Method substr

src/Chain.js:194–204

* Returns the characters in a string beginning at the specified location * through the specified number of characters. * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/substr * @param {number} start * @param {number} [length] * @return {Ch

(start, length = undefined)

   * @return {Chain}
   */
  substr (start, length = undefined) {
    if (length <= 0 || start >= this.getLength()) {
      return Chain.empty()
    } else if (start < 0) {
      start = Math.max(this.getLength() + start, 0)
    }

    const codePoints = this.getCodePoints()
      .slice(start, length ? start + length : undefined)
    return Chain.wrap(codePoints, this._encoding)
  }

  /**
   * Truncates chain to given length and adds ellipsis if truncated.