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

/**
* Sutton SignWriting Unicode 8 Module v1.1.2 (https://github.com/sutton-signwriting/unicode8)
* Author: Steve Slevinski  (https://SteveSlevinski.me)
* symbol.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]
  };
};

/**
 * Function to compose symbol string from object
 * @function symbol.compose
 * @param {object} symbolObject - an object of symbol parts
 * @param {string} symbolObject.base - base character for symbol
 * @param {string} symbolObject.fill - fill character for symbol
 * @param {string} symbolObject.rotation - rotation character for symbol
 * @returns {string} symbol string 
 * @example 
 * symbol.compose({
 *  'base': '𝠀'
 * })
 *
 * return '𝠀'
 */

const compose = symbolObject => {
  if (typeof symbolObject !== 'object' || symbolObject === null) return undefined;
  const sym = (symbolObject.base ? symbolObject.base : '') + (symbolObject.fill ? symbolObject.fill : '') + (symbolObject.rotation ? symbolObject.rotation : '');
  return sym ? sym : undefined;
};

export { compose, parse, re };

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