Indexing access for Lists and Maps considered harmful?

[Neal Gafter]

On Tue, Jun 23, 2009 at 11:12 AM, Joseph D. Darcy <Joe.Darcy at sun.com> wrote:

> Neal Gafter wrote:
>
>> Why would a language-support method like Puttable.put return a value that
>> the generated code is required to ignore?
>>
>
> I am not proposing that the value is required to be ignored.  My current
> thinking is that compiler warnings are sufficient to deal with the multiple
> assignment situation in indexed access.  Aggregates outside
> java.util.Collection could choose to be Puttable<KeyType, Void.class> to
> avoid having to return some value.


That still requires the implementation to return something to be ignored
(null), and is not parallel the the language's existing semantics for
assignment expressions.