Hi Pawel,
I will ignore your mistakes and just mention that it is a known problem -
the way lambdas are typed in Java 8 is quite annoying for us. That is why
you have to specify the type. But if I recall, this should work to at least
be a little more concise:
MapElements.via(new SimpleFunction(<lambda>){})
Kenn
On Wed, Apr 25, 2018 at 9:52 AM Pawel Szczur <[email protected]> wrote:
> This email has at least 3 mistakes, please ignore it. I need to rethink it.
>
> 2018-04-25 18:45 GMT+02:00 Pawel Szczur <[email protected]>:
>
>> Hi,
>>
>> I'm using Beam since Google Dataflow has been made public.
>> There used to be MapFn. Some time later it was removed.
>>
>> Now we have MapElements helper which kind of is suppose to do similar
>> things.
>> Using it with new Java 8 API seems pretty ugly to me, especially when I
>> have something like:
>>
>> PCollection<KV<Class1, Class2>> input = ...;
>> input.apply(
>> MapElements.into(*?*).via(v -> KV.of(newKey(v.getKey()),
>> v.getValue()));
>>
>> I would need to replace *?* by KVCoder.of(KeyCoder.of(),
>> ValueCoder.of()).
>> This is troublesome especially when in a longer transformation chains.
>>
>> For me, it's became easier to write:
>> input.apply(DoFn(new ReplaceKey()))
>> where ReplaceKey is a implementation of SimpleFunction defined somewhere
>> and just replacing KV's key.
>>
>> I'm wondering, am I missing something?
>>
>> Cheers, Paweł Szczur
>>
>>
>>
>>
>
