all files / music-notation/accidentals/ parse.js

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'use strict'
 
var R = /^(#{1,}|b{1,}|x{1,}|)$/
 
/**
 * Given an accidentals string returns its alteration number
 *
 * @param {String} accidentals - the accidentals string
 * @param {boolean} skipValidation - true to skip validation
 */
module.exports = function (str, skip) {
  if (!skip && !R.exec(str)) return null
  var alt = str.replace(/x/g, '##').length
  return str[0] === '#' ? alt : -alt
}