overload resolution with deep nested lambda

[anna.kozlova at jetbrains.com]

Hi,

sorry if the place is inappropriate, hopefully explanation would be 
interesting not only for me.

The following sample compiles, though my understanding of the spec says 
that it should not:

{code}
class Main {
     public static void main(String[] args) {
         List<Optional<Function<String, String>>> list = 
asList(of((String s) -> identity(s)));
     }

     static <T> List<T> asList(T a) { return null;}
     static <T> List<T> asList(Optional a) { return null;}

     static <O> Optional<O> of(O value) { return null;}

     public static String identity(final String s) {
         return s;
     }
}
{code}

Because of((String s) -> identity(s)) is potentially compatible with 
both methods (15.12.2.1), method applicability search yields 2 methods 
applicable by strict invocation, of which asList(Optional a) is more 
specific (according to 18.5.4) but javac obviously chooses asList(T).

Could someone explain what have I missed here please?

Thank you,
Anna