@sutton-signwriting/unicode8/convert/convert.mjs

/**
* Sutton SignWriting Unicode 8 Module v1.2.0 (https://github.com/sutton-signwriting/unicode8)
* Author: Steve Slevinski  (https://SteveSlevinski.me)
* Sponsor: https://patreon.com/signwriting
* Donate: https://donate.sutton-signwriting.io
*
* convert.mjs is released under the MIT License.
*/

/**
 * Object of regular expressions for symbol strings
 * 
 *   { base, fill, rotation, full }
 * @alias symbol.re
 * @type {object}
 */
let re = {
  'base': '(?:\uD836[\uDC00-\uDE8B])',
  'fill': '(?:\uD836[\uDE9B-\uDE9F])',
  'rotation': '(?:\uD836[\uDEA1-\uDEAF])'
};
re.full = `(${re.base})(${re.fill})?(${re.rotation})?`;

/**
 * Function to parse symbol string to object
 * @function symbol.parse
 * @param {string} symbolString - a symbol string
 * @returns {object} elements of symbol string
 * @example
 * symbol.parse('𝠀')
 * 
 * return {
 *  'base': '𝠀',
 *  'fill': undefined,
 *  'rotation': undefined
 * }
 */
const parse = symbolString => {
  const regex = `^${re.full}`;
  const m = (typeof symbolString === 'string' ? symbolString.match(new RegExp(regex)) : []) || [];
  return {
    'base': !m[1] ? undefined : m[1],
    'fill': !m[2] ? undefined : m[2],
    'rotation': !m[3] ? undefined : m[3]
  };
};

/** The convert module contains functions to help process the various SignWriting Character sets. 
 * @module convert
 */

/**
* Function to convert a SignWriting in Unicode 8 (uni8) code point to a character
* @function convert.code2uni
* @param {integer} code - unicode code point
* @returns {string} SignWriting in Unicode 8 character
* @example
* convert.code2uni(0x1D800)
* 
* return '𝠀'
*/
const code2uni = code => String.fromCharCode(0xD800 + (code - 0x10000 >> 10), 0xDC00 + (code - 0x10000 & 0x3FF));

/**
* Function to convert a SignWriting in Unicode 8 (uni8) character to a code point
* @function convert.uni2code
* @param {string} uni8 - SignWriting in Unicode 8 character
* @returns {integer} unicode code point
* @example
* convert.uni2code('𝠀')
* 
* return 0x1D800
*/
const uni2code = uni8 => uni8.codePointAt(0);

/**
* Function to convert a SignWriting in Unicode 8 (uni8) character to hex values
* @function convert.uni2hex
* @param {string} uni8 - SignWriting in Unicode 8 character
* @returns {string} hex value of unicode character
* @example
* convert.uni2hex('𝠀')
* 
* return "1D800"
*/
const uni2hex = uni8 => uni8.codePointAt(0).toString(16).toUpperCase();

/**
* Function to convert a SignWriting in Unicode 8 (uni8) symbol to Formal SignWriting in ASCII (FSW)
* @function convert.uni2fsw
* @param {string} uni8 - SignWriting in Unicode 8 character(s)
* @returns {string} an FSW symbol key
* @example
* convert.uni2fsw('𝠀')
* 
* return 'S10000'
*/
const uni2fsw = uni8 => {
  let sym = parse(uni8);
  if (sym.base) {
    sym.base = sym.base.codePointAt(0) - 0x1D700;
    sym.fill = sym.fill ? sym.fill.codePointAt(0) - 0x1DA9A : 0;
    sym.rotation = sym.rotation ? sym.rotation.codePointAt(0) - 0x1DAA0 : 0;
    return "S" + sym.base.toString(16) + sym.fill.toString(16) + sym.rotation.toString(16);
  } else {
    return undefined;
  }
};

/**
* Function to convert a SignWriting in Unicode 8 (uni8) symbol to SignWriting in Unicode (SWU)
* @function convert.uni2swu
* @param {string} uni8 - SignWriting in Unicode 8 character(s)
* @returns {string} an SWU symbol
* @example
* convert.uni2swu('𝠀')
* 
* return '񀀁'
*/
const uni2swu = uni8 => {
  let sym = parse(uni8);
  if (sym.base) {
    sym.base = sym.base.codePointAt(0) - 0x1D800;
    sym.fill = sym.fill ? sym.fill.codePointAt(0) - 0x1DA9A : 0;
    sym.rotation = sym.rotation ? sym.rotation.codePointAt(0) - 0x1DAA0 : 0;
    return code2uni(0x40001 + sym.base * 96 + sym.fill * 16 + sym.rotation);
  } else {
    return undefined;
  }
};

/**
* Function to convert a Formal SignWriting in ASCII (FSW) to SignWriting in Unicode 8 (uni8)
* @function convert.fsw2uni
* @param {string} fswSym - an FSW symbol key
* @returns {string} SignWriting in Unicode 8 character(s)
* @example
* convert.fsw2uni('S10000')
* 
* return '𝠀'
*/
const fsw2uni = fswSym => {
  let base = parseInt(fswSym.slice(1, 4), 16);
  let fill = parseInt(fswSym.slice(4, 5), 16);
  let rotation = parseInt(fswSym.slice(5, 6), 16);
  return code2uni(base + 0x1D700) + (fill ? code2uni(fill + 0x1DA9A) : '') + (rotation ? code2uni(rotation + 0x1DAA0) : '');
};

/**
* Function to convert a SignWriting in Unicode (SWU) to SignWriting in Unicode 8 (uni8)
* @function convert.swu2uni
* @param {string} swuSym - an SWU symbol
* @returns {string} SignWriting in Unicode 8 character(s)
* @example
* convert.swu2uni('񀀁')
* 
* return '𝠀'
*/
const swu2uni = swuSym => {
  const symcode = swuSym.codePointAt(0) - 0x40001;
  const base = parseInt(symcode / 96);
  const fill = parseInt((symcode - base * 96) / 16);
  const rotation = parseInt(symcode - base * 96 - fill * 16);
  return code2uni(base + 0x1D800) + (fill ? code2uni(fill + 0x1DA9A) : '') + (rotation ? code2uni(rotation + 0x1DAA0) : '');
};

export { code2uni, fsw2uni, swu2uni, uni2code, uni2fsw, uni2hex, uni2swu };

/* the end */