Convert hex string to int should exit.

[terrylucas]

Following function should exist in Dart's built in library. Currently, it's implement in the lib/ui style.dart file.

  /**
   * [hex] hexidecimal string to convert to scalar.
   * returns hexidecimal number as an integer.
   * throws BadNumberFormatException if [hex] isn't a valid hex number.
   */
  static int hexToNum(String hex) {
    int val = 0;

    int len = hex.length;
    for (int i = 0; i < len; i++) {
      int hexDigit = hex.charCodeAt(i);
      if (hexDigit >= 48 && hexDigit <= 57) {
        val += (hexDigit - 48) * (1 << (4 * (len - 1 - i)));
      } else if (hexDigit >= 65 && hexDigit <= 70) {
        // A..F
        val += (hexDigit - 55) * (1 << (4 * (len - 1 - i)));
      } else if (hexDigit >= 97 && hexDigit <= 102) {
        // a..f
        val += (hexDigit - 87) * (1 << (4 * (len - 1 - i)));
      } else {
        throw new BadNumberFormatException("Bad hexidecimal value");
      }
    }

    return val;
  }

[kasperl]

Added Triaged label.

[andersjohnsen]

To convert a hex-string to an integer, do one of the following:

  int.parse(hexString, radix: 16);

or

  int.parse("0x$hexString");

as a prefix of 0x (or -0x) will make int.parse default to radix of 16.

---

Added Fixed label.