code: function isOkCharCode(code, base, radixPointOk) {
    // Check against each character in consts.alphabet up to the specified base.
    for (let i = 0; i < base; i++) {
      let okCode = consts.alphabet[i].charCodeAt(0);
      if (code == okCode || (!consts.caseSensitive && code == changeCase(okCode))) return true;
    }
  
    // Conditional exception for the radix point.
    if (radixPointOk && code == consts.point) return true;
  
    // If you get this far, the code is not ok.
    return false;
  }
docs: /* Check if a character code represents a valid character in the specified base.
  * Case insensitive unless consts.caseSensitive is true.
  *