genLineBreak.js

#!/usr/bin/env node

import {UnicodeTrieBuilder} from '../builder.js';
import fs from 'node:fs/promises';

// Cache linebreak data in local file.  Requires Node v18+.
const INPUT = 'LineBreak.txt';
let txt = null;
try {
  txt = await fs.readFile(INPUT, 'utf8');
} catch (ignore) {
  // Only used in tooling, on modern node
  const res = await fetch('https://www.unicode.org/Public/UCD/latest/ucd/LineBreak.txt');
  txt = await res.text();
  fs.writeFile(INPUT, txt, 'utf8');
}

// Default value is "XX".  Add a new property value "ER" for errors.
const t = new UnicodeTrieBuilder('XX', 'ER');

// Set defaults
t.setRange(0x20000, 0x2FFFD, 'ID');
t.setRange(0x30000, 0x3FFFD, 'ID');
t.setRange(0x1F000, 0x1FAFF, 'ID');
t.setRange(0x1FC00, 0x1FFFD, 'ID');
t.setRange(0x20A0, 0x20CF, 'PR');

let ranges = 0;
let single = 0;
let total = 0;
for (const line of txt.split('\n')) {
  // The format is two fields separated by a semicolon.
  // Field 0: Unicode code point value or range of code point values
  // Field 1: Line_Break property, a two-character string
  const m = line.match(/^([0-9A-F]{4,6})(?:\.\.([0-9A-F]{4,6}))?\s*;\s*(\S+)/i);
  if (m) {
    if (m[2]) {
      const start = parseInt(m[1], 16);
      const end = parseInt(m[2], 16);
      t.setRange(start, end, m[3]);
      ranges++;
      total += (end - start + 1);
    } else {
      t.set(parseInt(m[1], 16), m[3]);
      single++;
      total++;
    }
  }
}

await fs.writeFile('lineBreak.js', t.toModule({name: 'LineBreak', pkg: '../index.js', quot: "'"}));

// eslint-disable-next-line no-console
console.log(`Ranges: ${ranges}\nSingle: ${single}\nTotal: ${total}`);