svelte
Version:
Cybernetically enhanced web apps
94 lines (79 loc) • 2.41 kB
JavaScript
/** @import { Expression } from 'estree' */
/** @import { Parser } from '../index.js' */
import { parse_expression_at } from '../acorn.js';
import { regex_whitespace } from '../../patterns.js';
import * as e from '../../../errors.js';
import { find_matching_bracket } from '../utils/bracket.js';
/**
* @param {Parser} parser
* @param {string} [opening_token]
* @returns {Expression | undefined}
*/
export function get_loose_identifier(parser, opening_token) {
// Find the next } and treat it as the end of the expression
const end = find_matching_bracket(parser.template, parser.index, opening_token ?? '{');
if (end) {
const start = parser.index;
parser.index = end;
// We don't know what the expression is and signal this by returning an empty identifier
return {
type: 'Identifier',
start,
end,
name: ''
};
}
}
/**
* @param {Parser} parser
* @param {string} [opening_token]
* @param {boolean} [disallow_loose]
* @returns {Expression}
*/
export default function read_expression(parser, opening_token, disallow_loose) {
try {
let comment_index = parser.root.comments.length;
const node = parse_expression_at(
parser.template,
parser.root.comments,
parser.ts,
parser.index
);
let num_parens = 0;
let i = parser.root.comments.length;
while (i-- > comment_index) {
const comment = parser.root.comments[i];
if (comment.end < node.start) {
parser.index = comment.end;
break;
}
}
for (let i = parser.index; i < /** @type {number} */ (node.start); i += 1) {
if (parser.template[i] === '(') num_parens += 1;
}
let index = /** @type {number} */ (node.end);
const last_comment = parser.root.comments.at(-1);
if (last_comment && last_comment.end > index) index = last_comment.end;
while (num_parens > 0) {
const char = parser.template[index];
if (char === ')') {
num_parens -= 1;
} else if (!regex_whitespace.test(char)) {
e.expected_token(index, ')');
}
index += 1;
}
parser.index = index;
return /** @type {Expression} */ (node);
} catch (err) {
// If we are in an each loop we need the error to be thrown in cases like
// `as { y = z }` so we still throw and handle the error there
if (parser.loose && !disallow_loose) {
const expression = get_loose_identifier(parser, opening_token);
if (expression) {
return expression;
}
}
parser.acorn_error(err);
}
}