diff --git a/src/compiler/compile/Component.ts b/src/compiler/compile/Component.ts
index 2f8874de7a..1bbaac3ff4 100644
--- a/src/compiler/compile/Component.ts
+++ b/src/compiler/compile/Component.ts
@@ -47,6 +47,10 @@ interface ComponentOptions {
 	preserveWhitespace?: boolean;
 }
 
+const regex_leading_directory_separator = /^[/\\]/;
+const regex_starts_with_term_export = /^Export/;
+const regex_contains_term_function = /Function/;
+
 export default class Component {
 	stats: Stats;
 	warnings: Warning[];
@@ -136,7 +140,7 @@ export default class Component {
 			(typeof process !== 'undefined'
 				? compile_options.filename
 					.replace(process.cwd(), '')
-					.replace(/^[/\\]/, '')
+					.replace(regex_leading_directory_separator, '')
 				: compile_options.filename);
 		this.locate = getLocator(this.source, { offsetLine: 1 });
 
@@ -638,7 +642,7 @@ export default class Component {
 				body.splice(i, 1);
 			}
 
-			if (/^Export/.test(node.type)) {
+			if (regex_starts_with_term_export.test(node.type)) {
 				const replacement = this.extract_exports(node, true);
 				if (replacement) {
 					body[i] = replacement;
@@ -795,7 +799,7 @@ export default class Component {
 					return this.skip();
 				}
 
-				if (/^Export/.test(node.type)) {
+				if (regex_starts_with_term_export.test(node.type)) {
 					const replacement = component.extract_exports(node);
 					if (replacement) {
 						this.replace(replacement);
@@ -918,7 +922,7 @@ export default class Component {
 				}
 
 				if (name[1] !== '$' && scope.has(name.slice(1)) && scope.find_owner(name.slice(1)) !== this.instance_scope) {
-					if (!((/Function/.test(parent.type) && prop === 'params') || (parent.type === 'VariableDeclarator' && prop === 'id'))) {
+					if (!((regex_contains_term_function.test(parent.type) && prop === 'params') || (parent.type === 'VariableDeclarator' && prop === 'id'))) {
 						return this.error(node as any, compiler_errors.contextual_store);
 					}
 				}
@@ -965,7 +969,7 @@ export default class Component {
 
 		walk(this.ast.instance.content, {
 			enter(node: Node) {
-				if (/Function/.test(node.type)) {
+				if (regex_contains_term_function.test(node.type)) {
 					return this.skip();
 				}
 
@@ -1089,7 +1093,7 @@ export default class Component {
 
 						this.replace(b`
 							${node.declarations.length ? node : null}
-							${ props.length > 0 && b`let { ${ props } } = $$props;`}
+							${ props.length > 0 && b`let { ${props} } = $$props;`}
 							${inserts}
 						` as any);
 						return this.skip();
@@ -1460,6 +1464,8 @@ export default class Component {
 	}
 }
 
+const regex_valid_tag_name = /^[a-zA-Z][a-zA-Z0-9]*-[a-zA-Z0-9-]+$/;
+
 function process_component_options(component: Component, nodes) {
 	const component_options: ComponentOptions = {
 		immutable: component.compile_options.immutable || false,
@@ -1473,7 +1479,7 @@ function process_component_options(component: Component, nodes) {
 
 	const node = nodes.find(node => node.name === 'svelte:options');
 
-	function get_value(attribute, {code, message}) {
+	function get_value(attribute, { code, message }) {
 		const { value } = attribute;
 		const chunk = value[0];
 
@@ -1505,7 +1511,7 @@ function process_component_options(component: Component, nodes) {
 							return component.error(attribute, compiler_errors.invalid_tag_attribute);
 						}
 
-						if (tag && !/^[a-zA-Z][a-zA-Z0-9]*-[a-zA-Z0-9-]+$/.test(tag)) {
+						if (tag && !regex_valid_tag_name.test(tag)) {
 							return component.error(attribute, compiler_errors.invalid_tag_property);
 						}
 
diff --git a/src/compiler/compile/css/Selector.ts b/src/compiler/compile/css/Selector.ts
index 17302c4abd..28cf5ba6af 100644
--- a/src/compiler/compile/css/Selector.ts
+++ b/src/compiler/compile/css/Selector.ts
@@ -9,6 +9,7 @@ import EachBlock from '../nodes/EachBlock';
 import IfBlock from '../nodes/IfBlock';
 import AwaitBlock from '../nodes/AwaitBlock';
 import compiler_errors from '../compiler_errors';
+import { regex_starts_with_whitespace, regex_ends_with_whitespace } from '../../utils/patterns';
 
 enum BlockAppliesToNode {
 	NotPossible,
@@ -25,6 +26,8 @@ const whitelist_attribute_selector = new Map([
 	['dialog', new Set(['open'])]
 ]);
 
+const regex_is_single_css_selector = /[^\\],(?!([^([]+[^\\]|[^([\\])[)\]])/;
+
 export default class Selector {
 	node: CssNode;
 	stylesheet: Stylesheet;
@@ -157,7 +160,7 @@ export default class Selector {
 		for (const block of this.blocks) {
 			for (const selector of block.selectors) {
 				if (selector.type === 'PseudoClassSelector' && selector.name === 'global') {
-					if (/[^\\],(?!([^([]+[^\\]|[^([\\])[)\]])/.test(selector.children[0].value)) {
+					if (regex_is_single_css_selector.test(selector.children[0].value)) {
 						component.error(selector, compiler_errors.css_invalid_global_selector);
 					}
 				}
@@ -281,12 +284,14 @@ function apply_selector(blocks: Block[], node: Element, to_encapsulate: Array<{
 	return true;
 }
 
+const regex_backslash_and_following_character = /\\(.)/g;
+
 function block_might_apply_to_node(block: Block, node: Element): BlockAppliesToNode {
 	let i = block.selectors.length;
 
 	while (i--) {
 		const selector = block.selectors[i];
-		const name = typeof selector.name === 'string' && selector.name.replace(/\\(.)/g, '$1');
+		const name = typeof selector.name === 'string' && selector.name.replace(regex_backslash_and_following_character, '$1');
 
 		if (selector.type === 'PseudoClassSelector' && (name === 'host' || name === 'root')) {
 			return BlockAppliesToNode.NotPossible;
@@ -371,7 +376,7 @@ function attribute_matches(node: CssNode, name: string, expected_value: string,
 			const start_with_space = [];
 			const remaining = [];
 			current_possible_values.forEach((current_possible_value: string) => {
-				if (/^\s/.test(current_possible_value)) {
+				if (regex_starts_with_whitespace.test(current_possible_value)) {
 					start_with_space.push(current_possible_value);
 				} else {
 					remaining.push(current_possible_value);
@@ -392,7 +397,7 @@ function attribute_matches(node: CssNode, name: string, expected_value: string,
 				prev_values = combined;
 
 				start_with_space.forEach((value: string) => {
-					if (/\s$/.test(value)) {
+					if (regex_ends_with_whitespace.test(value)) {
 						possible_values.add(value);
 					} else {
 						prev_values.push(value);
@@ -406,7 +411,7 @@ function attribute_matches(node: CssNode, name: string, expected_value: string,
 		}
 
 		current_possible_values.forEach((current_possible_value: string) => {
-			if (/\s$/.test(current_possible_value)) {
+			if (regex_ends_with_whitespace.test(current_possible_value)) {
 				possible_values.add(current_possible_value);
 			} else {
 				prev_values.push(current_possible_value);
diff --git a/src/compiler/compile/css/Stylesheet.ts b/src/compiler/compile/css/Stylesheet.ts
index 1a9ea7feeb..9a3cbe9d13 100644
--- a/src/compiler/compile/css/Stylesheet.ts
+++ b/src/compiler/compile/css/Stylesheet.ts
@@ -9,9 +9,12 @@ import hash from '../utils/hash';
 import compiler_warnings from '../compiler_warnings';
 import { extract_ignores_above_position } from '../../utils/extract_svelte_ignore';
 import { push_array } from '../../utils/push_array';
+import { regex_only_whitespaces, regex_whitespace } from '../../utils/patterns';
+
+const regex_css_browser_prefix = /^-((webkit)|(moz)|(o)|(ms))-/;
 
 function remove_css_prefix(name: string): string {
-	return name.replace(/^-((webkit)|(moz)|(o)|(ms))-/, '');
+	return name.replace(regex_css_browser_prefix, '');
 }
 
 const is_keyframes_node = (node: CssNode) =>
@@ -147,10 +150,10 @@ class Declaration {
 
 		// Don't minify whitespace in custom properties, since some browsers (Chromium < 99)
 		// treat --foo: ; and --foo:; differently
-		if (first.type === 'Raw' && /^\s+$/.test(first.value)) return;
+		if (first.type === 'Raw' && regex_only_whitespaces.test(first.value)) return;
 
 		let start = first.start;
-		while (/\s/.test(code.original[start])) start += 1;
+		while (regex_whitespace.test(code.original[start])) start += 1;
 
 		if (start - c > 1) {
 			code.overwrite(c, start, ':');
diff --git a/src/compiler/compile/index.ts b/src/compiler/compile/index.ts
index afe9c56cf4..a5edc3a6f7 100644
--- a/src/compiler/compile/index.ts
+++ b/src/compiler/compile/index.ts
@@ -35,6 +35,9 @@ const valid_options = [
 	'cssHash'
 ];
 
+const regex_valid_identifier = /^[a-zA-Z_$][a-zA-Z_$0-9]*$/;
+const regex_starts_with_lowercase_character = /^[a-z]/;
+
 function validate_options(options: CompileOptions, warnings: Warning[]) {
 	const { name, filename, loopGuardTimeout, dev, namespace } = options;
 
@@ -48,11 +51,11 @@ function validate_options(options: CompileOptions, warnings: Warning[]) {
 		}
 	});
 
-	if (name && !/^[a-zA-Z_$][a-zA-Z_$0-9]*$/.test(name)) {
+	if (name && !regex_valid_identifier.test(name)) {
 		throw new Error(`options.name must be a valid identifier (got '${name}')`);
 	}
 
-	if (name && /^[a-z]/.test(name)) {
+	if (name && regex_starts_with_lowercase_character.test(name)) {
 		const message = 'options.name should be capitalised';
 		warnings.push({
 			code: 'options-lowercase-name',
diff --git a/src/compiler/compile/nodes/Binding.ts b/src/compiler/compile/nodes/Binding.ts
index 594490a5fb..f826df4828 100644
--- a/src/compiler/compile/nodes/Binding.ts
+++ b/src/compiler/compile/nodes/Binding.ts
@@ -3,7 +3,7 @@ import get_object from '../utils/get_object';
 import Expression from './shared/Expression';
 import Component from '../Component';
 import TemplateScope from './shared/TemplateScope';
-import {dimensions} from '../../utils/patterns';
+import { regex_dimensions } from '../../utils/patterns';
 import { Node as ESTreeNode } from 'estree';
 import { TemplateNode } from '../../interfaces';
 import Element from './Element';
@@ -88,7 +88,7 @@ export default class Binding extends Node {
 		const type = parent.get_static_attribute_value('type');
 
 		this.is_readonly =
-			dimensions.test(this.name) ||
+			regex_dimensions.test(this.name) ||
 			(isElement(parent) &&
 				((parent.is_media_node() && read_only_media_attributes.has(this.name)) ||
 					(parent.name === 'input' && type === 'file')) /* TODO others? */);
diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 79f2800437..d5fad18f54 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -11,7 +11,7 @@ import StyleDirective from './StyleDirective';
 import Text from './Text';
 import { namespaces } from '../../utils/namespaces';
 import map_children from './shared/map_children';
-import { dimensions, start_newline } from '../../utils/patterns';
+import { regex_dimensions, regex_starts_with_newline, regex_non_whitespace_character } from '../../utils/patterns';
 import fuzzymatch from '../../utils/fuzzymatch';
 import list from '../../utils/list';
 import Let from './Let';
@@ -203,6 +203,10 @@ function is_valid_aria_attribute_value(schema: ARIAPropertyDefinition, value: st
 	}
 }
 
+const regex_any_repeated_whitespaces = /[\s]+/g;
+const regex_heading_tags = /^h[1-6]$/;
+const regex_illegal_attribute_character = /(^[0-9-.])|[\^$@%&#?!|()[\]{}^*+~;]/;
+
 export default class Element extends Node {
 	type: 'Element';
 	name: string;
@@ -253,7 +257,7 @@ export default class Element extends Node {
 					// places if there's another newline afterwards.
 					// see https://html.spec.whatwg.org/multipage/syntax.html#element-restrictions
 					// see https://html.spec.whatwg.org/multipage/grouping-content.html#the-pre-element
-					first.data = first.data.replace(start_newline, '');
+					first.data = first.data.replace(regex_starts_with_newline, '');
 				}
 			}
 
@@ -398,7 +402,7 @@ export default class Element extends Node {
 
 			// Errors
 
-			if (/(^[0-9-.])|[\^$@%&#?!|()[\]{}^*+~;]/.test(name)) {
+			if (regex_illegal_attribute_character.test(name)) {
 				return component.error(attribute, compiler_errors.illegal_attribute(name));
 			}
 
@@ -464,7 +468,7 @@ export default class Element extends Node {
 					component.warn(attribute, compiler_warnings.a11y_unknown_aria_attribute(type, match));
 				}
 
-				if (name === 'aria-hidden' && /^h[1-6]$/.test(this.name)) {
+				if (name === 'aria-hidden' && regex_heading_tags.test(this.name)) {
 					component.warn(attribute, compiler_warnings.a11y_hidden(this.name));
 				}
 
@@ -729,7 +733,7 @@ export default class Element extends Node {
 		if (this.name === 'figure') {
 			const children = this.children.filter(node => {
 				if (node.type === 'Comment') return false;
-				if (node.type === 'Text') return /\S/.test(node.data);
+				if (node.type === 'Text') return regex_non_whitespace_character.test(node.data);
 				return true;
 			});
 
@@ -861,7 +865,7 @@ export default class Element extends Node {
 				if (this.name !== 'video') {
 					return component.error(binding, compiler_errors.invalid_binding_element_with('<video>', name));
 				}
-			} else if (dimensions.test(name)) {
+			} else if (regex_dimensions.test(name)) {
 				if (this.name === 'svg' && (name === 'offsetWidth' || name === 'offsetHeight')) {
 					return component.error(binding, compiler_errors.invalid_binding_on(binding.name, `<svg>. Use '${name.replace('offset', 'client')}' instead`));
 				} else if (is_svg(this.name)) {
@@ -988,7 +992,7 @@ export default class Element extends Node {
 			if (attribute && !attribute.is_true) {
 				attribute.chunks.forEach((chunk, index) => {
 					if (chunk.type === 'Text') {
-						let data = chunk.data.replace(/[\s\n\t]+/g, ' ');
+						let data = chunk.data.replace(regex_any_repeated_whitespaces, ' ');
 						if (index === 0) {
 							data = data.trimLeft();
 						} else if (index === attribute.chunks.length - 1) {
@@ -1002,12 +1006,14 @@ export default class Element extends Node {
 	}
 }
 
+const regex_starts_with_vovel = /^[aeiou]/;
+
 function should_have_attribute(
 	node,
 	attributes: string[],
 	name = node.name
 ) {
-	const article = /^[aeiou]/.test(attributes[0]) ? 'an' : 'a';
+	const article = regex_starts_with_vovel.test(attributes[0]) ? 'an' : 'a';
 	const sequence = attributes.length > 1 ?
 		attributes.slice(0, -1).join(', ') + ` or ${attributes[attributes.length - 1]}` :
 		attributes[0];
@@ -1015,10 +1021,12 @@ function should_have_attribute(
 	node.component.warn(node, compiler_warnings.a11y_missing_attribute(name, article, sequence));
 }
 
+const regex_minus_sign = /-/;
+
 function within_custom_element(parent: INode) {
 	while (parent) {
 		if (parent.type === 'InlineComponent') return false;
-		if (parent.type === 'Element' && /-/.test(parent.name)) return true;
+		if (parent.type === 'Element' && regex_minus_sign.test(parent.name)) return true;
 		parent = parent.parent;
 	}
 	return false;
diff --git a/src/compiler/compile/nodes/EventHandler.ts b/src/compiler/compile/nodes/EventHandler.ts
index 1bac53b6af..4b426580b3 100644
--- a/src/compiler/compile/nodes/EventHandler.ts
+++ b/src/compiler/compile/nodes/EventHandler.ts
@@ -6,6 +6,8 @@ import { Identifier } from 'estree';
 import TemplateScope from './shared/TemplateScope';
 import { TemplateNode } from '../../interfaces';
 
+const regex_contains_term_function_expression = /FunctionExpression/;
+
 export default class EventHandler extends Node {
 	type: 'EventHandler';
 	name: string;
@@ -25,7 +27,7 @@ export default class EventHandler extends Node {
 			this.expression = new Expression(component, this, template_scope, info.expression);
 			this.uses_context = this.expression.uses_context;
 
-			if (/FunctionExpression/.test(info.expression.type) && info.expression.params.length === 0) {
+			if (regex_contains_term_function_expression.test(info.expression.type) && info.expression.params.length === 0) {
 				// TODO make this detection more accurate — if `event.preventDefault` isn't called, and
 				// `event` is passed to another function, we can make it passive
 				this.can_make_passive = true;
@@ -55,7 +57,7 @@ export default class EventHandler extends Node {
 		}
 		const node = this.expression.node;
 
-		if (/FunctionExpression/.test(node.type)) {
+		if (regex_contains_term_function_expression.test(node.type)) {
 			return false;
 		}
 
diff --git a/src/compiler/compile/nodes/Head.ts b/src/compiler/compile/nodes/Head.ts
index fb000e0d5b..1ebe0c053a 100644
--- a/src/compiler/compile/nodes/Head.ts
+++ b/src/compiler/compile/nodes/Head.ts
@@ -5,6 +5,7 @@ import Component from '../Component';
 import TemplateScope from './shared/TemplateScope';
 import { TemplateNode } from '../../interfaces';
 import compiler_errors from '../compiler_errors';
+import { regex_non_whitespace_character } from '../../utils/patterns';
 
 export default class Head extends Node {
 	type: 'Head';
@@ -20,7 +21,7 @@ export default class Head extends Node {
 		}
 
 		this.children = map_children(component, parent, scope, info.children.filter(child => {
-			return (child.type !== 'Text' || /\S/.test(child.data));
+			return (child.type !== 'Text' || regex_non_whitespace_character.test(child.data));
 		}));
 
 		if (this.children.length > 0) {
diff --git a/src/compiler/compile/nodes/InlineComponent.ts b/src/compiler/compile/nodes/InlineComponent.ts
index 8871c5f306..26cfeb7ef9 100644
--- a/src/compiler/compile/nodes/InlineComponent.ts
+++ b/src/compiler/compile/nodes/InlineComponent.ts
@@ -10,6 +10,7 @@ import TemplateScope from './shared/TemplateScope';
 import { INode } from './interfaces';
 import { TemplateNode } from '../../interfaces';
 import compiler_errors from '../compiler_errors';
+import { regex_only_whitespaces } from '../../utils/patterns';
 
 export default class InlineComponent extends Node {
 	type: 'InlineComponent';
@@ -73,10 +74,10 @@ export default class InlineComponent extends Node {
 
 				case 'Transition':
 					return component.error(node, compiler_errors.invalid_transition);
-				
+
 				case 'StyleDirective':
 					return component.error(node, compiler_errors.invalid_component_style_directive);
-	
+
 				default:
 					throw new Error(`Not implemented: ${node.type}`);
 			}
@@ -165,7 +166,7 @@ export default class InlineComponent extends Node {
 }
 
 function not_whitespace_text(node) {
-	return !(node.type === 'Text' && /^\s+$/.test(node.data));
+	return !(node.type === 'Text' && regex_only_whitespaces.test(node.data));
 }
 
 function get_namespace(parent: Node, explicit_namespace: string) {
diff --git a/src/compiler/compile/nodes/Text.ts b/src/compiler/compile/nodes/Text.ts
index 347beb9c23..ac6cd9b828 100644
--- a/src/compiler/compile/nodes/Text.ts
+++ b/src/compiler/compile/nodes/Text.ts
@@ -3,6 +3,7 @@ import Component from '../Component';
 import TemplateScope from './shared/TemplateScope';
 import { INode } from './interfaces';
 import { TemplateNode } from '../../interfaces';
+import { regex_non_whitespace_character } from '../../utils/patterns';
 
 // Whitespace inside one of these elements will not result in
 // a whitespace node being created in any circumstances. (This
@@ -16,6 +17,8 @@ const elements_without_text = new Set([
 	'video'
 ]);
 
+const regex_ends_with_svg = /svg$/;
+
 export default class Text extends Node {
 	type: 'Text';
 	data: string;
@@ -28,7 +31,7 @@ export default class Text extends Node {
 	}
 
 	should_skip() {
-		if (/\S/.test(this.data)) return false;
+		if (regex_non_whitespace_character.test(this.data)) return false;
 
 		const parent_element = this.find_nearest(/(?:Element|InlineComponent|SlotTemplate|Head)/);
 		if (!parent_element) return false;
@@ -37,7 +40,7 @@ export default class Text extends Node {
 		if (parent_element.type === 'InlineComponent') return parent_element.children.length === 1 && this === parent_element.children[0];
 
 		// svg namespace exclusions
-		if (/svg$/.test(parent_element.namespace)) {
+		if (regex_ends_with_svg.test(parent_element.namespace)) {
 			if (this.prev && this.prev.type === 'Element' && this.prev.name === 'tspan') return false;
 		}
 
diff --git a/src/compiler/compile/nodes/shared/AbstractBlock.ts b/src/compiler/compile/nodes/shared/AbstractBlock.ts
index 04917f5a6b..91af3fc0f7 100644
--- a/src/compiler/compile/nodes/shared/AbstractBlock.ts
+++ b/src/compiler/compile/nodes/shared/AbstractBlock.ts
@@ -4,6 +4,8 @@ import Node from './Node';
 import { INode } from '../interfaces';
 import compiler_warnings from '../../compiler_warnings';
 
+const regex_non_whitespace_characters = /[^ \r\n\f\v\t]/;
+
 export default class AbstractBlock extends Node {
 	block: Block;
 	children: INode[];
@@ -17,7 +19,7 @@ export default class AbstractBlock extends Node {
 
 		const child = this.children[0];
 
-		if (!child || (child.type === 'Text' && !/[^ \r\n\f\v\t]/.test(child.data))) {
+		if (!child || (child.type === 'Text' && !regex_non_whitespace_characters.test(child.data))) {
 			this.component.warn(this, compiler_warnings.empty_block);
 		}
 	}
diff --git a/src/compiler/compile/nodes/shared/Expression.ts b/src/compiler/compile/nodes/shared/Expression.ts
index 0603c15589..6ea509d8b8 100644
--- a/src/compiler/compile/nodes/shared/Expression.ts
+++ b/src/compiler/compile/nodes/shared/Expression.ts
@@ -21,6 +21,8 @@ import compiler_errors from '../../compiler_errors';
 
 type Owner = INode;
 
+const regex_contains_term_function_expression = /FunctionExpression/;
+
 export default class Expression {
 	type: 'Expression' = 'Expression';
 	component: Component;
@@ -72,7 +74,7 @@ export default class Expression {
 					scope = map.get(node);
 				}
 
-				if (!function_expression && /FunctionExpression/.test(node.type)) {
+				if (!function_expression && regex_contains_term_function_expression.test(node.type)) {
 					function_expression = node;
 				}
 
diff --git a/src/compiler/compile/render_dom/Block.ts b/src/compiler/compile/render_dom/Block.ts
index 34c4774804..164e938674 100644
--- a/src/compiler/compile/render_dom/Block.ts
+++ b/src/compiler/compile/render_dom/Block.ts
@@ -3,6 +3,7 @@ import Wrapper from './wrappers/shared/Wrapper';
 import { b, x } from 'code-red';
 import { Node, Identifier, ArrayPattern } from 'estree';
 import { is_head } from './wrappers/shared/is_head';
+import { regex_double_quotes } from '../../utils/patterns';
 
 export interface Bindings {
 	object: Identifier;
@@ -415,7 +416,7 @@ export default class Block {
 						block: ${block},
 						id: ${this.name || 'create_fragment'}.name,
 						type: "${this.type}",
-						source: "${this.comment ? this.comment.replace(/"/g, '\\"') : ''}",
+						source: "${this.comment ? this.comment.replace(regex_double_quotes, '\\"') : ''}",
 						ctx: #ctx
 					});
 					return ${block};`
diff --git a/src/compiler/compile/render_dom/index.ts b/src/compiler/compile/render_dom/index.ts
index 173d93d5dd..c36ca2acd4 100644
--- a/src/compiler/compile/render_dom/index.ts
+++ b/src/compiler/compile/render_dom/index.ts
@@ -12,6 +12,7 @@ import { RawSourceMap, DecodedSourceMap } from '@ampproject/remapping/dist/types
 import { flatten } from '../../utils/flatten';
 import check_enable_sourcemap from '../utils/check_enable_sourcemap';
 import { push_array } from '../../utils/push_array';
+import { regex_backslashes } from '../../utils/patterns';
 
 export default function dom(
 	component: Component,
@@ -530,7 +531,7 @@ export default function dom(
 				constructor(options) {
 					super();
 
-					${css.code && b`this.shadowRoot.innerHTML = \`<style>${css.code.replace(/\\/g, '\\\\')}${css_sourcemap_enabled && options.dev ? `\n/*# sourceMappingURL=${css.map.toUrl()} */` : ''}</style>\`;`}
+					${css.code && b`this.shadowRoot.innerHTML = \`<style>${css.code.replace(regex_backslashes, '\\\\')}${css_sourcemap_enabled && options.dev ? `\n/*# sourceMappingURL=${css.map.toUrl()} */` : ''}</style>\`;`}
 
 					@init(this, { target: this.shadowRoot, props: ${init_props}, customElement: true }, ${definition}, ${has_create_fragment ? 'create_fragment' : 'null'}, ${not_equal}, ${prop_indexes}, null, ${dirty});
 
diff --git a/src/compiler/compile/render_dom/wrappers/Element/Attribute.ts b/src/compiler/compile/render_dom/wrappers/Element/Attribute.ts
index 21a44ab92a..fb604f564e 100644
--- a/src/compiler/compile/render_dom/wrappers/Element/Attribute.ts
+++ b/src/compiler/compile/render_dom/wrappers/Element/Attribute.ts
@@ -10,6 +10,7 @@ import handle_select_value_binding from './handle_select_value_binding';
 import { Identifier, Node } from 'estree';
 import { namespaces } from '../../../../utils/namespaces';
 import { boolean_attributes } from '../../../../../shared/boolean_attributes';
+import { regex_double_quotes } from '../../../../utils/patterns';
 
 const non_textlike_input_types = new Set([
 	'button',
@@ -42,9 +43,12 @@ export class BaseAttributeWrapper {
 		}
 	}
 
-	render(_block: Block) {}
+	render(_block: Block) { }
 }
 
+const regex_minus_sign = /-/;
+const regex_invalid_variable_identifier_characters = /[^a-zA-Z_$]/g;
+
 export default class AttributeWrapper extends BaseAttributeWrapper {
 	node: Attribute;
 	parent: ElementWrapper;
@@ -115,7 +119,7 @@ export default class AttributeWrapper extends BaseAttributeWrapper {
 		// xlink is a special case... we could maybe extend this to generic
 		// namespaced attributes but I'm not sure that's applicable in
 		// HTML5?
-		const method = /-/.test(element.node.name)
+		const method = regex_minus_sign.test(element.node.name)
 			? '@set_custom_element_data'
 			: name.slice(0, 6) === 'xlink:'
 				? '@xlink_attr'
@@ -196,7 +200,7 @@ export default class AttributeWrapper extends BaseAttributeWrapper {
 
 	get_init(block: Block, value) {
 		this.last = this.should_cache && block.get_unique_name(
-			`${this.parent.var.name}_${this.name.replace(/[^a-zA-Z_$]/g, '_')}_value`
+			`${this.parent.var.name}_${this.name.replace(regex_invalid_variable_identifier_characters, '_')}_value`
 		);
 
 		if (this.should_cache) block.add_variable(this.last);
@@ -313,7 +317,7 @@ export default class AttributeWrapper extends BaseAttributeWrapper {
 
 		return `="${value.map(chunk => {
 			return chunk.type === 'Text'
-				? chunk.data.replace(/"/g, '\\"')
+				? chunk.data.replace(regex_double_quotes, '\\"')
 				: `\${${chunk.manipulate()}}`;
 		}).join('')}"`;
 	}
@@ -381,13 +385,14 @@ function should_cache(attribute: AttributeWrapper) {
 	return attribute.is_src || attribute.node.should_cache();
 }
 
+const regex_contains_checked_or_group = /checked|group/;
+
 function is_indirectly_bound_value(attribute: AttributeWrapper) {
 	const element = attribute.parent;
 	return attribute.name === 'value' &&
 		(element.node.name === 'option' || // TODO check it's actually bound
 			(element.node.name === 'input' &&
 				element.node.bindings.some(
-					(binding) =>
-						/checked|group/.test(binding.name)
+					(binding) => regex_contains_checked_or_group.test(binding.name)
 				)));
 }
diff --git a/src/compiler/compile/render_dom/wrappers/Element/StyleAttribute.ts b/src/compiler/compile/render_dom/wrappers/Element/StyleAttribute.ts
index ac7f66b6ac..4481b6b98f 100644
--- a/src/compiler/compile/render_dom/wrappers/Element/StyleAttribute.ts
+++ b/src/compiler/compile/render_dom/wrappers/Element/StyleAttribute.ts
@@ -69,6 +69,8 @@ export default class StyleAttributeWrapper extends AttributeWrapper {
 	}
 }
 
+const regex_style_prop_key = /^\s*([\w-]+):\s*/;
+
 function optimize_style(value: Array<Text | Expression>) {
 	const props: StyleProp[] = [];
 	let chunks = value.slice();
@@ -78,7 +80,7 @@ function optimize_style(value: Array<Text | Expression>) {
 
 		if (chunk.type !== 'Text') return null;
 
-		const key_match = /^\s*([\w-]+):\s*/.exec(chunk.data);
+		const key_match = regex_style_prop_key.exec(chunk.data);
 		if (!key_match) return null;
 
 		const key = key_match[1];
@@ -106,6 +108,9 @@ function optimize_style(value: Array<Text | Expression>) {
 	return props;
 }
 
+const regex_important_flag = /\s*!important\s*$/;
+const regex_semicolon_or_whitespace = /[;\s]/;
+
 function get_style_value(chunks: Array<Text | Expression>) {
 	const value: Array<Text | Expression> = [];
 
@@ -151,7 +156,7 @@ function get_style_value(chunks: Array<Text | Expression>) {
 				} as Text);
 			}
 
-			while (/[;\s]/.test(chunk.data[c])) c += 1;
+			while (regex_semicolon_or_whitespace.test(chunk.data[c])) c += 1;
 			const remaining_data = chunk.data.slice(c);
 
 			if (remaining_data) {
@@ -172,9 +177,9 @@ function get_style_value(chunks: Array<Text | Expression>) {
 	let important = false;
 
 	const last_chunk = value[value.length - 1];
-	if (last_chunk && last_chunk.type === 'Text' && /\s*!important\s*$/.test(last_chunk.data)) {
+	if (last_chunk && last_chunk.type === 'Text' && regex_important_flag.test(last_chunk.data)) {
 		important = true;
-		last_chunk.data = last_chunk.data.replace(/\s*!important\s*$/, '');
+		last_chunk.data = last_chunk.data.replace(regex_important_flag, '');
 		if (!last_chunk.data) value.pop();
 	}
 
diff --git a/src/compiler/compile/render_dom/wrappers/Element/index.ts b/src/compiler/compile/render_dom/wrappers/Element/index.ts
index 4f0b49729c..01f03b5589 100644
--- a/src/compiler/compile/render_dom/wrappers/Element/index.ts
+++ b/src/compiler/compile/render_dom/wrappers/Element/index.ts
@@ -12,7 +12,7 @@ import { namespaces } from '../../../../utils/namespaces';
 import AttributeWrapper from './Attribute';
 import StyleAttributeWrapper from './StyleAttribute';
 import SpreadAttributeWrapper from './SpreadAttribute';
-import { dimensions, start_newline } from '../../../../utils/patterns';
+import { regex_dimensions, regex_starts_with_newline, regex_backslashes } from '../../../../utils/patterns';
 import Binding from './Binding';
 import add_to_set from '../../../utils/add_to_set';
 import { add_event_handler } from '../shared/add_event_handlers';
@@ -34,12 +34,16 @@ interface BindingGroup {
 	bindings: Binding[];
 }
 
+const regex_contains_radio_or_checkbox_or_file = /radio|checkbox|file/;
+const regex_contains_radio_or_checkbox_or_range_or_file = /radio|checkbox|range|file/;
+
 const events = [
 	{
 		event_names: ['input'],
 		filter: (node: Element, _name: string) =>
 			node.name === 'textarea' ||
-			node.name === 'input' && !/radio|checkbox|range|file/.test(node.get_static_attribute_value('type') as string)
+			node.name === 'input' &&
+			!regex_contains_radio_or_checkbox_or_range_or_file.test(node.get_static_attribute_value('type') as string)
 	},
 	{
 		event_names: ['input'],
@@ -51,7 +55,8 @@ const events = [
 		event_names: ['change'],
 		filter: (node: Element, _name: string) =>
 			node.name === 'select' ||
-			node.name === 'input' && /radio|checkbox|file/.test(node.get_static_attribute_value('type') as string)
+			node.name === 'input' &&
+			regex_contains_radio_or_checkbox_or_file.test(node.get_static_attribute_value('type') as string)
 	},
 	{
 		event_names: ['change', 'input'],
@@ -62,7 +67,7 @@ const events = [
 	{
 		event_names: ['elementresize'],
 		filter: (_node: Element, name: string) =>
-			dimensions.test(name)
+			regex_dimensions.test(name)
 	},
 
 	// media events
@@ -136,6 +141,8 @@ const events = [
 ];
 
 const CHILD_DYNAMIC_ELEMENT_BLOCK = 'child_dynamic_element';
+const regex_invalid_variable_identifier_characters = /[^a-zA-Z0-9_$]/g;
+const regex_minus_signs = /-/g;
 
 export default class ElementWrapper extends Wrapper {
 	node: Element;
@@ -182,7 +189,7 @@ export default class ElementWrapper extends Wrapper {
 
 		this.var = {
 			type: 'Identifier',
-			name: node.name.replace(/[^a-zA-Z0-9_$]/g, '_')
+			name: node.name.replace(regex_invalid_variable_identifier_characters, '_')
 		};
 
 		this.void = is_void(node.name);
@@ -547,7 +554,7 @@ export default class ElementWrapper extends Wrapper {
 		}
 	}
 
-	add_directives_in_order (block: Block) {
+	add_directives_in_order(block: Block) {
 		type OrderedAttribute = EventHandler | BindingGroup | Binding | Action;
 
 		const binding_groups = events
@@ -561,7 +568,7 @@ export default class ElementWrapper extends Wrapper {
 
 		const this_binding = this.bindings.find(b => b.node.name === 'this');
 
-		function getOrder (item: OrderedAttribute) {
+		function getOrder(item: OrderedAttribute) {
 			if (item instanceof EventHandler) {
 				return item.node.start;
 			} else if (item instanceof Binding) {
@@ -1100,7 +1107,7 @@ export default class ElementWrapper extends Wrapper {
 			const snippet = expression.manipulate(block);
 			let cached_snippet;
 			if (should_cache) {
-				cached_snippet = block.get_unique_name(`style_${name.replace(/-/g, '_')}`);
+				cached_snippet = block.get_unique_name(`style_${name.replace(regex_minus_signs, '_')}`);
 				block.add_variable(cached_snippet, snippet);
 			}
 
@@ -1138,6 +1145,9 @@ export default class ElementWrapper extends Wrapper {
 	}
 }
 
+const regex_backticks = /`/g;
+const regex_dollar_signs = /\$/g;
+
 function to_html(wrappers: Array<ElementWrapper | TextWrapper | MustacheTagWrapper | RawMustacheTagWrapper>, block: Block, literal: any, state: any, can_use_raw_text?: boolean) {
 	wrappers.forEach(wrapper => {
 		if (wrapper instanceof TextWrapper) {
@@ -1155,9 +1165,9 @@ function to_html(wrappers: Array<ElementWrapper | TextWrapper | MustacheTagWrapp
 			);
 
 			state.quasi.value.raw += (raw ? wrapper.data : escape_html(wrapper.data))
-				.replace(/\\/g, '\\\\')
-				.replace(/`/g, '\\`')
-				.replace(/\$/g, '\\$');
+				.replace(regex_backslashes, '\\\\')
+				.replace(regex_backticks, '\\`')
+				.replace(regex_dollar_signs, '\\$');
 		} else if (wrapper instanceof MustacheTagWrapper || wrapper instanceof RawMustacheTagWrapper) {
 			literal.quasis.push(state.quasi);
 			literal.expressions.push(wrapper.node.expression.manipulate(block));
@@ -1192,7 +1202,7 @@ function to_html(wrappers: Array<ElementWrapper | TextWrapper | MustacheTagWrapp
 					// Two or more leading newlines are required to restore the leading newline immediately after `<pre>`.
 					// see https://html.spec.whatwg.org/multipage/grouping-content.html#the-pre-element
 					const first = wrapper.fragment.nodes[0];
-					if (first && first.node.type === 'Text' && start_newline.test(first.node.data)) {
+					if (first && first.node.type === 'Text' && regex_starts_with_newline.test(first.node.data)) {
 						state.quasi.value.raw += '\n';
 					}
 				}
@@ -1204,7 +1214,7 @@ function to_html(wrappers: Array<ElementWrapper | TextWrapper | MustacheTagWrapp
 						// Two or more leading newlines are required to restore the leading newline immediately after `<textarea>`.
 						// see https://html.spec.whatwg.org/multipage/syntax.html#element-restrictions
 						const first = value_attribute.node.chunks[0];
-						if (first && first.type === 'Text' && start_newline.test(first.data)) {
+						if (first && first.type === 'Text' && regex_starts_with_newline.test(first.data)) {
 							state.quasi.value.raw += '\n';
 						}
 						to_html_for_attr_value(value_attribute, block, literal, state);
diff --git a/src/compiler/compile/render_dom/wrappers/Fragment.ts b/src/compiler/compile/render_dom/wrappers/Fragment.ts
index 87ce775ca9..1e3b89e97f 100644
--- a/src/compiler/compile/render_dom/wrappers/Fragment.ts
+++ b/src/compiler/compile/render_dom/wrappers/Fragment.ts
@@ -21,6 +21,7 @@ import Block from '../Block';
 import { trim_start, trim_end } from '../../../utils/trim';
 import { link } from '../../../utils/link';
 import { Identifier } from 'estree';
+import { regex_starts_with_whitespace } from '../../../utils/patterns';
 
 const wrappers = {
 	AwaitBlock,
@@ -92,7 +93,7 @@ export default class FragmentWrapper {
 				// *unless* there is no whitespace between this node and its next sibling
 				if (this.nodes.length === 0) {
 					const should_trim = (
-						next_sibling ? (next_sibling.node.type === 'Text' && /^\s/.test(next_sibling.node.data) && trimmable_at(child, next_sibling)) : !child.has_ancestor('EachBlock')
+						next_sibling ? (next_sibling.node.type === 'Text' && regex_starts_with_whitespace.test(next_sibling.node.data) && trimmable_at(child, next_sibling)) : !child.has_ancestor('EachBlock')
 					);
 
 					if (should_trim && !child.keep_space()) {
diff --git a/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts b/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
index 37aaf2e7b2..37416379c9 100644
--- a/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
+++ b/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
@@ -24,6 +24,8 @@ import { namespaces } from '../../../../utils/namespaces';
 
 type SlotDefinition = { block: Block; scope: TemplateScope; get_context?: Node; get_changes?: Node };
 
+const regex_invalid_variable_identifier_characters = /[^a-zA-Z_$]/g;
+
 export default class InlineComponentWrapper extends Wrapper {
 	var: Identifier;
 	slots: Map<string, SlotDefinition> = new Map();
@@ -596,7 +598,7 @@ export default class InlineComponentWrapper extends Wrapper {
 		this.node.css_custom_properties.forEach((attr) => {
 			const dependencies = attr.get_dependencies();
 			const should_cache = attr.should_cache();
-			const last = should_cache &&	block.get_unique_name(`${attr.name.replace(/[^a-zA-Z_$]/g, '_')}_last`);
+			const last = should_cache &&	block.get_unique_name(`${attr.name.replace(regex_invalid_variable_identifier_characters, '_')}_last`);
 			if (should_cache) block.add_variable(last);
 			const value = attr.get_value(block);
 			const init = should_cache ? x`${last} = ${value}` : value;
diff --git a/src/compiler/compile/render_dom/wrappers/Text.ts b/src/compiler/compile/render_dom/wrappers/Text.ts
index 2a342b5678..7d02735d9a 100644
--- a/src/compiler/compile/render_dom/wrappers/Text.ts
+++ b/src/compiler/compile/render_dom/wrappers/Text.ts
@@ -5,6 +5,8 @@ import Wrapper from './shared/Wrapper';
 import { x } from 'code-red';
 import { Identifier } from 'estree';
 
+const regex_non_whitespace_characters = /[\S\u00A0]/;
+
 export default class TextWrapper extends Wrapper {
 	node: Text;
 	data: string;
@@ -27,7 +29,7 @@ export default class TextWrapper extends Wrapper {
 
 	use_space() {
 		if (this.renderer.component.component_options.preserveWhitespace) return false;
-		if (/[\S\u00A0]/.test(this.data)) return false;
+		if (regex_non_whitespace_characters.test(this.data)) return false;
 
 		return !this.node.within_pre();
 	}
diff --git a/src/compiler/compile/render_dom/wrappers/shared/add_actions.ts b/src/compiler/compile/render_dom/wrappers/shared/add_actions.ts
index 6429f18928..3b39494994 100644
--- a/src/compiler/compile/render_dom/wrappers/shared/add_actions.ts
+++ b/src/compiler/compile/render_dom/wrappers/shared/add_actions.ts
@@ -12,6 +12,8 @@ export default function add_actions(
 	actions.forEach(action => add_action(block, target, action));
 }
 
+const regex_invalid_variable_identifier_characters = /[^a-zA-Z0-9_$]/g;
+
 export function add_action(block: Block, target: string | Expression, action: Action) {
 	const { expression, template_scope } = action;
 	let snippet;
@@ -23,7 +25,7 @@ export function add_action(block: Block, target: string | Expression, action: Ac
 	}
 
 	const id = block.get_unique_name(
-		`${action.name.replace(/[^a-zA-Z0-9_$]/g, '_')}_action`
+		`${action.name.replace(regex_invalid_variable_identifier_characters, '_')}_action`
 	);
 
 	block.add_variable(id);
diff --git a/src/compiler/compile/render_dom/wrappers/shared/create_debugging_comment.ts b/src/compiler/compile/render_dom/wrappers/shared/create_debugging_comment.ts
index 8e9f7fab37..6512b42862 100644
--- a/src/compiler/compile/render_dom/wrappers/shared/create_debugging_comment.ts
+++ b/src/compiler/compile/render_dom/wrappers/shared/create_debugging_comment.ts
@@ -1,5 +1,7 @@
 import Component from '../../../Component';
 import { INode } from '../../../nodes/interfaces';
+import { regex_whitespace_characters } from '../../../../utils/patterns';
+
 
 export default function create_debugging_comment(
 	node: INode,
@@ -36,5 +38,5 @@ export default function create_debugging_comment(
 	const start = locate(c);
 	const loc = `(${start.line}:${start.column})`;
 
-	return `${loc} ${source.slice(c, d)}`.replace(/\s/g, ' ');
+	return `${loc} ${source.slice(c, d)}`.replace(regex_whitespace_characters, ' ');
 }
diff --git a/src/compiler/compile/render_ssr/handlers/Element.ts b/src/compiler/compile/render_ssr/handlers/Element.ts
index 2af0343b2a..081988b567 100644
--- a/src/compiler/compile/render_ssr/handlers/Element.ts
+++ b/src/compiler/compile/render_ssr/handlers/Element.ts
@@ -8,7 +8,7 @@ import Expression from '../../nodes/shared/Expression';
 import remove_whitespace_children from './utils/remove_whitespace_children';
 import fix_attribute_casing from '../../render_dom/wrappers/Element/fix_attribute_casing';
 import { namespaces } from '../../../utils/namespaces';
-import { start_newline } from '../../../utils/patterns';
+import { regex_starts_with_newline } from '../../../utils/patterns';
 import { Node, Expression as ESExpression } from 'estree';
 
 export default function (node: Element, renderer: Renderer, options: RenderOptions) {
@@ -173,7 +173,7 @@ export default function (node: Element, renderer: Renderer, options: RenderOptio
 				const value_attribute = node.attributes.find(({ name }) => name === 'value');
 				if (value_attribute) {
 					const first = value_attribute.chunks[0];
-					if (first && first.type === 'Text' && start_newline.test(first.data)) {
+					if (first && first.type === 'Text' && regex_starts_with_newline.test(first.data)) {
 						renderer.add_string('\n');
 					}
 				}
@@ -188,7 +188,7 @@ export default function (node: Element, renderer: Renderer, options: RenderOptio
 			// see https://html.spec.whatwg.org/multipage/grouping-content.html#the-pre-element
 			// see https://html.spec.whatwg.org/multipage/syntax.html#element-restrictions
 			const first = children[0];
-			if (first && first.type === 'Text' && start_newline.test(first.data)) {
+			if (first && first.type === 'Text' && regex_starts_with_newline.test(first.data)) {
 				renderer.add_string('\n');
 			}
 		}
diff --git a/src/compiler/compile/render_ssr/handlers/shared/get_attribute_value.ts b/src/compiler/compile/render_ssr/handlers/shared/get_attribute_value.ts
index 20d4eddbc5..f431ea01db 100644
--- a/src/compiler/compile/render_ssr/handlers/shared/get_attribute_value.ts
+++ b/src/compiler/compile/render_ssr/handlers/shared/get_attribute_value.ts
@@ -4,6 +4,7 @@ import Text from '../../../nodes/Text';
 import { x } from 'code-red';
 import Expression from '../../../nodes/shared/Expression';
 import { Expression as ESTreeExpression } from 'estree';
+import { regex_double_quotes } from '../../../../utils/patterns';
 
 export function get_class_attribute_value(attribute: Attribute): ESTreeExpression {
 	// handle special case — `class={possiblyUndefined}` with scoped CSS
@@ -21,7 +22,7 @@ export function get_attribute_value(attribute: Attribute): ESTreeExpression {
 	return attribute.chunks
 		.map((chunk) => {
 			return chunk.type === 'Text'
-				? string_literal(chunk.data.replace(/"/g, '&quot;')) as ESTreeExpression
+				? string_literal(chunk.data.replace(regex_double_quotes, '&quot;')) as ESTreeExpression
 				: x`@escape(${chunk.node}, true)`;
 		})
 		.reduce((lhs, rhs) => x`${lhs} + ${rhs}`);
diff --git a/src/compiler/compile/render_ssr/handlers/utils/remove_whitespace_children.ts b/src/compiler/compile/render_ssr/handlers/utils/remove_whitespace_children.ts
index 7733c89cb8..10ccaefa92 100644
--- a/src/compiler/compile/render_ssr/handlers/utils/remove_whitespace_children.ts
+++ b/src/compiler/compile/render_ssr/handlers/utils/remove_whitespace_children.ts
@@ -1,6 +1,7 @@
 import { INode } from '../../../nodes/interfaces';
 import { trim_end, trim_start } from '../../../../utils/trim';
 import { link } from '../../../../utils/link';
+import { regex_starts_with_whitespace } from '../../../../utils/patterns';
 
 // similar logic from `compile/render_dom/wrappers/Fragment`
 // We want to remove trailing whitespace inside an element/component/block,
@@ -22,7 +23,7 @@ export default function remove_whitespace_children(children: INode[], next?: INo
 			if (nodes.length === 0) {
 				const should_trim = next
 					? next.type === 'Text' &&
-					  /^\s/.test(next.data) &&
+					regex_starts_with_whitespace.test(next.data) &&
 					  trimmable_at(child, next)
 					: !child.has_ancestor('EachBlock');
 
diff --git a/src/compiler/compile/utils/get_name_from_filename.ts b/src/compiler/compile/utils/get_name_from_filename.ts
index b05605b5ee..7c0f805b76 100644
--- a/src/compiler/compile/utils/get_name_from_filename.ts
+++ b/src/compiler/compile/utils/get_name_from_filename.ts
@@ -1,3 +1,10 @@
+import { regex_starts_with_underscore, regex_ends_with_underscore } from '../../utils/patterns';
+
+const regex_percentage_characters = /%/g;
+const regex_file_ending = /\.[^.]+$/;
+const regex_repeated_invalid_variable_identifier_characters = /[^a-zA-Z_$0-9]+/g;
+const regex_starts_with_digit = /^(\d)/;
+
 export default function get_name_from_filename(filename: string) {
 	if (!filename) return null;
 
@@ -12,12 +19,12 @@ export default function get_name_from_filename(filename: string) {
 	}
 
 	const base = parts.pop()
-		.replace(/%/g, 'u')
-		.replace(/\.[^.]+$/, '')
-		.replace(/[^a-zA-Z_$0-9]+/g, '_')
-		.replace(/^_/, '')
-		.replace(/_$/, '')
-		.replace(/^(\d)/, '_$1');
+		.replace(regex_percentage_characters, 'u')
+		.replace(regex_file_ending, '')
+		.replace(regex_repeated_invalid_variable_identifier_characters, '_')
+		.replace(regex_starts_with_underscore, '')
+		.replace(regex_ends_with_underscore, '')
+		.replace(regex_starts_with_digit, '_$1');
 
 	if (!base) {
 		throw new Error(`Could not derive component name from file ${filename}`);
diff --git a/src/compiler/compile/utils/hash.ts b/src/compiler/compile/utils/hash.ts
index c0ea2b3d88..d5b5a20609 100644
--- a/src/compiler/compile/utils/hash.ts
+++ b/src/compiler/compile/utils/hash.ts
@@ -1,6 +1,9 @@
 // https://github.com/darkskyapp/string-hash/blob/master/index.js
+
+const regex_return_characters = /\r/g;
+
 export default function hash(str: string): string {
-	str = str.replace(/\r/g, '');
+	str = str.replace(regex_return_characters, '');
 	let hash = 5381;
 	let i = str.length;
 
diff --git a/src/compiler/compile/utils/stringify.ts b/src/compiler/compile/utils/stringify.ts
index aa1c42c512..84073c6469 100644
--- a/src/compiler/compile/utils/stringify.ts
+++ b/src/compiler/compile/utils/stringify.ts
@@ -19,10 +19,14 @@ const escaped = {
 	'>': '&gt;'
 };
 
+const regex_html_characters_to_escape = /["'&<>]/g;
+
 export function escape_html(html) {
-	return String(html).replace(/["'&<>]/g, match => escaped[match]);
+	return String(html).replace(regex_html_characters_to_escape, match => escaped[match]);
 }
 
+const regex_template_characters_to_escape = /(\${|`|\\)/g;
+
 export function escape_template(str) {
-	return str.replace(/(\${|`|\\)/g, '\\$1');
+	return str.replace(regex_template_characters_to_escape, '\\$1');
 }
diff --git a/src/compiler/parse/index.ts b/src/compiler/parse/index.ts
index e5e2260bc0..079be0e20c 100644
--- a/src/compiler/parse/index.ts
+++ b/src/compiler/parse/index.ts
@@ -1,6 +1,6 @@
 import { isIdentifierStart, isIdentifierChar } from 'acorn';
 import fragment from './state/fragment';
-import { whitespace } from '../utils/patterns';
+import { regex_whitespace } from '../utils/patterns';
 import { reserved } from '../utils/names';
 import full_char_code_at from '../utils/full_char_code_at';
 import { TemplateNode, Ast, ParserOptions, Fragment, Style, Script } from '../interfaces';
@@ -15,6 +15,8 @@ interface LastAutoClosedTag {
 	depth: number;
 }
 
+const regex_position_indicator = / \(\d+:\d+\)$/;
+
 export class Parser {
 	readonly template: string;
 	readonly filename?: string;
@@ -74,10 +76,10 @@ export class Parser {
 
 		if (this.html.children.length) {
 			let start = this.html.children[0].start;
-			while (whitespace.test(template[start])) start += 1;
+			while (regex_whitespace.test(template[start])) start += 1;
 
 			let end = this.html.children[this.html.children.length - 1].end;
-			while (whitespace.test(template[end - 1])) end -= 1;
+			while (regex_whitespace.test(template[end - 1])) end -= 1;
 
 			this.html.start = start;
 			this.html.end = end;
@@ -93,7 +95,7 @@ export class Parser {
 	acorn_error(err: any) {
 		this.error({
 			code: 'parse-error',
-			message: err.message.replace(/ \(\d+:\d+\)$/, '')
+			message: err.message.replace(regex_position_indicator, '')
 		}, err.pos);
 	}
 
@@ -138,7 +140,7 @@ export class Parser {
 	allow_whitespace() {
 		while (
 			this.index < this.template.length &&
-			whitespace.test(this.template[this.index])
+			regex_whitespace.test(this.template[this.index])
 		) {
 			this.index++;
 		}
@@ -200,7 +202,7 @@ export class Parser {
 	}
 
 	require_whitespace() {
-		if (!whitespace.test(this.template[this.index])) {
+		if (!regex_whitespace.test(this.template[this.index])) {
 			this.error({
 				code: 'missing-whitespace',
 				message: 'Expected whitespace'
diff --git a/src/compiler/parse/read/context.ts b/src/compiler/parse/read/context.ts
index 1e97baf8a7..134d11a6ad 100644
--- a/src/compiler/parse/read/context.ts
+++ b/src/compiler/parse/read/context.ts
@@ -10,6 +10,7 @@ import {
 import { parse_expression_at } from '../acorn';
 import { Pattern } from 'estree';
 import parser_errors from '../errors';
+import { regex_not_newline_characters } from '../../utils/patterns';
 
 export default function read_context(
 	parser: Parser
@@ -65,7 +66,7 @@ export default function read_context(
 		// so we offset it by removing 1 character in the `space_with_newline`
 		// to achieve that, we remove the 1st space encountered,
 		// so it will not affect the `column` of the node
-		let space_with_newline = parser.template.slice(0, start).replace(/[^\n]/g, ' ');
+		let space_with_newline = parser.template.slice(0, start).replace(regex_not_newline_characters, ' ');
 		const first_space = space_with_newline.indexOf(' ');
 		space_with_newline = space_with_newline.slice(0, first_space) + space_with_newline.slice(first_space + 1);
 
diff --git a/src/compiler/parse/read/expression.ts b/src/compiler/parse/read/expression.ts
index 5464a950ce..935574440f 100644
--- a/src/compiler/parse/read/expression.ts
+++ b/src/compiler/parse/read/expression.ts
@@ -1,7 +1,7 @@
 import { parse_expression_at } from '../acorn';
 import { Parser } from '../index';
 import { Node } from 'estree';
-import { whitespace } from '../../utils/patterns';
+import { regex_whitespace } from '../../utils/patterns';
 import parser_errors from '../errors';
 
 export default function read_expression(parser: Parser): Node {
@@ -20,7 +20,7 @@ export default function read_expression(parser: Parser): Node {
 
 			if (char === ')') {
 				num_parens -= 1;
-			} else if (!whitespace.test(char)) {
+			} else if (!regex_whitespace.test(char)) {
 				parser.error(parser_errors.unexpected_token(')'), index);
 			}
 
diff --git a/src/compiler/parse/read/script.ts b/src/compiler/parse/read/script.ts
index c9ac4ac344..02506ab3d5 100644
--- a/src/compiler/parse/read/script.ts
+++ b/src/compiler/parse/read/script.ts
@@ -3,6 +3,9 @@ import { Parser } from '../index';
 import { Script } from '../../interfaces';
 import { Node, Program } from 'estree';
 import parser_errors from '../errors';
+import { regex_not_newline_characters } from '../../utils/patterns';
+
+const regex_closing_script_tag = /<\/script\s*>/;
 
 function get_context(parser: Parser, attributes: any[], start: number): string {
 	const context = attributes.find(attribute => attribute.name === 'context');
@@ -23,13 +26,13 @@ function get_context(parser: Parser, attributes: any[], start: number): string {
 
 export default function read_script(parser: Parser, start: number, attributes: Node[]): Script {
 	const script_start = parser.index;
-	const data = parser.read_until(/<\/script\s*>/, parser_errors.unclosed_script);
+	const data = parser.read_until(regex_closing_script_tag, parser_errors.unclosed_script);
 	if (parser.index >= parser.template.length) {
 		parser.error(parser_errors.unclosed_script);
 	}
 
-	const source = parser.template.slice(0, script_start).replace(/[^\n]/g, ' ') + data;
-	parser.read(/<\/script\s*>/);
+	const source = parser.template.slice(0, script_start).replace(regex_not_newline_characters, ' ') + data;
+	parser.read(regex_closing_script_tag);
 
 	let ast: Program;
 
diff --git a/src/compiler/parse/read/style.ts b/src/compiler/parse/read/style.ts
index e4a885a8cc..1e21dddc67 100644
--- a/src/compiler/parse/read/style.ts
+++ b/src/compiler/parse/read/style.ts
@@ -5,10 +5,12 @@ import { Node } from 'estree';
 import { Style } from '../../interfaces';
 import parser_errors from '../errors';
 
+const regex_closing_style_tag = /<\/style\s*>/;
+
 export default function read_style(parser: Parser, start: number, attributes: Node[]): Style {
 	const content_start = parser.index;
 
-	const styles = parser.read_until(/<\/style\s*>/, parser_errors.unclosed_style);
+	const styles = parser.read_until(regex_closing_style_tag, parser_errors.unclosed_style);
 
 	if (parser.index >= parser.template.length) {
 		parser.error(parser_errors.unclosed_style);
@@ -67,7 +69,7 @@ export default function read_style(parser: Parser, start: number, attributes: No
 		}
 	});
 
-	parser.read(/<\/style\s*>/);
+	parser.read(regex_closing_style_tag);
 	const end = parser.index;
 
 	return {
diff --git a/src/compiler/parse/state/mustache.ts b/src/compiler/parse/state/mustache.ts
index da9016a9df..c3b58afe2a 100644
--- a/src/compiler/parse/state/mustache.ts
+++ b/src/compiler/parse/state/mustache.ts
@@ -1,7 +1,7 @@
 import read_context from '../read/context';
 import read_expression from '../read/expression';
 import { closing_tag_omitted } from '../utils/html';
-import { whitespace } from '../../utils/patterns';
+import { regex_whitespace } from '../../utils/patterns';
 import { trim_start, trim_end } from '../../utils/trim';
 import { to_string } from '../utils/node';
 import { Parser } from '../index';
@@ -33,6 +33,8 @@ function trim_whitespace(block: TemplateNode, trim_before: boolean, trim_after:
 	}
 }
 
+const regex_whitespace_with_closing_curly_brace = /\s*}/;
+
 export default function mustache(parser: Parser) {
 	const start = parser.index;
 	parser.index += 1;
@@ -87,8 +89,8 @@ export default function mustache(parser: Parser) {
 		// strip leading/trailing whitespace as necessary
 		const char_before = parser.template[block.start - 1];
 		const char_after = parser.template[parser.index];
-		const trim_before = !char_before || whitespace.test(char_before);
-		const trim_after = !char_after || whitespace.test(char_after);
+		const trim_before = !char_before || regex_whitespace.test(char_before);
+		const trim_after = !char_after || regex_whitespace.test(char_after);
 
 		trim_whitespace(block, trim_before, trim_after);
 
@@ -106,8 +108,8 @@ export default function mustache(parser: Parser) {
 			const block = parser.current();
 			if (block.type !== 'IfBlock') {
 				parser.error(
-					parser.stack.some(block => block.type === 'IfBlock') 
-						? parser_errors.invalid_elseif_placement_unclosed_block(to_string(block)) 
+					parser.stack.some(block => block.type === 'IfBlock')
+						? parser_errors.invalid_elseif_placement_unclosed_block(to_string(block))
 						: parser_errors.invalid_elseif_placement_outside_if
 				);
 			}
@@ -141,8 +143,8 @@ export default function mustache(parser: Parser) {
 			const block = parser.current();
 			if (block.type !== 'IfBlock' && block.type !== 'EachBlock') {
 				parser.error(
-					parser.stack.some(block => block.type === 'IfBlock' || block.type === 'EachBlock') 
-						? parser_errors.invalid_else_placement_unclosed_block(to_string(block)) 
+					parser.stack.some(block => block.type === 'IfBlock' || block.type === 'EachBlock')
+						? parser_errors.invalid_else_placement_unclosed_block(to_string(block))
 						: parser_errors.invalid_else_placement_outside_if
 				);
 			}
@@ -167,15 +169,15 @@ export default function mustache(parser: Parser) {
 			if (block.type !== 'PendingBlock') {
 				parser.error(
 					parser.stack.some(block => block.type === 'PendingBlock')
-						? parser_errors.invalid_then_placement_unclosed_block(to_string(block)) 
-						: parser_errors.invalid_then_placement_without_await 
+						? parser_errors.invalid_then_placement_unclosed_block(to_string(block))
+						: parser_errors.invalid_then_placement_without_await
 				);
 			}
 		} else {
 			if (block.type !== 'ThenBlock' && block.type !== 'PendingBlock') {
 				parser.error(parser.stack.some(block => block.type === 'ThenBlock' || block.type === 'PendingBlock')
-						? parser_errors.invalid_catch_placement_unclosed_block(to_string(block)) 
-						: parser_errors.invalid_catch_placement_without_await 
+					? parser_errors.invalid_catch_placement_unclosed_block(to_string(block))
+					: parser_errors.invalid_catch_placement_without_await
 				);
 			}
 		}
@@ -290,7 +292,7 @@ export default function mustache(parser: Parser) {
 
 		const await_block_shorthand = type === 'AwaitBlock' && parser.eat('then');
 		if (await_block_shorthand) {
-			if (parser.match_regex(/\s*}/)) {
+			if (parser.match_regex(regex_whitespace_with_closing_curly_brace)) {
 				parser.allow_whitespace();
 			} else {
 				parser.require_whitespace();
@@ -301,7 +303,7 @@ export default function mustache(parser: Parser) {
 
 		const await_block_catch_shorthand = !await_block_shorthand && type === 'AwaitBlock' && parser.eat('catch');
 		if (await_block_catch_shorthand) {
-			if (parser.match_regex(/\s*}/)) {
+			if (parser.match_regex(regex_whitespace_with_closing_curly_brace)) {
 				parser.allow_whitespace();
 			} else {
 				parser.require_whitespace();
@@ -350,7 +352,7 @@ export default function mustache(parser: Parser) {
 		let identifiers;
 
 		// Implies {@debug} which indicates "debug all"
-		if (parser.read(/\s*}/)) {
+		if (parser.read(regex_whitespace_with_closing_curly_brace)) {
 			identifiers = [];
 		} else {
 			const expression = read_expression(parser);
diff --git a/src/compiler/parse/state/tag.ts b/src/compiler/parse/state/tag.ts
index 4be47f25b0..bf50c6c774 100644
--- a/src/compiler/parse/state/tag.ts
+++ b/src/compiler/parse/state/tag.ts
@@ -53,13 +53,17 @@ function parent_is_head(stack) {
 	return false;
 }
 
+const regex_closing_textarea_tag = /^<\/textarea(\s[^>]*)?>/i;
+const regex_closing_comment = /-->/;
+const regex_capital_letter = /[A-Z]/;
+
 export default function tag(parser: Parser) {
 	const start = parser.index++;
 
 	let parent = parser.current();
 
 	if (parser.eat('!--')) {
-		const data = parser.read_until(/-->/);
+		const data = parser.read_until(regex_closing_comment);
 		parser.eat('-->', true, parser_errors.unclosed_comment);
 
 		parser.current().children.push({
@@ -104,7 +108,7 @@ export default function tag(parser: Parser) {
 
 	const type = meta_tags.has(name)
 		? meta_tags.get(name)
-		: (/[A-Z]/.test(name[0]) || name === 'svelte:self' || name === 'svelte:component') ? 'InlineComponent'
+		: (regex_capital_letter.test(name[0]) || name === 'svelte:self' || name === 'svelte:component') ? 'InlineComponent'
 			: name === 'svelte:fragment' ? 'SlotTemplate'
 				: name === 'title' && parent_is_head(parser.stack) ? 'Title'
 					: name === 'slot' && !parser.customElement ? 'Slot' : 'Element';
@@ -218,11 +222,10 @@ export default function tag(parser: Parser) {
 		// special case
 		element.children = read_sequence(
 			parser,
-			() =>
-				/^<\/textarea(\s[^>]*)?>/i.test(parser.template.slice(parser.index)),
+			() => regex_closing_textarea_tag.test(parser.template.slice(parser.index)),
 			'inside <textarea>'
 		);
-		parser.read(/^<\/textarea(\s[^>]*)?>/i);
+		parser.read(regex_closing_textarea_tag);
 		element.end = parser.index;
 	} else if (name === 'script' || name === 'style') {
 		// special case
@@ -237,6 +240,8 @@ export default function tag(parser: Parser) {
 	}
 }
 
+const regex_whitespace_or_slash_or_closing_tag = /(\s|\/|>)/;
+
 function read_tag_name(parser: Parser) {
 	const start = parser.index;
 
@@ -266,7 +271,7 @@ function read_tag_name(parser: Parser) {
 
 	if (parser.read(SLOT)) return 'svelte:fragment';
 
-	const name = parser.read_until(/(\s|\/|>)/);
+	const name = parser.read_until(regex_whitespace_or_slash_or_closing_tag);
 
 	if (meta_tags.has(name)) return name;
 
@@ -286,6 +291,10 @@ function read_tag_name(parser: Parser) {
 	return name;
 }
 
+// eslint-disable-next-line no-useless-escape
+const regex_token_ending_character = /[\s=\/>"']/;
+const regex_quote_characters = /["']/;
+
 function read_attribute(parser: Parser, unique_names: Set<string>) {
 	const start = parser.index;
 
@@ -344,8 +353,7 @@ function read_attribute(parser: Parser, unique_names: Set<string>) {
 		}
 	}
 
-	// eslint-disable-next-line no-useless-escape
-	const name = parser.read_until(/[\s=\/>"']/);
+	const name = parser.read_until(regex_token_ending_character);
 	if (!name) return null;
 
 	let end = parser.index;
@@ -360,7 +368,7 @@ function read_attribute(parser: Parser, unique_names: Set<string>) {
 		parser.allow_whitespace();
 		value = read_attribute_value(parser);
 		end = parser.index;
-	} else if (parser.match_regex(/["']/)) {
+	} else if (parser.match_regex(regex_quote_characters)) {
 		parser.error(parser_errors.unexpected_token('='), parser.index);
 	}
 
diff --git a/src/compiler/preprocess/index.ts b/src/compiler/preprocess/index.ts
index ab2ede29e0..45885afa96 100644
--- a/src/compiler/preprocess/index.ts
+++ b/src/compiler/preprocess/index.ts
@@ -4,6 +4,7 @@ import { MappedCode, SourceLocation, parse_attached_sourcemap, sourcemap_add_off
 import { decode_map } from './decode_sourcemap';
 import { replace_in_code, slice_source } from './replace_in_code';
 import { MarkupPreprocessor, Source, Preprocessor, PreprocessorGroup, Processed } from './types';
+import { regex_whitespaces } from '../utils/patterns';
 
 export * from './types';
 
@@ -13,8 +14,10 @@ interface SourceUpdate {
 	dependencies?: string[];
 }
 
+const regex_filepath_separator = /[/\\]/;
+
 function get_file_basename(filename: string) {
-	return filename.split(/[/\\]/).pop();
+	return filename.split(regex_filepath_separator).pop();
 }
 
 /**
@@ -120,20 +123,26 @@ function processed_tag_to_code(
 	return tag_open_code.concat(content_code).concat(tag_close_code);
 }
 
+const regex_quoted_value = /^['"](.*)['"]$/;
+
 function parse_tag_attributes(str: string) {
 	// note: won't work with attribute values containing spaces.
 	return str
-		.split(/\s+/)
+		.split(regex_whitespaces)
 		.filter(Boolean)
 		.reduce((attrs, attr) => {
 			const i = attr.indexOf('=');
 			const [key, value] = i > 0 ? [attr.slice(0, i), attr.slice(i + 1)] : [attr];
-			const [, unquoted] = (value && value.match(/^['"](.*)['"]$/)) || [];
+			const [, unquoted] = (value && value.match(regex_quoted_value)) || [];
 
 			return { ...attrs, [key]: unquoted ?? value ?? true };
 		}, {});
 }
 
+
+const regex_style_tags = /<!--[^]*?-->|<style(\s[^]*?)?(?:>([^]*?)<\/style>|\/>)/gi;
+const regex_script_tags = /<!--[^]*?-->|<script(\s[^]*?)?(?:>([^]*?)<\/script>|\/>)/gi;
+
 /**
  * Calculate the updates required to process all instances of the specified tag.
  */
@@ -143,10 +152,7 @@ async function process_tag(
 	source: Source
 ): Promise<SourceUpdate> {
 	const { filename, source: markup } = source;
-	const tag_regex =
-		tag_name === 'style'
-			? /<!--[^]*?-->|<style(\s[^]*?)?(?:>([^]*?)<\/style>|\/>)/gi
-			: /<!--[^]*?-->|<script(\s[^]*?)?(?:>([^]*?)<\/script>|\/>)/gi;
+	const tag_regex = tag_name === 'style' ? regex_style_tags : regex_script_tags;
 
 	const dependencies: string[] = [];
 
@@ -190,7 +196,7 @@ async function process_markup(process: MarkupPreprocessor, source: Source) {
 			string: processed.code,
 			map: processed.map
 				? // TODO: can we use decode_sourcemap?
-				  typeof processed.map === 'string'
+				typeof processed.map === 'string'
 					? JSON.parse(processed.map)
 					: processed.map
 				: undefined,
diff --git a/src/compiler/utils/extract_svelte_ignore.ts b/src/compiler/utils/extract_svelte_ignore.ts
index 306ba872d6..30be2893a4 100644
--- a/src/compiler/utils/extract_svelte_ignore.ts
+++ b/src/compiler/utils/extract_svelte_ignore.ts
@@ -1,11 +1,12 @@
 import { TemplateNode } from '../interfaces';
 import { flatten } from './flatten';
+import { regex_whitespace } from './patterns';
 
-const pattern = /^\s*svelte-ignore\s+([\s\S]+)\s*$/m;
+const regex_svelte_ignore = /^\s*svelte-ignore\s+([\s\S]+)\s*$/m;
 
 export function extract_svelte_ignore(text: string): string[] {
-	const match = pattern.exec(text);
-	return match ? match[1].split(/[^\S]/).map(x => x.trim()).filter(Boolean) : [];
+	const match = regex_svelte_ignore.exec(text);
+	return match ? match[1].split(regex_whitespace).map(x => x.trim()).filter(Boolean) : [];
 }
 
 export function extract_svelte_ignore_from_comments<Node extends { leadingComments?: Array<{value: string}> }>(node: Node): string[] {
diff --git a/src/compiler/utils/get_code_frame.ts b/src/compiler/utils/get_code_frame.ts
index 1097f5b3d2..14ca44badb 100644
--- a/src/compiler/utils/get_code_frame.ts
+++ b/src/compiler/utils/get_code_frame.ts
@@ -1,5 +1,7 @@
+const regex_tabs = /^\t+/;
+
 function tabs_to_spaces(str: string) {
-	return str.replace(/^\t+/, match => match.split('\t').join('  '));
+	return str.replace(regex_tabs, match => match.split('\t').join('  '));
 }
 
 export default function get_code_frame(
diff --git a/src/compiler/utils/mapped_code.ts b/src/compiler/utils/mapped_code.ts
index 04fa05be9a..bf7b016fc5 100644
--- a/src/compiler/utils/mapped_code.ts
+++ b/src/compiler/utils/mapped_code.ts
@@ -61,6 +61,8 @@ function merge_tables<T>(this_table: T[], other_table: T[]): [T[], number[], boo
 	return [new_table, idx_map, val_changed, idx_changed];
 }
 
+const regex_line_token = /([^\d\w\s]|\s+)/g;
+
 export class MappedCode {
 	string: string;
 	map: DecodedSourceMap;
@@ -195,7 +197,7 @@ export class MappedCode {
 		const line_list = source.split('\n');
 		for (let line = 0; line < line_list.length; line++) {
 			map.mappings.push([]);
-			const token_list = line_list[line].split(/([^\d\w\s]|\s+)/g);
+			const token_list = line_list[line].split(regex_line_token);
 			for (let token = 0, column = 0; token < token_list.length; token++) {
 				if (token_list[token] == '') continue;
 				map.mappings[line].push([column, 0, offset.line + line, column]);
@@ -245,7 +247,7 @@ export function combine_sourcemaps(
 	if (!map.file) delete map.file; // skip optional field `file`
 
 	// When source maps are combined and the leading map is empty, sources is not set.
-	// Add the filename to the empty array in this case. 
+	// Add the filename to the empty array in this case.
 	// Further improvements to remapping may help address this as well https://github.com/ampproject/remapping/issues/116
 	if (!map.sources.length) map.sources = [filename];
 
@@ -289,6 +291,8 @@ export function apply_preprocessor_sourcemap(filename: string, svelte_map: Sourc
 	return result_map as SourceMap;
 }
 
+const regex_data_uri = /data:(?:application|text)\/json;(?:charset[:=]\S+?;)?base64,(\S*)/;
+
 // parse attached sourcemap in processed.code
 export function parse_attached_sourcemap(processed: Processed, tag_name: 'script' | 'style'): void {
 	const r_in = '[#@]\\s*sourceMappingURL\\s*=\\s*(\\S*)';
@@ -302,7 +306,7 @@ export function parse_attached_sourcemap(processed: Processed, tag_name: 'script
 	}
 	processed.code = processed.code.replace(regex, (_, match1, match2) => {
 		const map_url = (tag_name == 'script') ? (match1 || match2) : match1;
-		const map_data = (map_url.match(/data:(?:application|text)\/json;(?:charset[:=]\S+?;)?base64,(\S*)/) || [])[1];
+		const map_data = (map_url.match(regex_data_uri) || [])[1];
 		if (map_data) {
 			// sourceMappingURL is data URL
 			if (processed.map) {
diff --git a/src/compiler/utils/names.ts b/src/compiler/utils/names.ts
index 9d5b78fceb..303c6297b0 100644
--- a/src/compiler/utils/names.ts
+++ b/src/compiler/utils/names.ts
@@ -1,5 +1,6 @@
 import { isIdentifierStart, isIdentifierChar } from 'acorn';
 import full_char_code_at from './full_char_code_at';
+import { regex_starts_with_underscore, regex_ends_with_underscore } from './patterns';
 
 export const reserved = new Set([
 	'arguments',
@@ -65,10 +66,13 @@ export function is_valid(str: string): boolean {
 	return true;
 }
 
+const regex_non_standard_characters = /[^a-zA-Z0-9_]+/g;
+const regex_starts_with_number = /^[0-9]/;
+
 export function sanitize(name: string) {
 	return name
-		.replace(/[^a-zA-Z0-9_]+/g, '_')
-		.replace(/^_/, '')
-		.replace(/_$/, '')
-		.replace(/^[0-9]/, '_$&');
+		.replace(regex_non_standard_characters, '_')
+		.replace(regex_starts_with_underscore, '')
+		.replace(regex_ends_with_underscore, '')
+		.replace(regex_starts_with_number, '_$&');
 }
diff --git a/src/compiler/utils/patterns.ts b/src/compiler/utils/patterns.ts
index 071abd791f..9429d47227 100644
--- a/src/compiler/utils/patterns.ts
+++ b/src/compiler/utils/patterns.ts
@@ -1,6 +1,24 @@
-export const whitespace = /[ \t\r\n]/;
-export const start_whitespace = /^[ \t\r\n]*/;
-export const end_whitespace = /[ \t\r\n]*$/;
-export const start_newline = /^\r?\n/;
+export const regex_whitespace = /\s/;
+export const regex_whitespaces = /\s+/;
+export const regex_starts_with_whitespace = /^\s/;
+export const regex_starts_with_whitespaces = /^[ \t\r\n]*/;
+export const regex_ends_with_whitespace = /\s$/;
+export const regex_ends_with_whitespaces = /[ \t\r\n]*$/;
+export const regex_only_whitespaces = /^\s+$/;
 
-export const dimensions = /^(?:offset|client)(?:Width|Height)$/;
+export const regex_whitespace_characters = /\s/g;
+export const regex_non_whitespace_character = /\S/;
+
+export const regex_starts_with_newline = /^\r?\n/;
+export const regex_not_newline_characters = /[^\n]/g;
+
+export const regex_double_quotes = /"/g;
+
+export const regex_backslashes = /\\/g;
+
+export const regex_starts_with_underscore = /^_/;
+export const regex_ends_with_underscore = /_$/;
+
+export const regex_invalid_variable_identifier_characters = /[^a-zA-Z0-9_$]/g;
+
+export const regex_dimensions = /^(?:offset|client)(?:Width|Height)$/;
diff --git a/src/compiler/utils/trim.ts b/src/compiler/utils/trim.ts
index 05af79cc90..919a423d7f 100644
--- a/src/compiler/utils/trim.ts
+++ b/src/compiler/utils/trim.ts
@@ -1,9 +1,9 @@
-import { start_whitespace, end_whitespace } from './patterns';
+import { regex_starts_with_whitespaces, regex_ends_with_whitespaces } from './patterns';
 
 export function trim_start(str: string) {
-	return str.replace(start_whitespace, '');
+	return str.replace(regex_starts_with_whitespaces, '');
 }
 
 export function trim_end(str: string) {
-	return str.replace(end_whitespace, '');
+	return str.replace(regex_ends_with_whitespaces, '');
 }