Method performDecode

src/Encoder/MorseCode.js:190–247

* Performs decode on given content. * @protected * @param {Chain} content * @return {number[]|string|Uint8Array|Chain|Promise} Decoded content

(content)

   * @return {number[]|string|Uint8Array|Chain|Promise} Decoded content
   */
  performDecode (content) {
    const representation = this.getSettingValue('representation')
    let string = content.getString()

    let shortMark = '.'
    let longerMark = '-'
    let spaceMark = '/'

    if (representation === 'code') {
      shortMark = this.getSettingValue('shortMark').getString()
      longerMark = this.getSettingValue('longerMark').getString()
      spaceMark = this.getSettingValue('spaceMark').getString()
    }

    if (representation === 'timing') {
      // Interpret timing code
      const fromMarks = [
        this.getSettingValue('signalOnMark').getString(),
        this.getSettingValue('signalOffMark').getString()]

      string = MorseCodeEncoder.translateMarks(
        string, fromMarks, ['=', '.'])

      // Translate timing code to morse code
      string = string
        .replace(/===/g, '-')
        .replace(/\.{7}/g, ' / ')
        .replace(/\.{3}/g, ' ')
        .replace(/\./g, '')
        .replace(/=/g, '.')
    }

    // Translate morse code to string
    string = string
      // Split characters by space
      .split(' ')
      // Decode each character
      .map(rawCode => {
        if (rawCode === '') {
          return null
        }

        const char = MorseCodeEncoder.decodeCode(
          rawCode, shortMark, longerMark, spaceMark)

        if (char === null) {
          throw new InvalidInputError(
            `Code '${rawCode}' is not defined in morse code`)
        }
        return char
      })
      // Leave out codes that are not defined
      .filter(char => char !== null)
      // Glue it back together
      .join('')

    return string
  }