Function format

src/utils/string.js:54–61

(value, options)

 * @return {string} str
 */
export function format (value, options) {
  const result = _format(value, options)
  if (options && typeof options === 'object' && 'truncate' in options &&
      result.length > options.truncate) {
    return result.substring(0, options.truncate - 3) + '...'
  }
  return result
}

function _format (value, options) {
  if (typeof value === 'number') {