generate-regex.js

import { promises as fs } from 'node:fs'
import regenerate from 'regenerate'
// @ts-expect-error: untyped
import alphabetics from '@unicode/unicode-13.0.0/Binary_Property/Alphabetic/code-points.js'

const categoryBase = new URL('../node_modules/@unicode/unicode-13.0.0/General_Category/', import.meta.url)

// Unicode General Categories to remove.
const ranges = [
  // Some numbers:
  'Other_Number',

  // Some punctuation:
  'Close_Punctuation',
  'Final_Punctuation',
  'Initial_Punctuation',
  'Open_Punctuation',
  'Other_Punctuation',
  // All except a normal `-` (dash)
  'Dash_Punctuation',

  // All:
  'Symbol',
  'Control',
  'Private_Use',
  'Format',
  'Unassigned',

  // All except a normal ` ` (space)
  'Separator'
]

const generator = regenerate()

let index = -1

// Add code points to strip.
while (++index < ranges.length) {
  const name = ranges[index]
  /** @type {{default: Array<number>}} */
  const { default: codePoints } = await import(new URL(name + '/code-points.js', categoryBase).href)

  generator.add(codePoints)
}

generator
  // Some overlap between letters and Other Symbol.
  .remove(alphabetics)
  // Spaces are turned to `-`
  .remove(' ')
  // Dash is kept.
  .remove('-')

await fs.writeFile('regex.js', [
  '// This module is generated by `script/`.',
  '/* eslint-disable no-control-regex, no-misleading-character-class, no-useless-escape */',
  'export const regex = ' + generator.toRegExp() + 'g',
  ''
].join('\n'))