private static function extractOptions()

in src/CLIBase.hack [292:334]
43 lines of code
8 McCabe index (conditional complexity)

  private static function extractOptions(
    string $arg,
    CLIOptions\CLIOptionType $type,
  ): dict<string, ?string> {
    $options = vec[];
    switch ($type) {
      case CLIOptions\CLIOptionType::LONG:
        $options[] = $arg;
        break;
      case CLIOptions\CLIOptionType::SHORT:
        $equal_sign_position = Str\search($arg, '=', 0);
        if ($equal_sign_position !== null && $equal_sign_position !== 1) {
          throw new InvalidArgumentException(
            'It is restricted to use value assignment in multiple usage of short syntax: -%s',
            $arg,
          );
        }
        if ($equal_sign_position === null) {
          $options = Vec\concat($options, Str\chunk($arg));
        } else {
          $options[] = $arg;
        }
        break;
      default:
        break;
    }
    $is_single_option = C\count($options) === 1;
    if ($is_single_option) {
      $value = null;
      $option = C\onlyx($options);
      if (Str\contains($option, '=')) {
        $parts = Str\split($option, '=');
        $option = $parts[0];
        $value = Str\join(Vec\drop($parts, 1), '=');
      }
      $result = dict[
        $option => $value,
      ];
    } else {
      $result = Dict\fill_keys($options, null);
    }
    return $result;
  }