index.js

const log2 = Math.log2 || (n => Math.log(n) / Math.LN2);
const bits = (n) => ((log2(n) + 1) | 0);

const buildUnicodeProperties = (data, trie) => {
  // compute the number of bits stored for each field
  const CATEGORY_BITS = bits(data.categories.length - 1);
  const COMBINING_BITS = bits(data.combiningClasses.length - 1);
  const SCRIPT_BITS = bits(data.scripts.length - 1);
  const EAW_BITS = bits(data.eaw.length - 1);
  const NUMBER_BITS = 10;

  // compute shift and mask values for each field
  const CATEGORY_SHIFT = COMBINING_BITS + SCRIPT_BITS + EAW_BITS + NUMBER_BITS;
  const COMBINING_SHIFT = SCRIPT_BITS + EAW_BITS + NUMBER_BITS;
  const SCRIPT_SHIFT = EAW_BITS + NUMBER_BITS;
  const EAW_SHIFT = NUMBER_BITS;
  const CATEGORY_MASK = (1 << CATEGORY_BITS) - 1;
  const COMBINING_MASK = (1 << COMBINING_BITS) - 1;
  const SCRIPT_MASK = (1 << SCRIPT_BITS) - 1;
  const EAW_MASK = (1 << EAW_BITS) - 1;
  const NUMBER_MASK = (1 << NUMBER_BITS) - 1;

  const getCategory = (codePoint) => {
    const val = trie.get(codePoint);
    return data.categories[(val >> CATEGORY_SHIFT) & CATEGORY_MASK];
  };

  const getCombiningClass = (codePoint) => {
    const val = trie.get(codePoint);
    return data.combiningClasses[(val >> COMBINING_SHIFT) & COMBINING_MASK];
  };

  const getScript = (codePoint) => {
    const val = trie.get(codePoint);
    return data.scripts[(val >> SCRIPT_SHIFT) & SCRIPT_MASK];
  };

  const getEastAsianWidth = (codePoint) => {
    const val = trie.get(codePoint);
    return data.eaw[(val >> EAW_SHIFT) & EAW_MASK];
  };

  const getNumericValue = (codePoint) => {
    let val = trie.get(codePoint);
    let num = val & NUMBER_MASK;

    if (num === 0) {
      return null;
    } else if (num <= 50) {
      return num - 1;
    } else if (num < 0x1e0) {
      const numerator = (num >> 4) - 12;
      const denominator = (num & 0xf) + 1;
      return numerator / denominator;
    } else if (num < 0x300) {
      val = (num >> 5) - 14;
      let exp = (num & 0x1f) + 2;

      while (exp > 0) {
        val *= 10;
        exp--;
      }
      return val;
    } else {
      val = (num >> 2) - 0xbf;
      let exp = (num & 3) + 1;
      while (exp > 0) {
        val *= 60;
        exp--;
      }
      return val;
    }
  };

  const isAlphabetic = (codePoint) => {
    const category = getCategory(codePoint);
    return (
      category === 'Lu' ||
      category === 'Ll' ||
      category === 'Lt' ||
      category === 'Lm' ||
      category === 'Lo' ||
      category === 'Nl'
    )
  };

  const isDigit = (codePoint) => (
    getCategory(codePoint) === 'Nd'
  );

  const isPunctuation = (codePoint) => {
    const category = getCategory(codePoint);
    return (
      category === 'Pc' ||
      category === 'Pd' ||
      category === 'Pe' ||
      category === 'Pf' ||
      category === 'Pi' ||
      category === 'Po' ||
      category === 'Ps'
    );
  };

  const isLowerCase = (codePoint) => {
    return getCategory(codePoint) === 'Ll';
  };

  const isUpperCase = (codePoint) => (
    getCategory(codePoint) === 'Lu'
  );

  const isTitleCase = (codePoint) => (
    getCategory(codePoint) === 'Lt'
  );

  const isWhiteSpace = (codePoint) => {
    const category = getCategory(codePoint);
    return (
      category === 'Zs' ||
      category === 'Zl' ||
      category === 'Zp'
    );
  };

  const isBaseForm = (codePoint) => {
    const category = getCategory(codePoint);
    return (
      category === 'Nd' ||
      category === 'No' ||
      category === 'Nl' ||
      category === 'Lu' ||
      category === 'Ll' ||
      category === 'Lt' ||
      category === 'Lm' ||
      category === 'Lo' ||
      category === 'Me' ||
      category === 'Mc'
    )
  };

  const isMark = (codePoint) => {
    const category = getCategory(codePoint);
    return (
      category === 'Mn' ||
      category === 'Me' ||
      category === 'Mc'
    );
  };

  return {
    getCategory,
    getCombiningClass,
    getScript,
    getEastAsianWidth,
    getNumericValue,
    isAlphabetic,
    isDigit,
    isPunctuation,
    isLowerCase,
    isUpperCase,
    isTitleCase,
    isWhiteSpace,
    isBaseForm,
    isMark
  }
}

export default buildUnicodeProperties;