one parser call: js.parse(entry, offset, { end, stopAt }) replaces the five parse-at methods, the answer is kept whole for its tables, and a scope's bindings are grouped here

packages/svelte/src/compiler/phases/1-parse/js.js

@@ -13,36 +13,23 @@ import { keep_tables } from '../../utils/ast.js';
  * @returns {Program}
  */
 export function parse(source, comments, typescript) {
-	let ast;
+	let answer;
 	try {
-		ast = teasel.parse(source, {
+		answer = new teasel.Source(source, {
 			sourceType: 'module',
 			typescript,
 			comments: true,
 			locations: true,
 			scopes: true
-		});
+		}).parse();
 	} catch (err) {
 		return handle_parse_error(err);
 	}
 
-	add_comments(source, comments, /** @type {teasel.Comment[]} */ (ast.comments));
-	delete ast.comments;
-	keep_tables(ast, tables(ast));
-
-	return ast;
-}
+	add_comments(source, comments, /** @type {teasel.Comment[]} */ (answer.comments));
+	keep_tables(answer.node, answer);
 
-/**
- * Takes the tables off an answer, so they reach the scope analysis without showing in the tree.
- * @param {{ scopes?: any; bindings?: any; references?: any }} answer
- */
-function tables(answer) {
-	const { scopes, bindings, references } = answer;
-	delete answer.scopes;
-	delete answer.bindings;
-	delete answer.references;
-	return { scopes, bindings, references };
+	return answer.node;
 }
 
 /**
@@ -53,9 +40,9 @@ function tables(answer) {
  * @returns {Program}
  */
 export function parse_script(parser, start, end) {
-	let ast;
+	let answer;
 	try {
-		ast = parser.js.parse(start, end);
+		answer = parser.js.parse('program', start, { end });
 	} catch (err) {
 		return handle_parse_error(err);
 	}
@@ -63,15 +50,12 @@ export function parse_script(parser, start, end) {
 	add_comments(
 		parser.template,
 		parser.root.comments,
-		/** @type {teasel.Comment[]} */ (ast.comments)
+		/** @type {teasel.Comment[]} */ (answer.comments)
 	);
-	delete ast.comments;
-	delete ast.errors;
-	keep_tables(ast, tables(ast));
-	unsupported(ast.typescript);
-	delete ast.typescript;
+	keep_tables(answer.node, answer);
+	unsupported(answer.typescript);
 
-	return ast;
+	return answer.node;
 }
 
 /**
@@ -109,8 +93,8 @@ function read(parser, run) {
  */
 export function read_expression(parser, stop_at) {
 	const start = parser.index;
-	const answer = read(parser, (js) => js.parseExpressionAt(start, stop_at));
-	keep_tables(answer.node, tables(answer));
+	const answer = read(parser, (js) => js.parse('expression', start, { stopAt: stop_at }));
+	keep_tables(answer.node, answer);
 	const node = answer.node;
 	// the language tools copy an expression's text by its node's range, so the placeholder standing for one that could not be read spans what was read
 	if (node.type === 'Identifier' && node.name === '' && node.start === node.end) {
@@ -146,8 +130,8 @@ export function read_pattern(parser) {
 		}
 	}
 
-	const answer = read(parser, (js) => js.parsePatternAt(start));
-	keep_tables(answer.node, tables(answer));
+	const answer = read(parser, (js) => js.parse('pattern', start));
+	keep_tables(answer.node, answer);
 	return answer.node;
 }
 
@@ -157,9 +141,9 @@ export function read_pattern(parser) {
  */
 export function read_params(parser) {
 	const start = parser.index;
-	const answer = read(parser, (js) => js.parseParamsAt(start));
-	keep_tables(answer.params, tables(answer));
-	return answer.params;
+	const answer = read(parser, (js) => js.parse('params', start));
+	keep_tables(answer.node, answer);
+	return answer.node;
 }
 
 /**
@@ -167,7 +151,7 @@ export function read_params(parser) {
  */
 export function read_type_parameters(parser) {
 	const start = parser.index;
-	read(parser, (js) => js.parseTypeParametersAt(start));
+	read(parser, (js) => js.parse('typeParameters', start));
 }
 
 /**
@@ -177,8 +161,8 @@ export function read_type_parameters(parser) {
 export function read_statement(parser) {
 	const start = parser.index;
 
-	const answer = read(parser, (js) => js.parseStatementAt(start));
-	keep_tables(answer.node, tables(answer));
+	const answer = read(parser, (js) => js.parse('statement', start));
+	keep_tables(answer.node, answer);
 	return answer.node;
 }
 

packages/svelte/src/compiler/phases/1-parse/state/tag.js

@@ -174,7 +174,7 @@ function open(parser) {
 		if (parser.eat('(')) {
 			parser.allow_whitespace();
 
-			key = read_expression(parser, undefined, '(');
+			key = read_expression(parser);
 			parser.allow_whitespace();
 			parser.eat(')', true);
 			parser.allow_whitespace();

packages/svelte/src/compiler/phases/scope.js

@@ -1004,14 +1004,14 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 	const from_parser = new Map();
 
 	/**
-	 * Declares in `scope` what the parser found declared in `parsed`: its parameters, or the rest.
+	 * Declares in `scope` what the parser found declared in one of its scopes: the parameters, or the rest.
 	 * @param {Scope} scope
-	 * @param {import('@teasel/parser').Scope} parsed
+	 * @param {import('@teasel/parser').Binding[]} bindings
 	 * @param {boolean} params
 	 * @param {boolean} [template] the declarations are a const tag's
 	 */
-	function declare_parsed(scope, parsed, params, template = false) {
-		for (const binding of parsed.bindings) {
+	function declare_parsed(scope, bindings, params, template = false) {
+		for (const binding of bindings) {
 			if ((binding.kind === 'param') !== params) continue;
 			// no node: `arguments`, or a declaration erased with the TypeScript it belonged to
 			if (binding.node === null || binding.kind === 'class-name' || binding.kind === 'pattern')
@@ -1086,6 +1086,15 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 			}
 			return;
 		}
+		/** @type {Map<import('@teasel/parser').Scope, import('@teasel/parser').Binding[]>} the answer's bindings by the scope that holds them */
+		const by_scope = new Map();
+		for (const binding of answer.bindings) {
+			const held = by_scope.get(binding.scope);
+			if (held === undefined) by_scope.set(binding.scope, [binding]);
+			else held.push(binding);
+		}
+		/** @param {import('@teasel/parser').Scope} parsed */
+		const of = (parsed) => by_scope.get(parsed) ?? [];
 		/** @type {Map<import('@teasel/parser').Scope, Scope>} the parser's scopes and ours; a function's holds its parameters */
 		const ours = new Map([[outermost, scope]]);
 		/** @type {Map<import('@teasel/parser').Scope, Scope>} a function's body, which holds the rest */
@@ -1108,7 +1117,7 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 			return /** @type {Scope} */ (ours.get(scope));
 		}
 
-		declare_parsed(scope, outermost, false, template);
+		declare_parsed(scope, of(outermost), false, template);
 
 		for (let i = 1; i < answer.scopes.length; i++) {
 			const parsed = answer.scopes[i];
@@ -1124,18 +1133,18 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 					scopes.set(node, params);
 					ours.set(parsed, params);
 					if (parsed.parent?.kind === 'function-name') ours.set(parsed.parent, params);
-					declare_parsed(params, parsed, true);
+					declare_parsed(params, of(parsed), true);
 					if (
 						node.body.type !== 'BlockStatement' ||
 						(node.type === 'FunctionExpression' && node.id)
 					) {
-						declare_parsed(params, parsed, false);
+						declare_parsed(params, of(parsed), false);
 					}
 					if (node.body.type === 'BlockStatement') {
 						const body = params.child();
 						scopes.set(node.body, body);
 						bodies.set(parsed, body);
-						declare_parsed(body, parsed, false);
+						declare_parsed(body, of(parsed), false);
 					}
 					break;
 				}
@@ -1147,7 +1156,7 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 					const inside = parent.child(true);
 					scopes.set(node, inside);
 					ours.set(parsed, inside);
-					declare_parsed(inside, parsed, false);
+					declare_parsed(inside, of(parsed), false);
 					break;
 				}
 				default:

packages/svelte/src/compiler/utils/ast.js

@@ -4,21 +4,21 @@ import { walk } from 'zimmerframe';
 import { bindingOf } from '@teasel/parser';
 
 /**
- * @typedef {{ scopes: import('@teasel/parser').Scope[]; bindings: import('@teasel/parser').Binding[]; references: import('@teasel/parser').Reference[] }} Tables
- * the parser's scope, binding and reference tables for one answer
+ * @typedef {Required<Pick<import('@teasel/parser').Parsed<unknown>, 'scopes' | 'bindings' | 'references'>>} Tables
+ * the parser's scope, binding and reference tables for one answer, parsed with `scopes`
  */
 
 // a symbol on the root: a property load where the walk asks every node, not a map lookup
 const PARSED = Symbol('parsed');
 
 /**
- * Keeps the parser's tables on the root it parsed, a script's program or a template's
- * expression, pattern, parameter list or declaration.
+ * Keeps the parser's answer on the root it parsed, a script's program or a template's
+ * expression, pattern, parameter list or declaration, for its tables.
  * @param {object} root
- * @param {Tables} tables
+ * @param {import('@teasel/parser').Parsed<unknown>} answer
  */
-export function keep_tables(root, tables) {
-	/** @type {any} */ (root)[PARSED] = tables;
+export function keep_tables(root, answer) {
+	/** @type {any} */ (root)[PARSED] = answer;
 }
 
 /**