Validating email

How should I check if the input is an email address in Flutter?Stack Overflow

extension EmailValidator on String {
  bool isValidEmail() {
    return RegExp(
            r'^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$')
        .hasMatch(this);
  }
}

how to use

TextFormField(
  autovalidate: true,
  validator: (input) => input.isValidEmail() ? null : "Check your email",
)