_block_value}.${length}`}; #i < ${this.block.has_update_method ? view_length : '#old_length'}; #i += 1) {
+					for (${this.block.has_update_method ? `` : `#i = ${data_length}`}; #i < ${this.block.has_update_method ? view_length : '#old_length'}; #i += 1) {
 						${iterations}[#i].d(1);
 					}
-					${!fixed_length && `${view_length} = ${this.vars.each_block_value}.${length};`}
+					${!fixed_length && `${view_length} = ${data_length};`}
 				`;
 			}
 
@@ -546,8 +555,8 @@ export default class EachBlockWrapper extends Wrapper {
 				${this.vars.each_block_value} = ${snippet};
 
 				let #i;
-				for (#i = ${start}; #i < ${this.vars.each_block_value}.${length}; #i += 1) {
-					const child_ctx = ${this.vars.get_each_context}(ctx, ${this.vars.each_block_value}, #i);
+				for (#i = ${start}; #i < ${data_length}; #i += 1) {
+					const child_ctx = ${this.vars.get_each_context}(#ctx, ${this.vars.each_block_value}, #i);
 
 					${for_loop_body}
 				}
diff --git a/src/compiler/compile/render_dom/wrappers/shared/Tag.ts b/src/compiler/compile/render_dom/wrappers/shared/Tag.ts
index 902074aab7..38ba3f2411 100644
--- a/src/compiler/compile/render_dom/wrappers/shared/Tag.ts
+++ b/src/compiler/compile/render_dom/wrappers/shared/Tag.ts
@@ -1,4 +1,4 @@
-import { b } from 'code-red';
+import { b, x } from 'code-red';
 import Wrapper from './Wrapper';
 import Renderer from '../../Renderer';
 import Block from '../../Block';
@@ -29,16 +29,20 @@ export default class Tag extends Wrapper {
 		if (this.node.should_cache) block.add_variable(value, snippet); // TODO may need to coerce snippet to string
 
 		if (dependencies.length > 0) {
-			const changed_check = (
-				(block.has_outros ? `!#current || ` : '') +
-				dependencies.map((dependency: string) => `changed.${dependency}`).join(' || ')
-			);
+			let condition = x`#changed.${dependencies[0]}`;
+			for (let i = 1; i < dependencies.length; i += 1) {
+				condition = x`${condition} || #changed.${dependencies[i]}`;
+			}
 
-			const update_cached_value = `${value} !== (${value} = ${snippet} + "")`;
+			if (block.has_outros) {
+				condition = x`!#current || ${condition}`;
+			}
 
-			const condition = this.node.should_cache
-				? `(${changed_check}) && ${update_cached_value}`
-				: changed_check;
+			const update_cached_value = x`${value} !== (${value} = ${snippet} + "")`;
+
+			if (this.node.should_cache) {
+				condition = x`${condition} && ${update_cached_value}`;
+			}
 
 			block.chunks.update.push(b`if (${condition}) ${update(content as Node)}`);
 		}
diff --git a/src/runtime/internal/Component.ts b/src/runtime/internal/Component.ts
index ae80ae38c1..5b9007b6bc 100644
--- a/src/runtime/internal/Component.ts
+++ b/src/runtime/internal/Component.ts
@@ -102,6 +102,7 @@ export function init(component, options, instance, create_fragment, not_equal, p
 
 	$$.ctx = instance
 		? instance(component, props, (key, ret, value = ret) => {
+			console.log(`invalidating`, key, ret, value);
 			if ($$.ctx && not_equal($$.ctx[key], $$.ctx[key] = value)) {
 				if ($$.bound[key]) $$.bound[key](value);
 				if (ready) make_dirty(component, key);