Method calls vs lambda calls

[Howard Lovatt]

Yes that is a forth option; but it is confusing because people expect
generic types to behave like concrete types (that's the point of
generics). Anomalous behavior of generics, e.g. interaction with
arrays, is already a problem and this option will only increase the
problems. For example the following would work with the option I
listed as 2, but not with this fourth option:

class Base<T> { T t; }
class Reasonable extends Base<List<Integer>> {
  { t = new ArrayList<Integer>(); }
  void reasonable() { t.add( 1 ); }
}
class Unreasonable extends Base<#int()> {
  { t = #int() (42); }
  void unreasonable() { out.println( t(); } // Error, T is not
behaving as a #int()
}

If in reasonable() I can treat T as a List, why in unreasonable()
can't I treat T as a #int()? (Ok in some circumstances I can treat T
as a #int(), but not in all.)

 -- Howard.

2009/12/17 Neal Gafter <neal at gafter.com>:
> On Thu, Dec 17, 2009 at 12:02 AM, Howard Lovatt <howard.lovatt at iee.org>
> wrote:
>>
>> Based on Neal's generic example, here is a particularly nasty case:
>>
>> class Base<T> {
>>  T t;
>>  T t1;
>>  void t() { out.println( t ); }
>> }
>>
>> class Derived extends Base<#int()> {
>>  {
>>    t = #int() (42); // Can't override t() because it has a different
>> signature
>>    t1 = #int() (41);
>>  }
>>  void test() {
>>    out.println( t1 ); // Prints Function_intATXXX
>>    out.println( t1() ); // Would be nice if this printed 41
>>    out.println( t ); // Prints Function_intATXXX
>>    out.println( t() ); // Error t() returns void
>>  }
>> }
>> ...
>> Can anyone think of any other options?
>
> Yes: a variable is added to the method namespace only when declared with a
> function type.  In this example, t and t1 are not declared with a function
> type, but rather are declared with the type of a type parameter (T).
> Therefore shorthand invocation is not available for them.
>
> This is a nice solution because it prevents names being inherited into a
> namespace in which they did not previously appear.
>
> Cheers,
> Neal
>
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