Allocation of Lambdas that capture "this"

[Zhong Yu]

On Mon, Oct 13, 2014 at 1:12 PM, Neal Gafter <neal at gafter.com> wrote:
> On Wed, Aug 20, 2014 at 4:58 PM, Zhong Yu <zhong.j.yu at gmail.com> wrote:
>>
>> Is there any reason not to initialize the field directly? like
>>
>> final Consumer<Msg> readHandler = (Msg obj)-> {
>>     this.doSomethingWith(obj);
>>     ...
>> };
>
>
> You are not allowed to access "this" in a field initializer.

Apparently it is allowed, according to javac.

What's not allowed is to reference a final field that "might not have
been initialized" when the lambda is constructed; which I think is
unnecessarily strict and inconvenient for many legitimate use cases.

    final Runnable r = ()->{ this.o.toString(); }; // javac error

    final Object o; // assigned in constructor

It can be worked around by obfuscating `this`

    final Runnable r = ()->{ (this).o.toString(); }; // ok

Zhong Yu
bayou.io