Method unhex

java/com/google/re2j/Utils.java:22–33

(int c)

  // If |c| is an ASCII hex digit, returns its value, otherwise -1.
  static int unhex(int c) {
    if ('0' <= c && c <= '9') {
      return c - '0';
    }
    if ('a' <= c && c <= 'f') {
      return c - 'a' + 10;
    }
    if ('A' <= c && c <= 'F') {
      return c - 'A' + 10;
    }
    return -1;
  }

  private static final String METACHARACTERS = "\\.+*?()|[]{}^$";