Annotating the receiver

Java does not permit the receiver (the this formal parameter) to be written explicitly on a method in an anonymous class. Therefore, it is not possible to write an annotation on it.

However, it is sometimes necessary to write an annotation on the (inexpressible) receiver.

I propose that the following two syntaxes should have identical effect:

  void myMethod(@Anno MyClass this, int x) { ... }

  @ReceiverQualifier(Anno.class)
  void myMethod(int x) { ... }

Work can occur in the issue2433 branch, which has rudimentary documentation and defines the @ReceiverQualifier annotation (but has no test cases yet).