template for porting Palindrome.java to dart

main.dart

// refer to the Java code here:
// https://gist.github.com/rjlutz/3c26a1be877529de8dd28049d12415d0
// complete the dart implementation below to have the same functionality

class Palindrome {
  // TODO implement check
  static check(String s) {
    return true;
  }
}

// lambda to mimic Java's Character.isLetterOrDigit()
bool isLetterOrDigit(String s, int idx) => s[idx].contains(RegExp(r'[\da-zA-Z]'));

main() {
  
  // should result in true,false,true,false,true,false
  
  print(Palindrome.check('radar'));
  print(Palindrome.check('raxdar'));

  print(Palindrome.check('noon'));
  print(Palindrome.check('nxoon'));

  print(Palindrome.check('Rise to vote, sir!'));
  print(Palindrome.check('Rise to xyz vote, sir!'));
}