init

src/compiler/compile/render_dom/Block.ts

@@ -486,7 +486,7 @@ export default class Block {
 				`);
 
 				this.chunks.destroy.push(
-					b`@run_all(${dispose});`
+					b`${dispose}.forEach((#v) => #v());`
 				);
 			}
 		}

src/compiler/compile/render_dom/index.ts

@@ -72,32 +72,48 @@ export default function dom(
 
 	const uses_props = component.var_lookup.has('$$props');
 	const uses_rest = component.var_lookup.has('$$restProps');
-	const $$props = uses_props || uses_rest ? `$$new_props` : `$$props`;
+	const uses_$$ = uses_props || uses_rest;
+	const $$props = uses_$$ ? `$$new_props` : `$$props`;
 	const props = component.vars.filter(variable => !variable.module && variable.export_name);
 	const writable_props = props.filter(variable => variable.writable);
 
 	const omit_props_names = component.get_unique_name('omit_props_names');
-	const compute_rest = x`@compute_rest_props($$props, ${omit_props_names.name})`;
+
 	const rest = uses_rest ? b`
-		const ${omit_props_names.name} = [${props.map(prop => `"${prop.export_name}"`).join(',')}];
+		const ${omit_props_names.name} = [${props.map(prop => `"${prop.export_name}"`)}];
-		let $$restProps = ${compute_rest};
+		const $$restProps = {}; 
+		for (#k in $$props) { 
+			if (!#keys.has(#k) && #k[0] !== '$') { 
+				$$restProps[#k] = $$props[#k];
+			}
+		}
 	` : null;
 
-	const set = (uses_props || uses_rest || writable_props.length > 0 || component.slots.size > 0)
+	const process_new_$$ = b`
-		? x`
+		for (#k in $$new_props) { 
-			${$$props} => {
+			if (#k[0] !== '$') {
-				${uses_props && renderer.invalidate('$$props', x`$$props = @assign(@assign({}, $$props), @exclude_internal_props($$new_props))`)}
+			${uses_rest ? b`
-				${uses_rest && !uses_props && x`$$props = @assign(@assign({}, $$props), @exclude_internal_props($$new_props))`}
+				if (!#keys.has(#k)) { 
-				${uses_rest && renderer.invalidate('$$restProps', x`$$restProps = ${compute_rest}`)}
+					$$props[#k] = ($$restProps[#k] = $$new_props[#k]);
-				${writable_props.map(prop =>
+				} else {
-					b`if ('${prop.export_name}' in ${$$props}) ${renderer.invalidate(prop.name, x`${prop.name} = ${$$props}.${prop.export_name}`)};`
+					$$props[#k] = $$new_props[#k];
-				)}
+				}`
-				${component.slots.size > 0 &&
+			: b`$$props[#k] = $$new_props[#k];`}
-				b`if ('$$scope' in ${$$props}) ${renderer.invalidate('$$scope', x`$$scope = ${$$props}.$$scope`)};`}
 			}
-		`
+		}
-		: null;
+		${uses_props && renderer.invalidate("$$props")}
-
+		${uses_rest && renderer.invalidate("$$restProps")}
+	`
+	
+	const set = (uses_$$ || writable_props.length > 0 || component.slots.size > 0)
+	? x`${$$props} => {
+		${uses_$$ ? process_new_$$ : null}
+		${writable_props.map(prop => b`if ('${prop.export_name}' in ${$$props}) ${renderer.invalidate(prop.name, x`${prop.name} = ${$$props}.${prop.export_name}`)};`)}
+		${component.slots.size > 0 && b`if ('$$scope' in ${$$props}) ${renderer.invalidate('$$scope', x`$$scope = ${$$props}.$$scope`)};`}
+	}`
+	: null;
+			
+	const k = set ? b`let #k;` : null
 	const accessors = [];
 
 	const not_equal = component.component_options.immutable ? x`@not_equal` : x`@safe_not_equal`;
@@ -188,7 +204,7 @@ export default function dom(
 		if (uses_props || injectable_vars.length > 0) {
 			inject_state = x`
 				${$$props} => {
-					${uses_props && renderer.invalidate('$$props', x`$$props = @assign(@assign({}, $$props), $$new_props)`)}
+					${uses_props && renderer.invalidate('$$props', x`$$props = { ...$$props, ...$$new_props }`)}
 					${injectable_vars.map(
 						v => b`if ('${v.name}' in $$props) ${renderer.invalidate(v.name, x`${v.name} = ${$$props}.${v.name}`)};`
 					)}
@@ -251,7 +267,7 @@ export default function dom(
 
 			const insert = (reassigned || export_name)
 				? b`${`$$subscribe_${name}`}()`
-				: b`@component_subscribe($$self, ${name}, #value => $$invalidate(${i}, ${value} = #value))`;
+				: b`$$self.$$.on_destroy.push(@subscribe(${name}, #value => {$$invalidate(${i}, (${value} = #value));})`;
 
 			if (component.compile_options.dev) {
 				return b`@validate_store(${name}, '${name}'); ${insert}`;
@@ -335,7 +351,9 @@ export default function dom(
 		})
 		.map(({ name }) => b`
 			${component.compile_options.dev && b`@validate_store(${name.slice(1)}, '${name.slice(1)}');`}
-			@component_subscribe($$self, ${name.slice(1)}, $$value => $$invalidate(${renderer.context_lookup.get(name).index}, ${name} = $$value));
+			$$self.$$.on_destroy.push(@subscribe(${name.slice(1)}, #value => {
+				$$invalidate(${renderer.context_lookup.get(name).index}, (${name} = #value));
+			}));
 		`);
 
 	const resubscribable_reactive_store_unsubscribers = reactive_stores
@@ -386,7 +404,14 @@ export default function dom(
 				const subscribe = `$$subscribe_${name}`;
 				const i = renderer.context_lookup.get($name).index;
 
-				return b`let ${$name}, ${unsubscribe} = @noop, ${subscribe} = () => (${unsubscribe}(), ${unsubscribe} = @subscribe(${name}, $$value => $$invalidate(${i}, ${$name} = $$value)), ${name})`;
+				return b`
+				let ${$name}, 
+					${unsubscribe} = @noop,
+					${subscribe} = () => { 
+						${unsubscribe}();
+						${unsubscribe} = @subscribe(${name}, (#value) => { $$invalidate(${i}, (${$name} = #value)); });
+						return ${name};
+					};`;
 			}
 
 			return b`let ${$name};`;
@@ -412,6 +437,8 @@ export default function dom(
 
 		body.push(b`
 			function ${definition}(${args}) {
+				${k}
+
 				${rest}
 
 				${reactive_store_declarations}
@@ -449,7 +476,7 @@ export default function dom(
 
 				${fixed_reactive_declarations}
 
-				${uses_props && b`$$props = @exclude_internal_props($$props);`}
+				${uses_props && b`for (#k in $$props) if (#k[0] === '$') delete $$props[#k];`}
 
 				return ${return_value};
 			}

src/compiler/compile/render_dom/wrappers/EachBlock.ts

@@ -604,6 +604,9 @@ export default class EachBlockWrapper extends Wrapper {
 			`);
 		}
 
-		block.chunks.destroy.push(b`@destroy_each(${iterations}, detaching);`);
+		block.chunks.destroy.push(b`
+		for (let #i = 0; #i < ${iterations}.length; #i += 1) {
+			if (${iterations}[#i]) ${iterations}[#i].d(detaching);
+		}`);
 	}
 }

src/compiler/compile/render_dom/wrappers/Element/Attribute.ts

@@ -215,7 +215,7 @@ export default class AttributeWrapper {
 
 		if (scoped_css && rendered.length === 2) {
 			// we have a situation like class={possiblyUndefined}
-			rendered[0] = x`@null_to_empty(${rendered[0]})`;
+			rendered[0] = x`null != ${rendered[0]} ? ${rendered[0]} : ""`;
 		}
 
 		return rendered.reduce((lhs, rhs) => x`${lhs} + ${rhs}`);

src/compiler/compile/render_dom/wrappers/Element/EventHandler.ts

@@ -31,7 +31,7 @@ export default class EventHandlerWrapper {
 
 		if (this.node.reassigned) {
 			block.maintain_context = true;
-			return x`function () { if (@is_function(${snippet})) ${snippet}.apply(this, arguments); }`;
+			return x`function () { if ("function" === typeof (${snippet})) ${snippet}.apply(this, arguments); }`;
 		}
 		return snippet;
 	}

src/compiler/compile/render_dom/wrappers/Element/index.ts

@@ -690,11 +690,10 @@ export default class ElementWrapper extends Wrapper {
 			});
 
 		block.chunks.init.push(b`
-			let ${levels} = [${initial_props}];
+			const ${levels} = [${initial_props}];
-
+			let ${data} = ${levels}[0] || {};
-			let ${data} = {};
+			for (let i = 1; i < ${levels}.length; i++) {
-			for (let #i = 0; #i < ${levels}.length; #i += 1) {
+				${data} = { ...${data}, ...${levels}[i] };
-				${data} = @assign(${data}, ${levels}[#i]);
 			}
 		`);
 

src/compiler/compile/render_dom/wrappers/Head.ts

@@ -36,7 +36,7 @@ export default class HeadWrapper extends Wrapper {
 		let nodes;
 		if (this.renderer.options.hydratable && this.fragment.nodes.length) {
 			nodes = block.get_unique_name('head_nodes');
-			block.chunks.claim.push(b`const ${nodes} = @query_selector_all('[data-svelte="${this.node.id}"]', @_document.head);`);
+			block.chunks.claim.push(b`const ${nodes} = Array.from(( @_document.head || @_document.body ).querySelectorAll('[data-svelte="${this.node.id}"]'));`);
 		}
 
 		this.fragment.render(block, x`@_document.head` as unknown as Identifier, nodes);

src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts

@@ -241,7 +241,7 @@ export default class InlineComponentWrapper extends Wrapper {
 
 						let value_object = value;
 						if (attr.expression.node.type !== 'ObjectExpression') {
-							value_object = x`@get_spread_object(${value})`;
+							value_object = x`typeof (#buffer = ${value}) === 'object' && #buffer !== null ? #buffer : {}`
 						}
 						change_object = value_object;
 					} else {
@@ -265,16 +265,13 @@ export default class InlineComponentWrapper extends Wrapper {
 					];
 				`);
 
-				statements.push(b`
+				statements.push(b`${props} = @_Object.assign(${props}, ...${levels});`);
-					for (let #i = 0; #i < ${levels}.length; #i += 1) {
-						${props} = @assign(${props}, ${levels}[#i]);
-					}
-				`);
 
 				if (all_dependencies.size) {
 					const condition = renderer.dirty(Array.from(all_dependencies));
 
 					updates.push(b`
+						let #buffer;
 						const ${name_changes} = ${condition} ? @get_spread_update(${levels}, [
 							${changes}
 						]) : {}
@@ -424,7 +421,7 @@ export default class InlineComponentWrapper extends Wrapper {
 			`);
 
 			block.chunks.create.push(
-				b`if (${name}) @create_component(${name}.$$.fragment);`
+				b`if (${name} && ${name}.$$.fragment) ${name}.$$.fragment.c();`
 			);
 
 			if (parent_nodes && this.renderer.options.hydratable) {
@@ -465,7 +462,7 @@ export default class InlineComponentWrapper extends Wrapper {
 						${munged_bindings}
 						${munged_handlers}
 
-						@create_component(${name}.$$.fragment);
+						if(${name}.$$.fragment) ${name}.$$.fragment.c();
 						@transition_in(${name}.$$.fragment, 1);
 						@mount_component(${name}, ${update_mount_node}, ${anchor});
 					} else {
@@ -500,11 +497,11 @@ export default class InlineComponentWrapper extends Wrapper {
 				${munged_handlers}
 			`);
 
-			block.chunks.create.push(b`@create_component(${name}.$$.fragment);`);
+			block.chunks.create.push(b`if(${name}.$$.fragment) ${name}.$$.fragment.c();`);
 
 			if (parent_nodes && this.renderer.options.hydratable) {
 				block.chunks.claim.push(
-					b`@claim_component(${name}.$$.fragment, ${parent_nodes});`
+					b`if(${name}.$$.fragment) ${name}.$$.fragment.l(${parent_nodes});`
 				);
 			}
 

src/compiler/compile/render_dom/wrappers/Slot.ts

@@ -126,10 +126,15 @@ export default class SlotWrapper extends Wrapper {
 		const slot = block.get_unique_name(`${sanitize(slot_name)}_slot`);
 		const slot_definition = block.get_unique_name(`${sanitize(slot_name)}_slot_template`);
 		const slot_or_fallback = has_fallback ? block.get_unique_name(`${sanitize(slot_name)}_slot_or_fallback`) : slot;
+		const $$scope = renderer.reference('$$scope');
+		const context = x`
+			${slot_definition}[1] && ${get_slot_context_fn} 
+			? @_Object.assign(${$$scope}.ctx.slice(), ${slot_definition}[1](${get_slot_context_fn}(#ctx))) 
+			: ${$$scope}.ctx`;
 
 		block.chunks.init.push(b`
 			const ${slot_definition} = ${renderer.reference('$$slots')}.${slot_name};
-			const ${slot} = @create_slot(${slot_definition}, #ctx, ${renderer.reference('$$scope')}, ${get_slot_context_fn});
+			const ${slot} = ${slot_definition} && ${slot_definition}[0](${context});
 			${has_fallback ? b`const ${slot_or_fallback} = ${slot} || ${this.fallback.name}(#ctx);` : null}
 		`);
 
@@ -172,7 +177,8 @@ export default class SlotWrapper extends Wrapper {
 
 		const slot_update = b`
 			if (${slot}.p && ${renderer.dirty(dynamic_dependencies)}) {
-				@update_slot(${slot}, ${slot_definition}, #ctx, ${renderer.reference('$$scope')}, #dirty, ${get_slot_changes_fn}, ${get_slot_context_fn});
+				const #changes = @get_slot_changes(${slot_definition}, ${$$scope}, #dirty, ${get_slot_changes_fn})
+				if (#changes) ${slot}.p(${context}, #changes);
 			}
 		`;
 		const fallback_update = has_fallback && fallback_dynamic_dependencies.length > 0 && b`

src/compiler/compile/render_dom/wrappers/shared/add_actions.ts

@@ -29,11 +29,11 @@ export function add_action(block: Block, target: string, action: Action) {
 	const fn = block.renderer.reference(action.name);
 
 	block.event_listeners.push(
-		x`@action_destroyer(${id} = ${fn}.call(null, ${target}, ${snippet}))`
+		x`(${id} = ${fn}.call(null, ${target}, ${snippet})) && 'function' === typeof ${id}.destroy ? ${id}.destroy : @noop`
 	);
 
 	if (dependencies && dependencies.length > 0) {
-		let condition = x`${id} && @is_function(${id}.update)`;
+		let condition = x`${id} && "function" === typeof ${id}.update`;
 
 		if (dependencies.length > 0) {
 			condition = x`${condition} && ${block.renderer.dirty(dependencies)}`;

src/compiler/compile/render_ssr/handlers/AwaitBlock.ts

@@ -13,7 +13,7 @@ export default function(node: AwaitBlock, renderer: Renderer, options: RenderOpt
 
 	renderer.add_expression(x`
 		function(__value) {
-			if (@is_promise(__value)) return ${pending};
+			if (__value && typeof __value === 'object' && typeof __value.then === 'function') return ${pending};
 			return (function(${node.then_node ? node.then_node : ''}) { return ${then}; }(__value));
 		}(${node.expression.node})
 	`);

src/compiler/compile/render_ssr/handlers/shared/get_attribute_value.ts

@@ -9,7 +9,7 @@ export function get_class_attribute_value(attribute: Attribute): ESTreeExpressio
 	// handle special case — `class={possiblyUndefined}` with scoped CSS
 	if (attribute.chunks.length === 2 && (attribute.chunks[1] as Text).synthetic) {
 		const value = (attribute.chunks[0] as Expression).node;
-		return x`@escape(@null_to_empty(${value})) + "${(attribute.chunks[1] as Text).data}"`;
+		return x`(${x`${value} != null ? @escape(${value}) : ""`}) + "${(attribute.chunks[1] as Text).data}"`;
 	}
 
 	return get_attribute_value(attribute);

src/compiler/compile/render_ssr/index.ts

@@ -32,8 +32,14 @@ export default function ssr(
 		component.stylesheet.render(options.filename, true);
 
 	const uses_rest = component.var_lookup.has('$$restProps');
-	const props = component.vars.filter(variable => !variable.module && variable.export_name);
+	const props = component.vars.filter((variable => !variable.module && variable.export_name));
-	const rest = uses_rest ? b`let $$restProps = @compute_rest_props($$props, [${props.map(prop => `"${prop.export_name}"`).join(',')}]);` : null;
+	const rest = uses_rest
+		? b`
+		let #k;
+		const #keys = new Set([${props.map(prop => `"${prop.export_name}"`)}]);
+		let $$restProps = {};
+		for (#k in $$props){ if (!#keys.has(#k) && #k[0] !== '$'){ $$restProps[#k] = $$props[#k];}}`
+		: null;
 
 	const reactive_stores = component.vars.filter(variable => variable.name[0] === '$' && variable.name[1] !== '$');
 	const reactive_store_values = reactive_stores
@@ -42,7 +48,7 @@ export default function ssr(
 			const store = component.var_lookup.get(store_name);
 			if (store && store.hoistable) return null;
 
-			const assignment = b`${name} = @get_store_value(${store_name});`;
+			const assignment = b`@subscribe(${store_name}, (#v) => { ${name} = #v; })();`;
 
 			return component.compile_options.dev
 				? b`@validate_store(${store_name}, '${store_name}'); ${assignment}`
@@ -50,16 +56,12 @@ export default function ssr(
 		})
 		.filter(Boolean);
 
-	component.rewrite_props(({ name }) => {
+	component.rewrite_props(
-		const value = `$${name}`;
+		({ name }) =>
-
+			b`
-		let insert = b`${value} = @get_store_value(${name})`;
+			${component.compile_options.dev && b`@validate_store_dev(${name}, '${name}');`}
-		if (component.compile_options.dev) {
+			@subscribe(${name}, (#v) => { ${`$${name}`} = #v; })();`
-			insert = b`@validate_store(${name}, '${name}'); ${insert}`;
+	);
-		}
-
-		return insert;
-	});
 
 	const instance_javascript = component.extract_javascript(component.ast.instance);
 
@@ -138,10 +140,9 @@ export default function ssr(
 		...reactive_stores.map(({ name }) => {
 			const store_name = name.slice(1);
 			const store = component.var_lookup.get(store_name);
-			if (store && store.hoistable) {
+				return b`
-				return b`let ${name} = @get_store_value(${store_name});`;
+			let ${name}; 
-			}
+			${store && store.hoistable && b`@subscribe(${store_name},(#v) => { ${name}=#v; })();`}`;
-			return b`let ${name};`;
 		}),
 
 		instance_javascript,

src/runtime/animate/index.ts

@@ -1,5 +1,4 @@
 import { cubicOut } from 'svelte/easing';
-import { is_function } from 'svelte/internal';
 
 // todo: same as Transition, should it be shared?
 export interface AnimationConfig {
@@ -35,7 +34,7 @@ export function flip(node: Element, animation: { from: DOMRect; to: DOMRect }, p
 
 	return {
 		delay,
-		duration: is_function(duration) ? duration(d) : duration,
+		duration: typeof duration === "function" ? duration(d) : duration,
 		easing,
 		css: (_t, u) => `transform: ${transform} translate(${u * dx}px, ${u * dy}px);`
 	};

src/runtime/internal/Component.ts

@@ -1,6 +1,6 @@
 import { add_render_callback, flush, schedule_update, dirty_components } from './scheduler';
 import { current_component, set_current_component } from './lifecycle';
-import { blank_object, is_function, run, run_all, noop } from './utils';
+import { noop } from './utils';
 import { children, detach } from './dom';
 import { transition_in } from './transitions';
 
@@ -59,13 +59,13 @@ export function mount_component(component, target, anchor) {
 
 	// onMount happens before the initial afterUpdate
 	add_render_callback(() => {
-		const new_on_destroy = on_mount.map(run).filter(is_function);
+		const new_on_destroy = on_mount.map(v => v()).filter(v => typeof v === "function");
 		if (on_destroy) {
 			on_destroy.push(...new_on_destroy);
 		} else {
 			// Edge case - component was destroyed immediately,
 			// most likely as a result of a binding initialising
-			run_all(new_on_destroy);
+			new_on_destroy.forEach(v => v());
 		}
 		component.$$.on_mount = [];
 	});
@@ -76,7 +76,7 @@ export function mount_component(component, target, anchor) {
 export function destroy_component(component, detaching) {
 	const $$ = component.$$;
 	if ($$.fragment !== null) {
-		run_all($$.on_destroy);
+		$$.on_destroy.forEach(v => v());
 
 		$$.fragment && $$.fragment.d(detaching);
 
@@ -110,7 +110,7 @@ export function init(component, options, instance, create_fragment, not_equal, p
 		props,
 		update: noop,
 		not_equal,
-		bound: blank_object(),
+		bound: Object.create(null),
 
 		// lifecycle
 		on_mount: [],
@@ -120,7 +120,7 @@ export function init(component, options, instance, create_fragment, not_equal, p
 		context: new Map(parent_component ? parent_component.$$.context : []),
 
 		// everything else
-		callbacks: blank_object(),
+		callbacks: Object.create(null),
 		dirty
 	};
 
@@ -139,7 +139,7 @@ export function init(component, options, instance, create_fragment, not_equal, p
 
 	$$.update();
 	ready = true;
-	run_all($$.before_update);
+	$$.before_update.forEach(v => v());
 
 	// `false` as a special case of no DOM component
 	$$.fragment = create_fragment ? create_fragment($$.ctx) : false;

src/runtime/internal/await_block.ts

@@ -1,4 +1,3 @@
-import { is_promise } from './utils';
 import { check_outros, group_outros, transition_in, transition_out } from './transitions';
 import { flush } from './scheduler';
 import { get_current_component, set_current_component } from './lifecycle';
@@ -52,7 +51,7 @@ export function handle_promise(promise, info) {
 		}
 	}
 
-	if (is_promise(promise)) {
+	if (promise && typeof promise === 'object' && typeof promise.then === 'function') {
 		const current_component = get_current_component();
 		promise.then(value => {
 			set_current_component(current_component);

src/runtime/internal/dev.ts

@@ -1,6 +1,12 @@
 import { custom_event, append, insert, detach, listen, attr } from './dom';
 import { SvelteComponent } from './Component';
 
+export function add_location(element, file, line, column, char) {
+	element.__svelte_meta = {
+		loc: { file, line, column, char }
+	};
+}
+
 export function dispatch_dev<T=any>(type: string, detail?: T) {
 	document.dispatchEvent(custom_event(type, { version: '__VERSION__', ...detail }));
 }
@@ -79,6 +85,15 @@ export function set_data_dev(text, data) {
 	text.data = data;
 }
 
+export function validate_component(component, name) {
+	if (!component || !component.$$render) {
+		if (name === 'svelte:component') name += ' this={...}';
+		throw new Error(`<${name}> is not a valid SSR component. You may need to review your build config to ensure that dependencies are compiled, rather than imported as pre-compiled modules`);
+	}
+
+	return component;
+}
+
 export function validate_each_argument(arg) {
 	if (typeof arg !== 'string' && !(arg && typeof arg === 'object' && 'length' in arg)) {
 		let msg = '{#each} only iterates over array-like objects.';
@@ -97,6 +112,24 @@ export function validate_slots(name, slot, keys) {
 	}
 }
 
+export function validate_store(store, name) {
+	if (store != null && typeof store.subscribe !== 'function') {
+		throw new Error(`'${name}' is not a store with a 'subscribe' method`);
+	}
+}
+
+export function validate_each_keys(ctx, list, get_context, get_key) {
+	const keys = new Set();
+	for (let i = 0; i < list.length; i++) {
+		const key = get_key(get_context(ctx, list, i));
+		if (keys.has(key)) {
+			throw new Error(`Cannot have duplicate keys in a keyed each`);
+		}
+		keys.add(key);
+	}
+}
+
+
 type Props = Record<string, any>;
 export interface SvelteComponentDev {
 	$set(props?: Props): void;

src/runtime/internal/dom.ts

@@ -1,5 +1,3 @@
-import { has_prop } from "./utils";
-
 export function append(target: Node, node: Node) {
 	target.appendChild(node);
 }
@@ -26,18 +24,10 @@ export function element_is<K extends keyof HTMLElementTagNameMap>(name: K, is: s
 	return document.createElement<K>(name, { is });
 }
 
-export function object_without_properties<T, K extends keyof T>(obj: T, exclude: K[]) {
+export function object_without_properties<T, K extends string[]>(obj: T, excluded: K) {
-	const target = {} as Pick<T, Exclude<keyof T, K>>;
+	const target = {} as Pick<T, Exclude<keyof T, keyof K>>;
-	for (const k in obj) {
+	let key;
-		if (
+	for (key in obj) if (!~excluded.indexOf(key)) target[key] = obj[key];
-			has_prop(obj, k)
-			// @ts-ignore
-			&& exclude.indexOf(k) === -1
-		) {
-			// @ts-ignore
-			target[k] = obj[k];
-		}
-	}
 	return target;
 }
 
@@ -85,6 +75,15 @@ export function self(fn) {
 	};
 }
 
+export function once(fn) {
+	let ran = false;
+	return function(this: any, ...args) {
+		if (ran) return;
+		ran = true;
+		fn.call(this, ...args);
+	};
+}
+
 export function attr(node: Element, attribute: string, value?: string) {
 	if (value == null) node.removeAttribute(attribute);
 	else if (node.getAttribute(attribute) !== value) node.setAttribute(attribute, value);
@@ -309,10 +308,6 @@ export function custom_event<T=any>(type: string, detail?: T) {
 	return e;
 }
 
-export function query_selector_all(selector: string, parent: HTMLElement = document.body) {
-	return Array.from(parent.querySelectorAll(selector));
-}
-
 export class HtmlTag {
 	e: HTMLElement;
 	n: ChildNode[];

src/runtime/internal/keyed_each.ts

@@ -107,14 +107,3 @@ export function update_keyed_each(old_blocks, dirty, get_key, dynamic, ctx, list
 
 	return new_blocks;
 }
-
-export function validate_each_keys(ctx, list, get_context, get_key) {
-	const keys = new Set();
-	for (let i = 0; i < list.length; i++) {
-		const key = get_key(get_context(ctx, list, i));
-		if (keys.has(key)) {
-			throw new Error(`Cannot have duplicate keys in a keyed each`);
-		}
-		keys.add(key);
-	}
-}

src/runtime/internal/scheduler.ts

@@ -1,4 +1,3 @@
-import { run_all } from './utils';
 import { set_current_component } from './lifecycle';
 
 export const dirty_components = [];
@@ -43,7 +42,15 @@ export function flush() {
 		for (let i = 0; i < dirty_components.length; i += 1) {
 			const component = dirty_components[i];
 			set_current_component(component);
-			update(component.$$);
+			const { $$ } = component
+			if ($$.fragment !== null) {
+				$$.update();
+				$$.before_update.forEach(v => v());
+				const dirty = $$.dirty;
+				$$.dirty = [-1];
+				$$.fragment && $$.fragment.p($$.ctx, dirty);
+				$$.after_update.forEach(add_render_callback);
+			}
 		}
 
 		dirty_components.length = 0;
@@ -75,15 +82,3 @@ export function flush() {
 	flushing = false;
 	seen_callbacks.clear();
 }
-
-function update($$) {
-	if ($$.fragment !== null) {
-		$$.update();
-		run_all($$.before_update);
-		const dirty = $$.dirty;
-		$$.dirty = [-1];
-		$$.fragment && $$.fragment.p($$.ctx, dirty);
-
-		$$.after_update.forEach(add_render_callback);
-	}
-}

src/runtime/internal/spread.ts

@@ -35,7 +35,3 @@ export function get_spread_update(levels, updates) {
 
 	return update;
 }
-
-export function get_spread_object(spread_props) {
-	return typeof spread_props === 'object' && spread_props !== null ? spread_props : {};
-}

src/runtime/internal/ssr.ts

@@ -1,5 +1,4 @@
 import { set_current_component, current_component } from './lifecycle';
-import { run_all, blank_object } from './utils';
 import { boolean_attributes } from '../../compiler/compile/render_ssr/handlers/shared/boolean_attributes';
 
 export const invalid_attribute_name_character = /[\s'">/=\u{FDD0}-\u{FDEF}\u{FFFE}\u{FFFF}\u{1FFFE}\u{1FFFF}\u{2FFFE}\u{2FFFF}\u{3FFFE}\u{3FFFF}\u{4FFFE}\u{4FFFF}\u{5FFFE}\u{5FFFF}\u{6FFFE}\u{6FFFF}\u{7FFFE}\u{7FFFF}\u{8FFFE}\u{8FFFF}\u{9FFFE}\u{9FFFF}\u{AFFFE}\u{AFFFF}\u{BFFFE}\u{BFFFF}\u{CFFFE}\u{CFFFF}\u{DFFFE}\u{DFFFF}\u{EFFFE}\u{EFFFF}\u{FFFFE}\u{FFFFF}\u{10FFFE}\u{10FFFF}]/u;
@@ -56,15 +55,6 @@ export const missing_component = {
 	$$render: () => ''
 };
 
-export function validate_component(component, name) {
-	if (!component || !component.$$render) {
-		if (name === 'svelte:component') name += ' this={...}';
-		throw new Error(`<${name}> is not a valid SSR component. You may need to review your build config to ensure that dependencies are compiled, rather than imported as pre-compiled modules`);
-	}
-
-	return component;
-}
-
 export function debug(file, line, column, values) {
 	console.log(`{@debug} ${file ? file + ' ' : ''}(${line}:${column})`); // eslint-disable-line no-console
 	console.log(values); // eslint-disable-line no-console
@@ -85,7 +75,7 @@ export function create_ssr_component(fn) {
 			on_mount: [],
 			before_update: [],
 			after_update: [],
-			callbacks: blank_object()
+			callbacks: Object.create(null)
 		};
 
 		set_current_component({ $$ });
@@ -111,7 +101,7 @@ export function create_ssr_component(fn) {
 
 			const html = $$render(result, props, {}, options);
 
-			run_all(on_destroy);
+			on_destroy.forEach(v => v());
 
 			return {
 				html,

src/runtime/internal/transitions.ts

@@ -1,4 +1,4 @@
-import { identity as linear, is_function, noop, run_all } from './utils';
+import { identity as linear, noop } from './utils';
 import { now } from "./environment";
 import { loop } from './loop';
 import { create_rule, delete_rule } from './style_manager';
@@ -36,7 +36,7 @@ export function group_outros() {
 
 export function check_outros() {
 	if (!outros.r) {
-		run_all(outros.c);
+		outros.c.forEach(v => v());
 	}
 	outros = outros.p;
 }
@@ -129,7 +129,8 @@ export function create_in_transition(node: Element & ElementCSSInlineStyle, fn:
 
 			delete_rule(node);
 
-			if (is_function(config)) {
+			if (typeof config === "function") {
+				//@ts-ignore
 				config = config();
 				wait().then(go);
 			} else {
@@ -185,7 +186,7 @@ export function create_out_transition(node: Element & ElementCSSInlineStyle, fn:
 					if (!--group.r) {
 						// this will result in `end()` being called,
 						// so we don't need to clean up here
-						run_all(group.c);
+						group.c.forEach(v => v());
 					}
 
 					return false;
@@ -201,7 +202,7 @@ export function create_out_transition(node: Element & ElementCSSInlineStyle, fn:
 		});
 	}
 
-	if (is_function(config)) {
+	if (typeof config === "function") {
 		wait().then(() => {
 			// @ts-ignore
 			config = config();
@@ -313,7 +314,7 @@ export function create_bidirectional_transition(node: Element & ElementCSSInline
 								clear_animation();
 							} else {
 								// outro — needs to be coordinated
-								if (!--running_program.group.r) run_all(running_program.group.c);
+								if (!--running_program.group.r) running_program.group.c.forEach(v => v());
 							}
 						}
 
@@ -334,7 +335,7 @@ export function create_bidirectional_transition(node: Element & ElementCSSInline
 
 	return {
 		run(b) {
-			if (is_function(config)) {
+			if (typeof config === "function") {
 				wait().then(() => {
 					// @ts-ignore
 					config = config();

src/runtime/internal/utils.ts

@@ -2,38 +2,6 @@ export function noop() {}
 
 export const identity = x => x;
 
-export function assign<T, S>(tar: T, src: S): T & S {
-	// @ts-ignore
-	for (const k in src) tar[k] = src[k];
-	return tar as T & S;
-}
-
-export function is_promise<T = any>(value: any): value is PromiseLike<T> {
-	return value && typeof value === 'object' && typeof value.then === 'function';
-}
-
-export function add_location(element, file, line, column, char) {
-	element.__svelte_meta = {
-		loc: { file, line, column, char }
-	};
-}
-
-export function run(fn) {
-	return fn();
-}
-
-export function blank_object() {
-	return Object.create(null);
-}
-
-export function run_all(fns) {
-	fns.forEach(run);
-}
-
-export function is_function(thing: any): thing is Function {
-	return typeof thing === 'function';
-}
-
 export function safe_not_equal(a, b) {
 	return a != a ? b == b : a !== b || ((a && typeof a === 'object') || typeof a === 'function');
 }
@@ -42,10 +10,15 @@ export function not_equal(a, b) {
 	return a != a ? b == b : a !== b;
 }
 
-export function validate_store(store, name) {
+export function get_slot_changes(definition, $$scope, dirty, fn) {
-	if (store != null && typeof store.subscribe !== 'function') {
+	if (!definition[2] || !fn) return $$scope.dirty;
-		throw new Error(`'${name}' is not a store with a 'subscribe' method`);
+	const lets = definition[2](fn(dirty));
-	}
+	if ($$scope.dirty === void 0) return lets;
+	else if (typeof lets === 'object') {
+		const merged = new Array(Math.max($$scope.dirty.length, lets.length));
+		for (let i = 0; i < merged.length; i += 1) merged[i] = $$scope.dirty[i] | lets[i];
+		return merged;
+	} else return $$scope.dirty | lets;
 }
 
 export function subscribe(store, ...callbacks) {
@@ -56,94 +29,7 @@ export function subscribe(store, ...callbacks) {
 	return unsub.unsubscribe ? () => unsub.unsubscribe() : unsub;
 }
 
-export function get_store_value(store) {
-	let value;
-	subscribe(store, _ => value = _)();
-	return value;
-}
-
-export function component_subscribe(component, store, callback) {
-	component.$$.on_destroy.push(subscribe(store, callback));
-}
-
-export function create_slot(definition, ctx, $$scope, fn) {
-	if (definition) {
-		const slot_ctx = get_slot_context(definition, ctx, $$scope, fn);
-		return definition[0](slot_ctx);
-	}
-}
-
-export function get_slot_context(definition, ctx, $$scope, fn) {
-	return definition[1] && fn
-		? assign($$scope.ctx.slice(), definition[1](fn(ctx)))
-		: $$scope.ctx;
-}
-
-export function get_slot_changes(definition, $$scope, dirty, fn) {
-	if (definition[2] && fn) {
-		const lets = definition[2](fn(dirty));
-
-		if ($$scope.dirty === undefined) {
-			return lets;
-		}
-
-		if (typeof lets === 'object') {
-			const merged = [];
-			const len = Math.max($$scope.dirty.length, lets.length);
-			for (let i = 0; i < len; i += 1) {
-				merged[i] = $$scope.dirty[i] | lets[i];
-			}
-
-			return merged;
-		}
-
-		return $$scope.dirty | lets;
-	}
-
-	return $$scope.dirty;
-}
-
-export function update_slot(slot, slot_definition, ctx, $$scope, dirty, get_slot_changes_fn, get_slot_context_fn) {
-	const slot_changes = get_slot_changes(slot_definition, $$scope, dirty, get_slot_changes_fn);
-	if (slot_changes) {
-		const slot_context = get_slot_context(slot_definition, ctx, $$scope, get_slot_context_fn);
-		slot.p(slot_context, slot_changes);
-	}
-}
-
-export function exclude_internal_props(props) {
-	const result = {};
-	for (const k in props) if (k[0] !== '$') result[k] = props[k];
-	return result;
-}
-
-export function compute_rest_props(props, keys) {
-	const rest = {};
-	keys = new Set(keys);
-	for (const k in props) if (!keys.has(k) && k[0] !== '$') rest[k] = props[k];
-	return rest;
-}
-
-export function once(fn) {
-	let ran = false;
-	return function(this: any, ...args) {
-		if (ran) return;
-		ran = true;
-		fn.call(this, ...args);
-	};
-}
-
-export function null_to_empty(value) {
-	return value == null ? '' : value;
-}
-
 export function set_store_value(store, ret, value = ret) {
 	store.set(value);
 	return ret;
 }
-
-export const has_prop = (obj, prop) => Object.prototype.hasOwnProperty.call(obj, prop);
-
-export function action_destroyer(action_result) {
-	return action_result && is_function(action_result.destroy) ? action_result.destroy : noop;
-}

src/runtime/motion/tweened.ts

@@ -1,5 +1,5 @@
 import { Readable, writable } from 'svelte/store';
-import { assign, loop, now, Task } from 'svelte/internal';
+import { loop, now, Task } from 'svelte/internal';
 import { linear } from 'svelte/easing';
 import { is_date } from './utils';
 
@@ -91,7 +91,7 @@ export function tweened<T>(value?: T, defaults: Options<T> = {}): Tweened<T> {
 			duration = 400,
 			easing = linear,
 			interpolate = get_interpolator
-		} = assign(assign({}, defaults), opts);
+		} = { ...defaults, ...opts };
 
 		if (duration === 0) {
 			if (previous_task) {

src/runtime/store/index.ts

@@ -1,4 +1,4 @@
-import { run_all, subscribe, noop, safe_not_equal, is_function, get_store_value } from 'svelte/internal';
+import { subscribe, noop, safe_not_equal } from 'svelte/internal';
 
 /** Callback to inform of a value updates. */
 type Subscriber<T> = (value: T) => void;
@@ -169,7 +169,7 @@ export function derived<T>(stores: Stores, fn: Function, initial_value?: T): Rea
 			if (auto) {
 				set(result as T);
 			} else {
-				cleanup = is_function(result) ? result as Unsubscriber : noop;
+				cleanup = "function" === typeof result ? result as Unsubscriber : noop;
 			}
 		};
 
@@ -191,7 +191,7 @@ export function derived<T>(stores: Stores, fn: Function, initial_value?: T): Rea
 		sync();
 
 		return function stop() {
-			run_all(unsubscribers);
+			unsubscribers.forEach(v => v());
 			cleanup();
 		};
 	});
@@ -201,4 +201,8 @@ export function derived<T>(stores: Stores, fn: Function, initial_value?: T): Rea
  * Get the current value from a store by subscribing and immediately unsubscribing.
  * @param store readable
  */
-export { get_store_value as get };
+export function get(store) {
+	let value;
+	subscribe(store, _ => value = _)();
+	return value;
+}

src/runtime/transition/index.ts

@@ -1,5 +1,4 @@
 import { cubicOut, cubicInOut, linear } from 'svelte/easing';
-import { assign, is_function } from 'svelte/internal';
 
 type EasingFunction = (t: number) => number;
 
@@ -217,7 +216,8 @@ export function crossfade({ fallback, ...defaults }: CrossfadeParams & {
 			delay = 0,
 			duration = d => Math.sqrt(d) * 30,
 			easing = cubicOut
-		} = assign(assign({}, defaults), params);
+			//@ts-ignore
+		} = {...defaults, params};
 
 		const to = node.getBoundingClientRect();
 		const dx = from.left - to.left;
@@ -232,7 +232,7 @@ export function crossfade({ fallback, ...defaults }: CrossfadeParams & {
 
 		return {
 			delay,
-			duration: is_function(duration) ? duration(d) : duration,
+			duration: typeof duration === "function" ? duration(d) : duration,
 			easing,
 			css: (t, u) => `
 				opacity: ${t * opacity};