/*****************************************************************
  Followed is typechecking of the create expression
  None of the expressions, unless noted otherwise, typecheck
 ******************************************************************/  


classage X {

  void t() {

    //M does not exist
    //create M();

    //If a classage does not define constructors expicitly,
    //the only valid constructor is the default one.    
    create Z(3);

    //If a classage does explicitly define constructor(s), 
    // the default constructor is not added.
    create W();

    //can not find an appropriate constructor; does not exist at all
    create U(3);

    //can not find an appropriate constructor; subtyping violation
    create U(create Sub2());


    // type mismatch on assignment, a test on return type
    int x = create U();


    // however the following works
    U z = create U(); 

  }


}




/*****************************************************************
  Followed is typechecking of atomic classage constructors
  None of the expressions, unless noted otherwise, typecheck
 ******************************************************************/  


classage Atomic1 {

   // a constructor must have the same name as the classage name
   // Atomic2() {}
}


classage Atomic2 {

   // disallow this syntax. Only allow "this" call in atomic classages
   Atomic2() { :Atomic3(); }
}


classage Atomic3 {

   // can not find appropriate constructor, does not exist at all
   Atomic3() { this(true); }

}


classage Atomic4 {

   // can not find appropriate constructor, subtyping violation
   Atomic4() { this(create Sub2()); }

   Atomic4(Sub1 x) { }

}




/*****************************************************************
  Some definition used by above
 ******************************************************************/  



classage U {
   mixer E {
     export void a(int x) {}
   }

   U() { }
   U(Sub1 x) {}
}



classage W {
   W(int x) {}

}

classage Z {

}


classage Sub1 {

  connector E {
	export void a() { return; }
  }

}

classage Sub2 {

  connector E {
	export void a() { return; }
	import void c() 
  }

}