parse-bidi-brackets.js

'use strict';

const regenerate = require('regenerate');
const utils = require('./utils.js');

const bidiBracketMap = new Map([
	['o', 'Open'],
	['c', 'Close'],
	['n', 'None']
]);

const parseBidiBrackets = function(version) {
	const map = {
		'Open': regenerate(),
		'Close': regenerate(),
		'None': regenerate().addRange(0, 0x10FFFF)
	};
	const source = utils.readDataFile(version, 'bidi-brackets');
	if (!source) {
		return;
	}
	const lines = source.split('\n');
	for (const line of lines) {
		if (
			/^#/.test(line) ||
			!/;\x20/.test(line)
		) {
			continue;
		}
		const data = line.trim().split(';');
		const charRange = data[0].replace('..', '-').trim();
		let item = data[2].split('#')[0].trim();
		item = bidiBracketMap.get(item);
		const rangeParts = charRange.split('-');
		if (rangeParts.length == 2) {
			const [from, to] = [
				parseInt(rangeParts[0], 16),
				parseInt(rangeParts[1], 16),
			];
			map['None'].removeRange(from, to);
			map[item].addRange(from, to);
		} else {
			const codePoint = parseInt(charRange, 16);
			map['None'].remove(codePoint);
			map[item].add(codePoint);
		}
	}

	return map;
};

module.exports = parseBidiBrackets;