message: added isInteger helper
diff: @@ -47,3 +47,9 @@ export function getArrayDigitCount(xs: ArrayLike<number>, maxDigits: number, del
  }
  return { mantissaDigits, integerDigits };
  }
  +
  +export function isInteger(s: string) {
  + s = s.trim()
  + const n = parseInt(s, 10)
  + return isNaN(n) ? false : n.toString() === s
  +}
  \ No newline at end of file
  